AND 
GM Explains Why the 1.4 L ICE Range Extender was Chosen For the Volt
On Friday GM dedicated a new advanced powertrain engineering center in Pontiac Michigan. The 450,000 square foot, $450 Million facility will use new specialized technology and procedures to more rapidly roll out advanced fuel efficient powertrains. It should be able to cut 10 weeks off of the typical powertrain development cycle. The Volt’s hardware will take center stage at the facility and per GM, "the Volt’s electric drive unit, motors, power electronics and engine will be tested in this center."
At the dedication, automotive blogger Sam Abuelsamid had the chance to interview GM’s executive director of hybrid powertrain engineering, Larry Nitz, about why GM went with the 1.4 L non-turbo 4 cylinder engine and found out some other interesting things.
For one thing, per Nitz, "the 1.4L NA four has better brake-specific fuel consumption than the 1.0L turbo when used in steady state mode, as it will be in the Volt application."
Also Nitz claims the four cylinder engine will provide for a smoother transition from EV to range extension saying "the objective is to keep the engine off and when the engine comes on, you don’t want to know it’s on. You want it really smooth and four cylinder is smoother than a three."
Nitz also noted that the four cylinder has a lower cost and that when the turbocharging architecture is added to the 3-cylinder engine, the non-turbo four cylinder engine setup is actually lighter.
Since the four cylinder engine is also longer, GM has had to reconfigure the packaging somewhat to make it fit, which as per Nitz is "turning out nice."
Nitz goes on to say the generator produces 50 kw, whereas the electric motor produces 100 kw, and assures us that the "vehicle will never use more than 50kW on a continuous basis," and says "zero to sixty, passing maneuvers, you’ll be fine, the ability to actually use more than about 50kW doesn’t exist very frequently."
He notes that the engine never has to perform dynamic response, that only comes from the battery and electric motor side.
Nitz also states that GM has refined the charging window of the pack as 35% to 85%, whereas previously GM had said it would be 30% to 80%. He does say though that the battery could be discharged below 35% if it has to on rare occasions, but that when steady state resumes, the battery will recharge as the engine then produces more output than the car requires at that time.
And yes that’s the actual Chevy Volt range extender in the graphic above (Thanks BillR)
Source (GM ) and (Green Fuels Forecast )
[UPDATE: Sam Abuelsamid indicates that Nitz did not specifically say the available charge window would be 35% to 85%, but rather that was Sam's understanding from discussions with others at GM, slightly different than the information I had been given of it being 30% to 80%]
July 26th, 2008 at 3:39 pm
Excellent information!
July 26th, 2008 at 3:48 pm
Great post with great information.
OMG — these guys may actually know what they are doing! I paticularily liked this part, which is substantially different than the conjecture (claims?) on the related threads that the 1.4 was between a thousand and a couple hundred pounds heavier:
“Nitz also noted that the four cylinder has a lower cost and that when the turbocharging architecture is added to the 3-cylinder engine, the non-turbo four cylinder engine setup is actually lighter.”
GM engineering is not usually the issue. The issue is whether GM can build the vehicle with reasonably few manufacturing defects.
July 26th, 2008 at 3:49 pm
it will be interesting to see how they mount this with the electric motor. I assume they would want the electric motor to drive the front wheels which places it in under the hood area. So where does the ICE/GEN mount? Or will the electric motor drive the rear wheels?
July 26th, 2008 at 4:07 pm
Wow, that picture looks complex. I hope most of that stuff is used for assembly/testing, because I keep hearing that EV has much fewer parts than today’s cars. Maybe that is only for pure EV and the Volt ER-EV will actually have MORE parts than today’s vehicles. I think my head is starting to hurt (it might just be a maintenance headache).
July 26th, 2008 at 4:18 pm
The 1.4 is an excellent decision, and will be smoother, lower maintenance, lower cost and hopefully more trouble free than the 1.0 turbo. Voltik on this site had stated that the 1.0 would have had to operate at about 3k rpm to pull it’s duty whereas the 1.4 can get by at about 1.8K, this alone could result in fuel savings, so this is good news.
R.E. will be with EVs for some time so I’ve got to believe over the next few generations there will be much progress in their efficiency. It’s also good to know for certain that the ICE will be flex-fuel capable, many may remember that about a year or so ago there was some doubt about this.
July 26th, 2008 at 4:23 pm
Is that an inline-4 or a V-4 ?
Is than OHV or SOHC or DOHC ?
Are those cast pistons or forged ?
Is that cast iron block or aluminum or ceramic ?
Just how good is that motor anyway ?? (i hope GM knows what it is doing)
July 26th, 2008 at 4:24 pm
I’m impressed. It’s comforting to see something tangible.
Wouldn’t it be great if GM announced they were just keeping the competition off guard and they will actually be releasing 100,000 Volts in Jan 2009 at $18,000?!
July 26th, 2008 at 4:24 pm
I find it interesting that the engine will run in “steady state”. Doesn’t that mean constant RPM? Several of us had argued that point a long time ago on the basis of fuel efficiency, and I thought that GM confirmed that the engine would instead behave dynamically. Looks like they changed their mind on that one, and now would rather the driver not even realize it kicked on! Nice.
July 26th, 2008 at 4:26 pm
#4,
that doesn’t look complex at all, I see air induction, some electronics at the top, I see the block and I see the output shaft from the engine going to what looks like a generator and a bunch of stuff around it holding it in place and purhaps equipment for testing.
July 26th, 2008 at 4:29 pm
#7 akojim:
I want some of that GM koolaid yur drinkin’
July 26th, 2008 at 4:31 pm
Does this mean that the Volt will have dual exhaust pipes (that would look cool).
July 26th, 2008 at 4:32 pm
keep yer hands off my koolaid!
July 26th, 2008 at 4:35 pm
“Nitz also states that GM has refined the charging window of the pack as 35% to 85%, whereas previously GM had said it would be 30% to 80%. He does say though that the battery could be discharged below 35% if it has to on rare occasions, but that when steady state resumes, the battery WILL RECHARGE as the engine then produces more output than the car requires at that time”.
Can I really believe it? GM actually making the Volt better, not worse? I said before, it makes no sense to have that 4-cyl powerhouse turning the generator, only to waste the excess generated power instead of recharging the battery with it (at a rate the battery can safely take). The Volt is starting to make sense again. Use every bit of generated power you can. Use the ICE to power the electric motor while charging the Volt’s battery. Anything else just doesn’t make sense to me.
July 26th, 2008 at 4:40 pm
Nitz goes on to say the generator produces 50 kw, whereas the electric motor produces 100 kw
Is this a typo?
Should it read:
the generator produces 100 kw, whereas the electric motor uses 50 kw.
“vehicle will never use more than 50kW on a continuous basis”
This quote seems to support this, but I don’t know the generator output.
July 26th, 2008 at 4:41 pm
I think when you turn on the A/C that gasohol engine will be ON. (unconfirmed)
July 26th, 2008 at 4:56 pm
Russel #14:
The drive motor will produce 50 kW in normal driving, but more than that (apparently up to 100 kW) in “peak conditions”, i.e. acceleration.
Presumably that 100 kW would come exclusively from the battery in the first 40 miles, and then after that 50 kW would come from the generator and 50kW would come from the battery (which has been minimally recharged by the generator in low-demand driving).
July 26th, 2008 at 4:58 pm
What is that silver casing on the left side of the engine ? The generator ?
July 26th, 2008 at 5:07 pm
#14 Russell — I think the quote is correct. As I read the interview, what he was saying is that if the engine is on, and there is a need for more power over and above the 50kW the engine can supply, the battery would supply it, in which case the charge would fall below 35%. However this would be temporary and when the need passed, the engine would recharge the battery since the “vehicle will never use more than 50kW on a continuous basis”.
July 26th, 2008 at 5:08 pm
Russell, wattage has usage outside of electricity. It is just a unit of energy. Whether electric or propulsion.
July 26th, 2008 at 5:09 pm
I would like to know is the engineer Bob Lutz wearing a fake beard ?
July 26th, 2008 at 5:11 pm
The question about the air conditioning seems important. GM said one of their first release areas will be FL. I live in FL. FL gets hot (today it was over 90° on the other side of my containment). If the little engine has to run all the time when the AC is on, that would kind of reduce the [insert current guess] all electric range to zero. That would make the Japanese “P car” a better deal. Since that doesn’t make sense, can I assume running the AC will just reduce the all electric range, but not eliminate it? Maybe I could still get 15-20 miles?
July 26th, 2008 at 5:18 pm
Some interesting new details.
Among them, they’ve changed the “setpoint” (up 5%).
Unless I see some hard info / a new chart from GM, I still have to believe the ICE / Generator WILL NEVER BE ALLOWED TO RECHARGE THE PACK TO 85% (the new “FULL” point).
As I’ve stated before, the characteristics of the cells in the pack are well known. The design team knows what to do to make the pack last. As the earlier GM charts show, THE LARGE RECHARGE SWING WILL ONLY OCCUR WHEN IT’S PLUGGED IN. They may have revised the narrow window of pack charge where the ICE / Generator can operate.
Perhaps it now can only run in the 30% – 40% range.
Lyle, can you please quiz someone at GM about this important past detail ?
Thanks.
July 26th, 2008 at 5:22 pm
Looks like GM is batting 1000. They are making the right decisions. Now let’s get the Volt on the road.
July 26th, 2008 at 5:44 pm
Russell @ 14, yes I think the Volt has a 53 KW generator, and a 120 KW electric drive motor. The idea is that under normal load conditions, say going down the highway at 65 MPH, the motor will be drawing about 23 KW of power from the battery. And if the state of charge of the battery is less than the ICE start point, the generator will also be in operation, charging the battery back up above the ICE start point. And to do that it will have to generate more than 23 but not more than about 50 KW.
In the case where you are trying to accelerate to 60 MPH in less than 9 seconds, you will be drawing more than 50 KW from the battery, but only for a few seconds, for once you reach your desired speed, your draw rate will drop back below 25 KW.
July 26th, 2008 at 6:08 pm
4 banger @ #15,
“I think when you turn on the A/C that gasohol engine will be ON. (unconfirmed)”
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That is false. It has already been confirmed the Volt will use an electrically operated “heat pump.” ICE driven air conditioner compressors are a sore point for vehicles such as the Ford Escape hybrid. Unlike the Prius and Civic hybrids, mild hybrids and some of the other hybrids must have the ICE running to cool the vehicle. Not true with the E-Flex drivetrain or advanced hybrids like the Prius. They also have electrical assist for power steering and brakes.
Also, any of the hybrid vehicles are much more complicated and have many more “parts” than pure BEV’s or ICE powered vehicles, making the basic hybrid vehicle construction more expensive. Then you have to add the cost of the battery pack.
I also see some posters keep speaking of “low maintance costs” vs. an ICE powered vehicle. If the vehicle has an ICE onboard, the engine has to be maintained like any other ICE engine, oil changes, air filters, etc. Such maintance will probably be time based rather than mileage based and not as frequent, but will still have to be done.
July 26th, 2008 at 6:11 pm
That looks like an inline 4 which may not be optimal design since I believe a V-4 would generate much more low RPM torque (at least they do in the motorcycle world).
July 26th, 2008 at 6:13 pm
Seems a BUNCH of people in the previous thread didn’t know squat about what they were talking about. Thanks for the quick follow up to put on the “I know better than GM” speculation to bed.
And now this thread is again filled with a bunch of uninformaed posters as well. *sigh*
July 26th, 2008 at 6:20 pm
Omega #27
Yup, but it’s not worth huffing and puffing about. I just treat them like P.D.F.T.T. and move on. Now it would be different if newbs were asking a genuine question.
July 26th, 2008 at 6:34 pm
#6 Four Banger.
Most likely it’s aluminum. Most are these days.
“V” 4 is very unlikely. Look for an inline 4 or I4
Forged pistons are needed for hi temperature, hi rpm and hi performance applications. They are noisy until they heat up.
They are not needed as this will be a slow spinning engine with little stress. Cast is just fine or hyperutectic which allows great tolerances
All GM engines are OHV. Old lawn mover engines have valves in the block.
Single Cam or Twin cam….depends on benefits of weight and the particular efficiency needed at a low rpm.
Efficiency and cost to produce will dictate.
July 26th, 2008 at 6:37 pm
#9 and #4 – What it looks like to me in the picture is this:
The engine is obvious, I believe the electric motor is encased in what looks like would be the transaxle in a normal car. From the transaxle you can see the two axle shafts extending to dynamometers where the front wheels will be in the actual car.
So for the casual observer, it would look like a standard engine/transmission, only the “transmission” will be the casing where the electric motor is housed instead.
July 26th, 2008 at 6:42 pm
Thinking about my post a little more, it looks like we can also surmise that the range extender engine and electric drive motor for the car will be physically mated together.
No more thoughts of quickly swapping out the ICE range extender for the future fuel cell range extender I guess.
July 26th, 2008 at 6:42 pm
I have been driving an EV (Tango) for more than 2 years now. It goes 0 to 60 in less than 4 seconds, 150 mph, and more than 80 mile range. I love my Tango.
July 26th, 2008 at 6:42 pm
#8 Jim G says: “I find it interesting that the engine will run in “steady state”. Doesn’t that mean constant RPM? Several of us had argued that point a long time ago on the basis of fuel efficiency, and I thought that GM confirmed that the engine would instead behave dynamically. Looks like they changed their mind on that one, and now would rather the driver not even realize it kicked on! Nice”
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Actually, “steady state” could mean a number of things. I think the gist of Nitz’s information is aimed at reinforcing the idea that the ICE provides only average power, not peak power. So “dynamic” is Nitz’s term for peak power transients, and “steady state” is the average power. Average power is probably calculated over some number of seconds, so average power will vary a lot, which means variable RPM is quite possible. At least, that’s how I interpret it.
Lyle,
Could you ask GM if the ICE will be constant RPM or variable RPM?
July 26th, 2008 at 6:42 pm
57 >> ICE driven air conditioner compressors are a sore point for vehicles such as the Ford Escape hybrid. Unlike the Prius and Civic hybrids, mild hybrids and some of the other hybrids must have the ICE running to cool the vehicle.
Huh? It’s only the ASSIST hybrids (BAS & IMA) which depend on the engine running to cool.
Taking the new model Escape-Hybrid into account, all FULL hybrids have electric A/C.
July 26th, 2008 at 6:45 pm
Volt will use 100KW motor instead of 120KW ?
Honda Clarity also uses 100KW motor and its 0-60 is 10 sec.
Will the Volt 0-60 also be 10 sec ? or will it be better than that ?
July 26th, 2008 at 6:50 pm
I like this quote from Larry Nitz: “the objective is to keep the engine off and when the engine comes on, you don’t want to know it’s on. You want it really smooth and four cylinder is smoother than a three.”
I think people are going to expect their Volt to be a quiet running car. I’d like to not even notice that the IC engine is on unless I had the radio off, etc. Once the nice, quiet “all electric range” of 40 miles runs out, it would be a bummer to have to hear a noisy IC engine kick in when it has to go into “charge sustaining mode”.
In fact, GM would be smart to use one of their very best mufflers for the Volt. They should also put a bunch of soundproofing materials around the Volt to keep that IC engine sound and tire road noise out of the cabin of the Volt.
People that want that IC engine noise might could buy an OPTIONAL computer controlled external noise generator if they just have to have it. It could play IC engine noises that are in sync with electric motor speed or whatever. They need to put a maximum volume control on it though, so people don’t drive around with it cranked up all the time. Teenagers on Friday nights might do this. The world has enough noise pollution as it is. Pedestrians with good hearing would get sick of that noise pretty quick.
I wouldn’t be surprised if the government passed a law requiring external noise generators because of blind and deaf people. If they do, they should make it so the blind people hear the noise … NOT the people riding in the Volt. Soundproofing is needed or Volt owners would get sick of that annoying sound.
Maybe someone will come up with some other technology for blind and deaf people so you don’t need external noise generators on electric cars. Some sort of white cane or small beeper that makes noise or vibrates when it detects a signal from an oncoming electric car?
There won’t be many electric cars on the road for awhile so this won’t be that much of a problem. Maybe in 2014+, it could be a problem though. It’s something the engineers ought to be thinking about though. It’s just one of many unforeseen things that they ought to be brainstorming about BEFORE the Volt hits the streets.
They might not think of certain things when the Volt is in the R&D center. GM still needs to have people drive the production version of the Volt around in real world conditions for maybe 6 months and try to anticipate any problems that might come up. I want very little bad publicity about the Volt in 2011 once people start driving them.
July 26th, 2008 at 6:50 pm
If they make electric power steering, electric-assist brakes, electric heat pumps, D-class stereo amps and all these other high-efficiency electric devices WHY are they not in every car made ???
July 26th, 2008 at 6:51 pm
100KW = 134 horsepower, and 50KW = 67 horsepower.
http://www.mr2ownersclub.com/converter.htm
By the way, both of these numbers are lower than GM quoted previously. It used to be 120KW (160 hp) and 53KW (71 hp).
July 26th, 2008 at 6:54 pm
Dangit! I’ll say it again. GM is using an sub-optimal off the shelf engine instead of the *right* engine.
on the highway the volt will only draw at most 16 kw to maintain 65 mph on flat open road. (this correlates with 30 mi. highway AER). Not 25kw like another poster alluded to (which would correlate to a 20 mi highway AER).
JUST LIKE I”VE BEEN SAYING. An ice in genset mode likely produces optimal torque around 50% peak output. This is now confirmed by GM engineers. Can the people who call’d folk like me an ‘armchair engineer’ please apologize? I doubt it.
Okay, so the 1.4 L, Natrually Aspirated 4 banger is more cost effective than the 1.0L Turbo- 3 banger. I think we already knew that. We now know that there is no weight penalty. Great! BUT, #DA’s old point will not die like the ghost of Christmas past.
If the typical ER driving condition is flat 65 mph road, then 50kw output minus ~15KW draw results in a 35 kw surplus. This is a charge rate of about 2C. Thus the LIONs, when they hit the “charge sustaining point” of 35%, will begin being continuously charged at 2C for just over ~2.5 minutes to achieve a 45% SOC, which I imagine will be the cycle down point out of Charge Sustaining Mode. Now within 6 minutes of continued ER driving, your Lions will drop back to the Charge Sustaining Cut-In point of 35%. Thus, in ER highway driving, you will be wearing a 1/10th cycle every 8.5 minutes (9miles).
Lets convert that to cycles/mile shall we! 9 / 10% = 90 miles of ER highway driving/ cycle. Lets just call it 100mi/cycle to make life easy for us.
So assuming you drive 60 hwy miles a day (30 AER, 30 ER), you will place a 1/2 cycle on your pack from the AER, and another .3 cycles for ER driving. Thus, ER driving per mile, is almost as much wear as AER driving.
So assuming you drive 60 miles hwy a day, 250 business days a year, after about 7 years you clock 105K miles, and 1400 cycles on your volt’s lion. ( remember 875 AER cycles, and 525 ER cycles)
Now my point is illustrated as to why this 1.4L 100kw peaking engine is too large. fuel efficiency aside, you’ve clock way too many lion cycles in ER mode.
If you rework the math with a 60 kw peak engine, and 30 kw peak genset, you greatly reduce ER lion cycling.
Not bad for an ‘arm chair’ engineer, eh?”
–
#DA
July 26th, 2008 at 6:58 pm
#36 GM Volt Fan says: “…I wouldn’t be surprised if the government passed a law requiring external noise generators because of blind and deaf people…
There won’t be many electric cars on the road for awhile so this won’t be that much of a problem. Maybe in 2014+, it could be a problem though…”
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Actually, this is a problem now. The Toyota Prius frequently drives in all electric mode below 40mph. CNN ran a story around a month ago about a boy riding a bike that was hit by a Prius. The boy said he couldn’t hear it coming. The CNN piece also mentioned blind people, but kids on bikes seemed to be their primary focus.
July 26th, 2008 at 7:07 pm
Well, I think we all forget something important: The Volt is NOT Open-Source Software. It is a for-profit move (at least in the long-term) and as such, we will NOT know details of the drivetrain, technology, release date, exact operations, production numbers, or the like until it is VERY close to the release, and some of those, not even then. We would very much like (I know I would) to know all there is to know about this thing, I for one plan to buy the Chilton manual as soon as I can and I don’t even change my own oil. But that will have to wait a while. A good chunk of info floating around right now is probably wrong. I doubt the release numbers, for starters, but I don’t know.
Keep an open and skeptical mind! The scientist in me sees a company that is going down the right road, and is (wisely) keeping some things to itself.
I’ll still be in line to get one, even though right now it reminds me more of the Batmobile then anything else.
I’d love to see more stories about the interior development soon.
Thank you, Lyle, for the great update!
July 26th, 2008 at 7:08 pm
From the article:
For one thing, per Nitz, “the 1.4L NA four has better brake-specific fuel consumption than the 1.0L turbo when used in steady state mode, as it will be in the Volt application.”
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OK, can someone translate this for me? I assume NA is non-aspirated, but what exactly is “brake-specific fuel consumption”?
Also, I’m guessing “steady state mode” is when the battery is not discharging to accelerate or drive up a steep hill, and the battery is not charging back to 35% to recover from a recent acceleration or uphill discharge.
July 26th, 2008 at 7:12 pm
Thank you for the air con answers. Don’t listen to everyone who thinks ‘dumb’ questions are just ‘bait’. Living here under a rock, I didn’t know there were electric automotive air conditioners. I usually just keep quiet and learn things here.
July 26th, 2008 at 7:13 pm
#39 #DA says: “on the highway the volt will only draw at most 16 kw to maintain 65 mph on flat open road. (this correlates with 30 mi. highway AER). Not 25kw like another poster alluded to (which would correlate to a 20 mi highway AER).”
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These numbers conflict with what GM said last summer:
http://gm-volt.com/2007/08/29/latest-chevy-volt-battery-pack-and-generator-details-and-clarifications/
“Peak efficiency will be at around 30 kW, which is what the car should require at 65 mph slightly uphill, …”
“Those energy requirements will roughly be about 8 kWh in the city, and 25 kWh on the highway.”
(I’m pretty sure the kWh on the second quote is a typo – should bw kW)
July 26th, 2008 at 7:15 pm
I hope the regenerative braking system in the Volt will be fully adjustable. I prefer to have mine set for harsh braking, that way will almost never need to use the real brakes and also generate max current (~200 amp).
July 26th, 2008 at 7:18 pm
Brake specific fuel consumption – found it:
http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption
July 26th, 2008 at 7:23 pm
“Also Nitz claims the four cylinder engine will provide for a smoother transition from EV to range extension saying ‘the objective is to keep the engine off and when the engine comes on, you don’t want to know it’s on. You want it really smooth and four cylinder is smoother than a three.’”
Just as I suspected. Lutz commented about this.
I’d also like to learn more about the generator.
Do we know for sure that picture is a real Volt drive-train? Something doesn’t look right for it to be an electric drive-train
July 26th, 2008 at 7:31 pm
35. Talks
I read somewhere that Bob Lutz thinks they *might* could program the Volt to go 0-60 in 7 seconds. Up to now, GM has been saying 0-60 mph target is 8.5 seconds. I’m hoping that GM is going to have a pleasant surprise for us and have a 7 second 0-60 time. Who knows? They don’t call him “Maximum Bob” for no good reason.
I think people will expect the Volt to be fairly quick like the Tesla Roadster they’ve been reading about. But, it’s all about the battery and the range and all that. Who knows what compromises they might have to make. I read that the Lightning GT electric car will have 2 driving modes …. performance mode and fuel economy mode. I think GM ought to highly consider doing the same thing.
July 26th, 2008 at 7:32 pm
Forget the Volt, the IRS has decided to give a nice $1300 check to anyone that buys the new Volkswagen Jetta TDI (aka Clean Diesel) available at your favorite dealer around Labor Day. Sorry, Prius owners you don’t qualify. BTW, this vehicle gets 40 MPG.
July 26th, 2008 at 7:40 pm
GM Volt Fan:
Look for a faster Volt SS model. This will simply be a cosmetic overhaul to a normal Volt. Of course to get the reprogrammed chip there will be a $5K premium to get the SS logo (not related to Hitler’s gang).
July 26th, 2008 at 7:44 pm
Great to hear about the new powertrain HQ. I hope they built some comfortable bedrooms into the new building so the Volt team can avoid leaving for any reason
o.Jeff
July 26th, 2008 at 7:50 pm
The Volt GT will come standard with 4 Recaro bucket seats and full safety harness with push-button release. Battery capacity will be doubled and suspension upgraded. Expect 0-60 time around 2.6 seconds and 80 mile range. This will officially be a 2012 model, adjust your insurance rate accordingly.
July 26th, 2008 at 8:11 pm
john1704a @ #34,
“Huh? It’s only the ASSIST hybrids (BAS & IMA) which depend on the engine running to cool.
Taking the new model Escape-Hybrid into account, all FULL hybrids have electric A/C.”
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This is false. The Ford Escape hybrids through the 2008 model have air conditioner compressors driven by ICE engine belts. The 2009 Escape is to have a new ICE, but Ford hasn’t released any info on that model’s compressor that I am aware of. I know of no “American” Big 3 vehicle that has an electric air conditioner compressor. If you do, list the model. In addition to Toyota and Honda full hybrids, the Nissan Altima has an electric compressor. I haven’t researched ALL manufacturors of full hybrid vehicles, but I have the ones I mentioned. I was interested in buying a 2008 Ford Escape hybrid last year until I found out that you have to set the air conditioner control to ‘Max’ to keep the AC blowing cool air while in traffic congestion. Setting the control to Max keeps the ICE running even while stopped at traffic lights, negating much of the fuel savings of having a hybrid.
July 26th, 2008 at 8:16 pm
Dave G. #42
“OK, can someone translate this for me? I assume NA is non-aspirated, but what exactly is “brake-specific fuel consumption”?”
*** *** ***
It’s a measure of efficiency. You basically take the fuel pound consumption per hour and divide by brake HP. Since the Volt’s ICE will run at a fairly reasonable RPM it’s not surprising that the 4-banger beats the turbo-3 in this respect. This would probably change at peak output, but again that’s not the sweet spot they’re targeting.
July 26th, 2008 at 8:17 pm
#42 Dave G
Brake specific fuel consumption is the amount of fuel required to produce a given amount of power. For instance, .40 lbs of fuel per horsepower. This attached link is from a company that is developing diesel engines for small aircraft. They have a brake specific fuel consumption curve for their engine for your inspection.
http://www.deltahawkengines.com/perfor00.shtml
July 26th, 2008 at 8:39 pm
Oh my gosh, is that a HUMAN working on Volt internal components. For Quality Control(QC) and Quality Assurance(QA) it must be mandatory for Volt production to be FULLY automated. Be advised that the primary reason that the Japanese where able to leapfrog the U.S. in Quality in such a short time period was the sale of supercomputers. When the U.S. Government let the supercomputer manufacturers sell to Japan they rapidly purchased every supercomputer available. This was THE single greatest reason for U.S. downfall in quality edge. Had the government kept in place current export controls the Japanese car makers would be at least 10 YEARS behind us today. Thank your local congressman for selling out the American auto industry about 25 years ago, this is why Toyota is now the world’s biggest auto maker.
July 26th, 2008 at 8:53 pm
I am going for the long-winded explanation. First see this link on the EV-1.
http://avt.inl.gov/pdf/fsev/eva/ev1_eva.pdf
As the Volt’s batteries near the 35% SOC, the ECM (engine controller) will know it will soon be time to start the ICE. At this juncture, it will look at the vehicle’s power draw for the last few minutes, and determine what power to select for the ICE.
Looking at the EV-1 data, the driving cycle req’d an average power of 5.28 kW, the constant 45 mph req’d 5.81 kW, and the constant 60 mph req’d 10.28 kW. Obviously, faster and more aggressive driving would require even more power.
So now, based upon the last 3 to 5 minutes of power draw, the ECM will select a power setting for the ICE. This will be adjusted accordingly if average power consumption increases or decreases.
Now let’s look at the performance curve that I just posted for an aircraft diesel engine.
http://www.deltahawkengines.com/perfor01.shtml
Let’s assume that this is the curve for the 1.4 L ICE, only with some modification. Since this engine is much larger than the Volt’s ICE output, let’s just assume that the x-axis is kW times 2. In other words, the 100 hp point on this curve is actually 50 kW. For discussion purposes, I will say the the Volt’s ICE will operate at 3 distinct points, 16 kW, 32 kW, and 50 kW.
As battery SOC approaches 35%, If the ECM detects low power draw such as the urban cycle of less than 10 kW, it will select the 16 kW output. If we look at the engine curve, this would be most efficiently provided at 1500 rpm (0.43 BSFC, remember this is 32 hp on the curve). This provides power for the Volt’s driving cycle, and some power back to the battery pack (see curve from Lyle’s previous post).
Similarly, if the average power draw is above 16 kW, the ECM will call for a higher output of 32 kW. From the curve (64 hp) we see the best efficiency would be at about 1800 rpm (0.41 BSFC).
If the Volt is climbing a long steep grade (Rocky Mountain scenario) or traveling across Montana at a continuous 120 mph, the ECM will sense the need for maximum power, and the ICE will need to provide all 50 kW. From the curve (100 hp) we see the best point of operation is at 2200 rpm (0.425 BSFC).
Although this curve is not accurate for the 1.4 L, certainly GM will generate this performance curve in their new test facility. From this data, and the anticipated driving needs for the Volt, they can generate the load scenario and software to seamlessly integrate the ICE into the Volt’s operational scheme.
July 26th, 2008 at 9:44 pm
#53 Grizzly
#54 Bill R
OK, so if the engine is more powerful than it needs to be, then it could have a good brake-specific fuel consumption, but still not be very efficient for the car. Is this right?
In other words, does the brake-specific fuel consumption tell us anything specific about the Volt’s fuel economy?
The fact that the 1.4L NA weighs less than the 1.0L turbo is good news, but I’m still trying to figure out the fuel economy issue.
July 26th, 2008 at 10:00 pm
If this car makes it to production, I will buy it and this will be the first American car I have bought in 12 years.
GM do ya here me?
John in Texas
July 26th, 2008 at 10:02 pm
Dave G #57
“n other words, does the brake-specific fuel consumption tell us anything specific about the Volt’s fuel economy?”
*** *** ***
Dave,
Yes it does, I can’t tell you what the EPA figs will be, but this is very good news. What the brake-specific does essentially is allow you to target a specific engine power output needed and make a comparison. So for the Volt, the power needed or drawn from these engines to maintain the 30-35% SOC delivered by both the 3-bangerT and the 4-banger results in the 4-banger consuming less fuel. What I don’t know if this is across the board, or just steady state, but even if it’s the latter, it tells us that the 4-banger will get better HWY mileage than the 3.
July 26th, 2008 at 10:04 pm
Thanks for the info, BillR. Man, the EV1 could go over 220 miles at 45 miles/hr? That’s amazing!!! I read a New York Times article the other day that said the EV1 failed because the NiMH batteries could only take the car 70 miles.
Too bad the large format NiMH batteries are not allowed to be sold right now. GM sold the patent rights to Chevron’s Cobasys, who is currently sitting on them. When does the patent encumbrance expire???
By the way, I’m doing a conversion that will get about 40 miles per charge, and the total cost is around $1500. Not bad, considering the Volt’s all electric range will be 40 miles, and it’s cost will be like $40,000.
Don’t believe me? Check out my first youtube video on the subject. Search for MPaulHolmes.
July 26th, 2008 at 10:04 pm
Exp?eng
The gebset is to maintain the minimum SOC, not the max. The whole point is to fill it up with cheap electrons at HOME, not with petrol.
HTH,
Tag
July 26th, 2008 at 10:12 pm
That guy will not and cannot do a good job, so what do you expect from GM? The thing is so messy!
July 26th, 2008 at 10:24 pm
I wonder if I will have a Volt or CRZ the race is on.
July 26th, 2008 at 10:30 pm
Oh my gawd does that drivetrain look messy. Keep It Simple Stupid ! GM needs to get back to the basics. Put all the complexity in the software where it is hidden from the customer and make the driveline lean and mean.
July 26th, 2008 at 10:35 pm
I have an electric go-kart that has just 6 lead-acid batteries. It goes zoom zoom. How hard can this EV development really be. What is taking GM sooooo long. Build it already, while i’m still young.
July 26th, 2008 at 10:41 pm
#27 omegaman66
#28 Grizzly
I know what you mean; these people are so far beneath us. Maybe we should start our own elite blog.
July 26th, 2008 at 10:47 pm
52 >> I know of no “American” Big 3 vehicle that has an electric air conditioner compressor.
Really? That’s in interesting discovery. Last year, I thought I had come across mention that GM would use it for Two-Mode. If not, what the $*#@! were they thinking?
Having the A/C running with the engine off while waiting at a stoplight and while cruising in stealth is an upgrade (from my 2001 Prius to a 2004) that I totally love; MPG is definitely better… a benefit from taking advantage of the engine for efficient recharging opportunities.
July 26th, 2008 at 10:50 pm
#21
The question about the air conditioning seems important. GM said one of their first release areas will be FL. I live in FL. FL gets hot (today it was over 90° on the other side of my containment). If the little engine has to run all the time when the AC is on, that would kind of reduce the [insert current guess] all electric range to zero. That would make the Japanese “P car” a better deal. Since that doesn’t make sense, can I assume running the AC will just reduce the all electric range, but not eliminate it? Maybe I could still get 15-20 miles?
======================================
The Toyota’s / Lexus hybrid uses electric power steering and electric A/C so using the A/C will drain the battery faster and require the ICE to kick in sooner but you will have some battery miles before the ICE kicks in. Also keep in mind that the A/C compressor will cycle on and off so the compressor may only run for 20% to 30% of the time on warm days and maybe 70% to 90% of the time on real hot days. It also will depend on how cold you try to keep the interior of your car. I keep the A/C on my Lexus set to 78 degrees so the Compressor doesn’t cycle on too long
July 26th, 2008 at 11:25 pm
“In fact, GM would be smart to use one of their very best mufflers for the Volt. They should also put a bunch of soundproofing materials around the Volt to keep that IC engine sound and tire road noise out of the cabin of the Volt.”
I agree. As quiet as possible.
Someone brought up the CNN story about the kid hit with a bike.
I’m sorry, but your children should always be taught to look both ways before crossing the street (or riding their bike in the middle of it)
You may call me several bad names for this, but I say let something happen to them – then they’ll learn
No, I’m not a parent, it may seem harsh, but I think its the way things should be. Kids are spoiled these days, the best way to learn is to have something happen. If you see that lovely hot stove, and mom says “Don’t touch that, its hot.” and you touch it anyway, you learn INSTANTLY to never touch a hot stove again.
That being said, its VERY rare that your car will make NO noise whatsoever.
1) tires rolling on pavement make quite a bit of noise.. this prius must’ve been going like 1ft/hour or something.
2) I dunno about your roads, but ours are far from perfect. You’re gonna hit bumps/cracks and make sound.
3) if you’re rolling along and regen braking, it will make a humming noise (probably not loud, but definitely above ambient noise)
The ONLY legitimate claim is for the blind. Even then, you’d only be silent when going REALLY slow, so you have plenty of time to stop when they walk out in front of you.
Most blind people do not wonder out alone – if they do its either in small towns where its safer to walk alone, less traffic, and people know you, less likely to have an incident (this is why my aunt lives where she does)
or they live in large cities – every crosswalk in the city of Toronto has audible crosswalk sounds so you know when the way is (supposed to be) clear for you. If someone doesnt obey the lights, it doesnt matter what car they’re driving, you’re going to be hit anyways.
Begin the flaming now, if you wish.
July 26th, 2008 at 11:26 pm
ThombDhbomb #66
When people (or in this case probably one person under multi user names) intentionally post as though they haven’t even read the blog header, nor the previous one, you’ve pretty much got a trolling issue. Simple, not elite.
July 26th, 2008 at 11:31 pm
#37 “If they make electric power steering, electric-assist brakes, electric heat pumps, D-class stereo amps and all these other high-efficiency electric devices WHY are they not in every car made ???”
Well actually the Cobalt and HHR have had electric steering since they came out. The big two mode hybrids are using a new 42 volt system for the trucks. As far as brakes, that big old vacuum booster’s been gone for years. 4 wheel anti-locks have had electro-hydraulic pumps a long time. My 1988 Oldsmobile had fully electric brakes. The heat pump is interesting, remember a fully charged Volt will not run it’s ICE for 40 miles. So as you leave on 20 degree morning you will need some source of heat, not just air-conditioning. This is not an issue on the current parallel hybrids. I’m really hoping there will be a pre-warm/cool down mode while still plugged in at home. The high level Bose systems are now using digital amps, really NOT a priority for me.
July 26th, 2008 at 11:39 pm
Oh, and i forgot to mention – if you take a step back and picture the engine change – it is no big deal at all.
The actual engine displacement itself is the same volume as 4 cans of pop. 4 cans.
The first proposed engine was 3 cans.
Its all the extra “crap” around the engine that takes up the most space, but unfortunately, it’s needed.
Versus electric.. you need uhhh a motor, and a controller. Done
Ok, and an inverter too, if your batteries arent wired in series/parallel combinations to provide the voltage you need.
July 26th, 2008 at 11:47 pm
The Toyota / Lexus hybrid` needs electric steering and`A/C bucausetere`are many times`when the`ICE`is totally shut down. Having the`A/C turn off would beanoying, but having the`power steering shout off while coasting a long winding hill could spell disaster. It would be the same problem with the volt.
electric A/C is better for maany reasons, one reason is the A/C compressor spins at a constant speed, while a engine driven one is always speeding up and slowing down
July 27th, 2008 at 12:09 am
Lyle – terrific post.
#36 and #69, “use one of their very best mufflers for the Volt”
If they choose to, because the ICE will be essentially constant RPM, it should be possible to finely tune both the intake and exhaust plumbing (manifolds, etc. – much more than just the muffler) to keep the sound either as quiet, or as throaty, as they like. Actually, I wouldn’t mind some sound outside the cabin. If you’ve ever been jumped by a Prius in a parking lot while you’re walking, you know what I mean.
Regarding the original post: the choice of the engine almost certainly depended on more than just an optimization for the Volt itself. The 4 cylinder likely can have a home in some other GM vehicle (even not an E-REV), but the 3 cylinder is less likely to find an alternative home, I would think. Thus, the 4 cylinder makes sense for the economies of scale.
July 27th, 2008 at 12:11 am
Has anyone looked at the Everspring Lithium batteries, Far cheaper than the 123, Valence and the rest. These batteries are around the cost comp. to lead acid! I Seems like the way to bring the cost of the Volt WAY down..
July 27th, 2008 at 12:48 am
It will be interesting to see how the GM designers handle heating and defrosting demands. In the 1990’s EVermont added kerosene/diesel fired heaters for warm-air defrosting and cabin heat plus electrically-heated passenger seats to its battery electric cars operated in Vermont cold weather.
July 27th, 2008 at 12:59 am
As long as it isn’t using one of those crazy hydrogen fuel cell schemes, I am fine with this.
July 27th, 2008 at 1:39 am
hi ive been giving the whole.. user selected modes a thought
and i came to the conculsions that a few here have had too
in an earlier post nasa man brought it to my attention someone said
a longer ranged mode or steep grade mode is a good idea i agree
someone mentioned here a mode inwhich it uses all the power faster .. like a racing or Emergency mode? ala to save ur dieing loved one or to get ur wife whos preggy with the neighbors baby to the hospital faster .
and the normal standard mode that the volt comes shiped in..
ultility mode its good for average days n ok for longer hauls.
for everyone that dont know how to interprete this post.. due to my piss poor grammar and spelling
1. econo mode conserving as much as possible .. maybe its a city mode aka traffic or sitting and waiting alot..
2. long haul.distance mode.maybe use the ice as the volt is discharging.. in the lowest mode to conserve the battery longer .
heavy loads or racing emergency or steep hill mode. to use as much possible availible energy as possible to get where ur goin or faster.( note go the speed limit! lol unless its an emergency) aka dieing is a good one..
3. normal or standard/ utility mode .. genral setting it would discharge as normal then the ice takes over as it discharges to 30/35 % ,,,,,,,,also the mode it comes shiped in
which all makes sense
id have a big button on the steering wheel maybe a text or sound message
u are now in MODE :Economy
U now r in mode: heavy loads/ steep hills
July 27th, 2008 at 2:00 am
Did someone say a normally aspirated ICE? As in carburetor? Hmmm where are those 4bbl Hollys I used to put on the ol 283? Always remember the sucking sound when you tromped on it. But since this is supposed to be a “lets save a lotta gas” kinda car, so why not fuel injected? Understand that’s way more efficient.
Yes… a 4banger ICE running at 1800rpm makes way more sense than a 3banger would up like a $2 wrist-watch at 3k. I see way less maintenance and lower engine wear resulting in longer engine life before TBO.
Cute… a Hobbs hour meter rather than an odometer? …. sounds like the days of my trusty C-150. The Regulators are gonna freak… they’ll never be able to wrap their minds around the concept.
Rock on GM…
July 27th, 2008 at 2:15 am
john1701a @ # 67,
“Really? That’s in interesting discovery. Last year, I thought I had come across mention that GM would use it for Two-Mode. If not, what the $*#@! were they thinking?”
————————————————————————
I checked and the two-mode hybrids DO have electric compressors. It was September when I was looking at the hybrid vehicles and the Tahoe etc. had not gone on sale at that time. Besides, $50,000+ vehicles were not what I was interested in, heh. Surely Ford will put an electric compressor on the 2009 Escape hybrid, but I have seen nothing from Ford confirming it so far.
July 27th, 2008 at 4:02 am
never mind the AC. it wont significantly reduce the range.
as for engine choice, I guess for ‘americans’ 1.4L is as humble as you could hope for but if it was me I would at least aim for a much smaller engine like a 2cyl 0.6L engine to keep the weight/cost/volume low. you don’t need 50kW continuous power in the range extender. that’s US insanity. the lighter, the faster.
you don’t cater to idiots who think you have to be able to pull a 15ton trailer up a steep mountain at 200km/h. just make it clear that the range extender is for distance cruising only and not nascar racing. the range extender should not be fun, it should be awkward.
and I would go much further. I would look into making a magnetically assisted crankless engine/generator that is just a linear or rocking cylinder that instead of a crank has magnetic actuation for motion and power generation. that way the cycle can be digitally controlled for optimal efficiency with very few mowing parts.
July 27th, 2008 at 5:11 am
You know I like American cars. Theres nothing wrong with them. All cars break down. You cant expect red carpet treatment on a tin foil budget. Toyota Prius drivers are just greenie snobs. The break down a lot too I’m sure. The environment will take care of itself so you don’t have to worry about pollution especilly with medical insurance and a good job. Now the Volt is really cool because you can stick it to the oil companies AND the Prius people. I like that.
Toyota people make me sick. They shove theyre hybrids in peoples faces, park them in front of our houses and hurt out jobs. They act like repairing a car is too good for them. They shouldn’t have to repair cars all the time. But I guess things change if you want it or not. The Volt is going to be good because it’s a
good ole U S of A car not some tin can Prius.
The only thing I don’t like about these cars is they hurt US soldiers. They need jobs and if youdont need oil well…you get the picture.
If God wanted us to drive a Prius He would have given us a signal like put an assembly plant in America to build them. But thats not what God did. God put the VOLT in HAMTRAMAK MICHIGAN in the USA. Now THATS a SIGN.
July 27th, 2008 at 5:18 am
ah grizz my old friend, i only get on here every few months now, but i see ur still dealin’ with trolls, lol…
fubar thanks for the tip on the batteries. i will check it out. i use an electric scooter for trips to the deli and such. gets the equivalent of app 500 mpg using lead acid batts. would love to pick up some lithiums at a decent price!
July 27th, 2008 at 6:29 am
#81 Dan Frederiksen
You don’t understand the purpose for the Volt. It is not being made to be a very efficient super maxed out high mpg vehicle. YES the vehicle will get anywhere from ~50 mpg on up to infinity. But bumping that up with tweaks and such is not a goal yet.
The Volt will be the first of its kind vehicle that is designed to be a jack or all trades that perfoms without sacrifices to people that will NEVER visit a website like this. It is designed to be an electric car that a person can get in and drive just like they drive now without quirks such as no AC not heater, manually doing anything to swap from battery power to ICE generated electricity, no range anxiety, no shortlived batteries. This car regardless of how good its gas mileage is has to first and formost perform without major mechanical issues because it is designed to PROVE this technology to the everyday person.
alay all the fears of EV short range fears, remove slow acceleration beliefs, remove dead battery issues.
With ANY new technology the first is never going to be the best. After the volt gets up and running then you will start to see all these new fangled high efficiency ICE engines etc etc etc.
July 27th, 2008 at 6:30 am
If you don’t like the 1.4L and are totally against it, then don’t buy the car. It’s as simple as that. I will be glad to step up and take yours. I wouldn’t mind increasing my chances of getting one sooner rather then later anyway.
July 27th, 2008 at 6:33 am
I am confused.
For weeks we have been asking GM to make some firm decisions about the Volt, and to let us know what they are.
They make a pretty big decision, and tell us, but then many here start screaming that it is a bad decision.
Since I am not a car designer or an engineer, I would have to think that the designers at GM know better what is the best choice for this application.
But make no mistake, there will sometimes be compromises made for corporate reasons that have nothing to do with the car. If this engine is already in production, reliable, and does not require any new inital investment, that may override a technically superior engine that would not be available in time for production, or increase the final cost even further.
We can’t have it both ways. You can’t have the best of the best in every single detail, and have the car sell in the less than $40K price point (I am still hoping it ends up in the mid $30K range!). GM could produce an E-REV Rolls Royce, but then it would cost so much that almost none of us could afford it, and that defeats the entire idea of this project, don’t you think?
JMHO
July 27th, 2008 at 6:37 am
Proud American wrote “because you can stick it to the oil companies ”
Proud american just a question. What have the oil companies ever done to you other than provide you with a product that has to be drilled out of the ground transported refined shipped to the gas station for less than the price it cost to get milk from a cow?
July 27th, 2008 at 6:41 am
To Jim I. What you fail to understand is that the majority of the people here are way way smarter than the people that work for GM. GM is in bad finacial shape because they hire idiots instead of getting rid of all there current engineers and just hiring the people that post here.
July 27th, 2008 at 6:41 am
“for everyone that dont know how to interprete this post.. due to my piss poor grammar and spelling”
************************************************************
You are probably an intelligent person but got caught in the language teenagers use on cell phones. My advice is: stop using those shortcuts and spell the complete words and use the spell checker. Later in life, you’ll be thankful you did.
July 27th, 2008 at 6:55 am
DonC@2
“GM engineering is not usually the issue. The issue is whether GM can build the vehicle with reasonably few manufacturing defects.”
******************************************************
I can tell you that GM’s manufacturing defects are as few as any other car manufacturers. GM offers a 5 year and 1000,000 mile warranty. What does Toyota offer?
July 27th, 2008 at 7:00 am
A really good informative post, Lyle. I am really happy today.
And folks, its not the Volt drive train in the picture, but the Volt ICE undergoing testing.
July 27th, 2008 at 7:08 am
#79 Richard
Any engine sucking in its own fuel and air without help of turbo or super charger is normally aspirated.
Lyle,
Great post this is good news instead of we are thinking of …. It is this is what it will be…
Good to hear the volt’s drivetrain is taking center stage at GM’s new advanced powertrain engineering center.
This makes Voltik smile, looks like my research and dyno runs on the 1L turbo and 1.4L na were right on.
1.4L pulled the load better and took less fuel per hour doing it.
GOOOOOOOOO GM
GOOOOOOOOOOOOOOOO VOLT
July 27th, 2008 at 7:14 am
#87 omegaman66
“Proud american just a question. What have the oil companies ever done to you other than provide you with a product that has to be drilled out of the ground transported refined shipped to the gas station for less than the price it cost to get milk from a cow?”
1) Oil companies receive over 19 billion (Not million) dollars of tax subsidies from the federal government. This is corporate welfare. The 19 billion should be taken away from the oil companies and given back to the taxpayers. The oil companies do not need any subsidies with their record profits!
2)The American military right now as I am typing this is spending over 100 billion in the middle east protecting the oil lanes for the oil companies.
3)Gulf war 1 (Kuwait) and Gulf war 2 (Iraq) had everything to do with oil.
4) American soldiers are getting killed in this war for oil. Can you name one soldier killed “to get milk from a cow?”.
So Mr. omegaman66, if you factor in all the above, the true price of oil would be over $300.00 a barrel, and at the pump above $10.00 per gallon.
Antranig
July 27th, 2008 at 7:25 am
Keep up the enthusiasm. This is all good information. The oil Companies are starting to run scared. Build them and they will sell, as long as the price is right!
July 27th, 2008 at 7:27 am
#36
How’s about a collision radar with an “auto honk” feature to warn the mentally defective or vision impaired?
Something similar to what’s installed on the rear bumper of many large trucks and SUVs except, more powerful and tuned for small objects like people, bicycles ect…
July 27th, 2008 at 7:35 am
#42 Dave G asked:
“For one thing, per Nitz, “the 1.4L NA four has better brake-specific fuel consumption than the 1.0L turbo when used in steady state mode, as it will be in the Volt application.”
————————————————————————————–
OK, can someone translate this for me? I assume NA is non-aspirated, but what exactly is “brake-specific fuel consumption”?”
This means that the 1.4L will use less fuel than the 1.0L turbo.
“Brake specific fuel consumption” (bsfc) measures the energy efficiency of the engine. In the US, we often use “lb/hp-hr” to measure bsfc.
The fuel is weighed to determine its potential energy supplied to the engine. This is more accurate than measuring its volume, since the density (lb/gal) of the fuel varies with temperature. A “brake” (dynamometer) is used to meaure the engine output torque, which is used with the engine RPM to calculate the output power. Finally the power is multiplied by the time period to consume the weighed amount of fuel to get the energy output at the engine flywheel.
The ratio of potential (chemical) energy provided to the engine to the energy output at the flywheel (lb/hp-hr) is a measure of the overall engine efficiency. It is more widely used than calculating the efficiecny in %.
BSFC is about energy, not power. Some of the other posts do not make this clear.
The 1.0 turbo probably would have difficiulity running a high compression ratio Miller/Atkinson cycle to maximise bsfc like the prius does with its 1.5L, 13:1 compression, NA engine. This 1.4L NA engine should help make the Volt compete with the next gen Prius in mpg.
July 27th, 2008 at 7:40 am
follow up to #13 – “Nitz also states that GM has refined the charging window of the pack as 35% to 85%, whereas previously GM had said it would be 30% to 80%. He does say though that the battery could be discharged below 35% if it has to on rare occasions, but that when steady state resumes, the battery WILL RECHARGE as the engine then produces more output than the car requires at that time”.
—————————————————————-
Lyle, no one has yet confirmed or denied whether GM has changed it’s mind about using the ICE generated power to recharge the Volt battery at a safe rate. Perhaps you could ask the GM engineers whether the above comment from the acticle is true or not. This is a huge issue to me…Thanks.
To me, it makes absolutely no sense to waste all of the excess ICE generated power. On level ground, the excess power could be used to partially recharge the battery at a safe rate. The battery could be half charged by the time you arrive at your hotel. That’s extra gas-free miles the next morning, which would otherwise be lost. That makes a LOT of sense to me.
July 27th, 2008 at 7:51 am
I take the last paragraph to say they do plan on using the extra from the ice to charge the battery…
” Nitz also states that GM has refined the charging window of the pack as 35% to 85%, whereas previously GM had said it would be 30% to 80%. He does say though that the battery could be discharged below 35% if it has to on rare occasions, but that when steady state resumes, the battery will recharge as the engine then produces more output than the car requires at that time.”
GOOOOOOOOOOOOOOOOOO Volt
July 27th, 2008 at 7:53 am
OFF TOPIC:
Lyle,
You need to put a countdown clock on the home page to the unveiling of the Volt. Then you can reset it to the production release date, etc.
Great website. I check it everyday.
July 27th, 2008 at 7:53 am
#61 Tag wrote:
“Exp?eng
The gebset is to maintain the minimum SOC, not the max. The whole point is to fill it up with cheap electrons at HOME, not with petrol.”
I know this detail quite well.
Please re-read what I wrote @ #22.
That posting was another attempt to remind people of the technical facts that GM revealed many months ago.
A few uninformed people have been chiming in at times and stating that the ICE will “charge up the pack” when it runs. In their opinion, anything less is a complete waste.
These folks are the same ones that want GM to produce a “battery only version” of the Volt. They also argue that any ICE equipped Volt should have the displacement of a Weed-Eater.
They don’t understand the engineering of the Volt.
July 27th, 2008 at 8:24 am
# 96 GPS
NA is normally aspirated see post #92 for explanation.
In this case as with my virtual dyno runs Brake-specific fuel consumption refers to engine running at a given rpm pulling a torque load specific to the task at hand (ie the load of the alternator) not what the engine would require at full load.
GOOOOOOOOOOOO GM
GOOOOOOOOOOOOOOO VOLT
July 27th, 2008 at 8:29 am
This statement is troubling:
“Nitz goes on to say the generator produces 50 kw, whereas the electric motor produces 100 kw, and assures us that the “vehicle will never use more than 50kW on a continuous basis,” and says “zero to sixty, passing maneuvers, you’ll be fine, the ability to actually use more than about 50kW doesn’t exist very frequently.”
I personally do not like the idea of limiting the electric motor to 50 kW. Actually, I honestly believe that we will will not like anything less than 90 kW. Time will tell though and I hope these GM engineers are correct, otherwise we may be disappointed with the Volt’s performance with the genset running.
July 27th, 2008 at 8:57 am
I’m ready with a deposit. I don’t mind waiting more years untill i get one. I’ll just keep my 11 year old ice running untill i can finally junk it for a VOLT. Kind-of patiently waiting.
July 27th, 2008 at 9:08 am
GM has 132 miles of test track at the Milford proving grounds alone…
Testing for range and acceleration is will be the easy part of developing the VOLT.
The hard part is getting the costs in place… developing the unique parts needed and putting them all together on time. Unlike Japanese companies who just go and get free money from the Japanese government.. GM has to rely on profits and take risks.
July 27th, 2008 at 9:08 am
Thomb@66
You know that Omega and Grizzly are members in good standing (as are you). All of us break the PDNFTT principal (as do you). Just my opinion, but “elitist” seems a bit over the top. Please don’t start a tempest in a teapot about my use of the term “members in good standing “. You know what I mean.
JMO,
Be well,
Tag
July 27th, 2008 at 9:15 am
Exp_eng
I re-read #22 and it’s the
“I still have to believe the ICE / Generator WILL NEVER BE ALLOWED TO RECHARGE THE PACK TO 85% (the new “FULL” point).”
That sounded to me that the genset was recharging the Battery – just never to the max. I hope you understand how I was confused, because I can still read that as correct or incorrect.
My bad. Thanks for the clarification.
Be well,
Tag
July 27th, 2008 at 9:21 am
Just to clarify as there seems to be some confusion on the subject.
The demand in electricity of the engine and all accessories will vary. From sitting at a stop sign in mild weather during the daytime to accelerating up a hill in the cold with heater running at night. The varience in power needed between these two scenarios is extreme.
The ICE will either run at a steady state or at a small rpm range. It will not run in a range from 500rpm to 6000rpm.
What this means is that at times the ICE will be producing more energy than is being consumed. You have a choice either use this energy to recharge the battery or waste it. Obviously wasting it is not an option that make sense. So this extra energy will charge the battery. Once the battery SOC reaches say 40%, the ICE will shut down and the battery power will power the electric motor until 35% is reached.
This and the fact that possibly the ICE won’t alway supply enough juice possibly requiring the batteries to drop down below 35% will result in the SOC not staying at a steady 35% with absolutely no fluctuations.
July 27th, 2008 at 9:26 am
Lyle’s post says in one place
“Since the four cylinder engine is also longer, GM has had to reconfigure the packaging somewhat to make it fit, which as per Nitz is ‘turning out nice.’ ”
Not much detail here, but I wonder what “reconfigure the packaging” implies. I hope it does not imply some awkward or crowded engine access, as it is hard to live with cars like that.
Thinking positively, “turning out nice” sounds good.
July 27th, 2008 at 9:34 am
Antranig Van wrote:
“#87 omegaman66
1) Oil companies receive over 19 billion (Not million) dollars of tax subsidies from the federal government. This is corporate welfare. The 19 billion should be taken away from the oil companies and given back to the taxpayers. The oil companies do not need any subsidies with their record profits!
2)The American military right now as I am typing this is spending over 100 billion in the middle east protecting the oil lanes for the oil companies.
3)Gulf war 1 (Kuwait) and Gulf war 2 (Iraq) had everything to do with oil.
4) American soldiers are getting killed in this war for oil. Can you name one soldier killed “to get milk from a cow?”.
So Mr. omegaman66, if you factor in all the above, the true price of oil would be over $300.00 a barrel, and at the pump above $10.00 per gallon.”
******************************
1. The oil companies have plants over seas and over here. Removing tax breaks means more of those jobs would transfer overseas. When a company is expanding or opening a new line they weigh the cost from multiple locations. Also those tax break rules that the media wants you to think only apply to oil companies actually apply to many other businesses as well. But they don’t car about hurting the economy or causeing those oil and non-oil jobs to disappear. They just want to make political points.
2 thru 4. The oil companies have absolutely nothing to do with American foriegn policy. Chevron/Exxon/Texaco etc do not decide if we go to war or not. I Suppose we are in Afghanistan for the oil too. Second gulf war was not about oil. It was about WMD of which Iraq had over 500 tons of Yellow Cake Uranium. Which everyone in congress knew about all the while they were yelling about there not being any WMD’s in Iraq. The news was kept from the public to make the transfer of it to Canada safer from terrorist until it was all moved.
Takes a pretty scummy person to make political hay out of an issue all the while knowing that the other side can’t go public with the proof to show there was WMD.
July 27th, 2008 at 9:37 am
Tag,
No problem.
The Engineering Tech / Instructor in me is always interested in the details. Whether an expert or newbie, I want everyone to appreciate and understand the Volt engineering. It’s Simply Brilliant.
Lyle, could you please put the “VoltChart” on the Home Page ?
http://www.gm-volt.com/i/voltchart.jpg
Perhaps GM could provide Lyle with a newer / nicer version.
That chart tells a lot of the story.
My Best Regards To You Tag
July 27th, 2008 at 9:40 am
exp-eng
Thanks.
If you use a real computer (not a Mac) you can right-click and save that chart to your computer.
Putting it on the home page is also a great idea.
Be well,
Tag
July 27th, 2008 at 9:45 am
#97 The Grump says: “To me, it makes absolutely no sense to waste all of the excess ICE generated power. On level ground, the excess power could be used to partially recharge the battery at a safe rate. The battery could be half charged by the time you arrive at your hotel. That’s extra gas-free miles the next morning, which would otherwise be lost.”
————————————————————————————–
The ICE will not have excess generated power. GM has already stated that the Volt will vary the ICE’s power output to match the average power requirements of the vehicle, so as to keep the battery at 30%. See here for details:
http://gm-volt.com/2007/08/29/latest-chevy-volt-battery-pack-and-generator-details-and-clarifications/
This latest info from Larry Nitz revises battery’s usable range from 30-80% to 35-85%, but the basic operation remains the same.
Now some people have questioned whether the gas engine will be constant RPM. They have noted that constant RPM engines can indeed vary their output. But after the information here from Larry Nitz, it seems more likely that the ICE will be variable RPM.
From the article: ‘Also Nitz claims the four cylinder engine will provide for a smoother transition from EV to range extension saying “the objective is to keep the engine off and when the engine comes on, you don’t want to know it’s on.” ‘
So I interpret this as variable RPM, since constant RPM would be considerably louder at low speeds.
To be clear, I believe the battery can take a charge fairly quickly from the ICE. This would be necessary to recharge the battery back to 35% after a long steep uphill climb. But I see no reason for the Volt’s control code to ask the ICE to charge the battery beyond 35%. The idea of the Volt is to use as little gas as possible. If you are near your driveway, you don’t want the ICE using up more gas to charge the battery.
July 27th, 2008 at 9:47 am
I’ll try to answer some of the questions I saw. NA means Normally Aspirated that means no super or turbo charger. Break specific Fuel Consumption. The amount of fuel to produce one unit of power over a fixed period of time. In the US it is stated as pounds of fuel per horsepower per hour. .5 pounds of fuel per horsepower hour is a common result for a constant speed engine. Must internal combustion engines produce their best rates at about 85% of their maximum power at any given rotational speed, RPM. When accelerating using an electric motor the amount of electricity used is the same whether you accelerate slow or fast as long as you do not spin the tires. This is why they have a 100KW electric motor for fast acceleration. By running the ICE at a constant rpm they can always get the best fuel mileage. By starting the recharge of the battery at 85% charge they can get more cycles out of them than if they discharged them more. I do not know about the batteries GM is using but with lead acid batteries the difference can be 10 times more life at low discharge before recharge vs high discharge. I’m a retired engineer with an interest in electric and hybrid cars. What can you do to save fuel now? Drive less by combining trips. Car pool. The other things like tire pressure save a little along with good driving habits but these savings are minor when compared to combining trips so sometimes you do not drive at all. Plan each trip short or long. Ask other members of the house hold what they need before you drive. Make up a menu so you do not have to go to the market for one item. Where possible use public transportation. When it is time for a new vehicle get one with better economy than the old one. Remember that Suburban you trade in will be bought and driven by someone else. So unless it is ready for salvage there will be no national fuel savings by trading in a usable car.
July 27th, 2008 at 9:53 am
Tag wrote:
“If you use a real computer (not a Mac)…”
That is sooo funny to me !
I have never owned a Mac but I once worked for a company catering to Mac folks (producing wireless stuff before Wi-Fi).
That brief exposure to Mac’s was my vaccination !
July 27th, 2008 at 9:58 am
Exp_eng
I was just stirring the pot. My one daughter went to the Dark Side (a Fisher-Price laptop), but the other daughter has stayed true to the platform on which she was raised.
It’s bit like politics and religion though, best not debated on a blog.
Be well,
Tag
July 27th, 2008 at 10:00 am
112 >> The ICE will not have excess generated power. GM has already stated that the Volt will vary the ICE’s power output to match the average power requirements of the vehicle, so as to keep the battery at 30%.
On paper differs from reality; there’s no such thing as constant driving. Road conditions vary every few seconds. The frequency & degree of those adjustments to engine operation will be limited to some degree.
That’s the beauty of having a battery-pack. Energy that could otherwise be wasted is captured. Traditional vehicles simply are not designed to take advantage of those plentiful small efficiency gain opportunities.
July 27th, 2008 at 10:02 am
#107 omegaman66 says: “The ICE will either run at a steady state or at a small rpm range. It will not run in a range from 500rpm to 6000rpm.”
————————————————————————————–
What is your source of information for this?
I interpret Larry NIitz’s phrase “steady state” as the ICE RPMs perfectly matching the demands of the car, so that the battery is neither charging nor discharging.
When the car accelerates or goes up a steep hill, it is no longer in steady state, as the battery will discharge. Similarly, if the ICE is running increased RPMs to charge the battery back to 35%, it is not in steady state.
From the article:
“He does say though that the battery could be discharged below 35% if it has to on rare occasions, but that when steady state resumes, the battery will recharge as the engine then produces more output than the car requires at that time.”
But this is still ambiguous.
Lyle,
Could you ask GM if the ICE is constant or variable RPM?
July 27th, 2008 at 10:07 am
If you’re worried about that low-sounding 50 kW rating for the electric motor don’t forget: electric motors have a lot of torque, and they have it right away starting from a dead stop.
Did you ever get on an electric city bus and have to suddenly grab on when the driver took off from a stop?
Diesels, like electric motors, have a lot of torque: Farm tractors have a ton of torque but not much horsepower (Watts). A 100 hp car isn’t that much, but a 100 hp tractor is darn big.
speaking of Watts as a power measurement (but backwards): what is the horsepower of a 13-watt bulb?
About air-conditioning, the Prius is better insulated than the average car and also Did you ever notice how instantly your car gets hot on a warm day going from shade to sun, or even the sun comes out from behind a cloud? I don’t want to drive the price of the Volt up too much, but any heat-blocking glass GM can use might pay off. Block the infra-red and UV.
Torque X HP questions: Could a weird engine generate some HP but no torque? or vice versa? Can a drive shaft deliver torque w/o delivering horsepower? (that’s rhetorical! don’t answer here! let’s stay on topic!)
and FINELY! omegaman66, yes the oil companies have been distorting tax policy for decades: If your a coffee shop and you open a second location that fails, does the Treasury re-imburse your expenses?
I used to think energy companies were OK and even somewhat magical drilling so deep and all … then I ended up living in an area with natural gas wells. Now I perceive energy cos. as 1) a file cabinet full of leases 2) tax lawyer 3) lobbyist. They hire contractors to do the actual work in order to avoid expenses when there’s a downturn.
July 27th, 2008 at 10:08 am
From what is told the 1.4 makes sense.
I realize this will be an Ideal communter car but can I take one of these vehicles on a cross country trip? Will I be straining the motors or battery by driving across the country or is the use of the ICE only supposed to be to “get you home” or across town or the like. In other words – will prolonged highway driving be bad for vehicle? I know they gave us a long range but can we use that day after day for say 2 weeks for a vacation?
July 27th, 2008 at 10:11 am
#116 john1701a says: “On paper differs from reality; there’s no such thing as constant driving. Road conditions vary every few seconds. The frequency & degree of those adjustments to engine operation will be limited to some degree.
That’s the beauty of having a battery-pack. Energy that could otherwise be wasted is captured. Traditional vehicles simply are not designed to take advantage of those plentiful small efficiency gain opportunities.”
————————————————————————————–
Yes, I agree.
My point was that #97 Grump’s assumption that the ICE is somehow wasting energy that could be used to charge the battery up to 50% isn’t quite right.
The ICE will vary it’s output to meet average demands, but peak demands (accelerating or driving up a steep hill) will require some charging and discharging of the battery.
July 27th, 2008 at 10:15 am
#118 I. Ronnickly says “If you’re worried about that low-sounding 50 kW rating for the electric motor don’t forget…”
————————————————————————————–
The 50kW rating is for the ICE and generator. The electric motor is 100kW.
From the article:
“Nitz goes on to say the generator produces 50 kw, whereas the electric motor produces 100 kw, …”
By the way, both of these numbers are down from what GM has stated previously. It used to 53kW for the ICE/generator and 120kW for the electric motor.
July 27th, 2008 at 10:16 am
It would be nice if you could have a variable state of charge (SOC). If you are commuting back and forth to work you want the batteries at a low state of charge when you get home so you can charge them up on clean cheap electricity. If you are on a longer trip the ICE could keep the SOC higher so you have more reserve power for hills and acceleration. Maybe they could tie your navigator in so that when you program in “Home” it will get you there with a low SOC.
July 27th, 2008 at 10:22 am
#113 Luther Browning says: “Most internal combustion engines produce their best rates at about 85% of their maximum power at any given rotational speed, RPM. When accelerating using an electric motor the amount of electricity used is the same whether you accelerate slow or fast as long as you do not spin the tires. This is why they have a 100KW electric motor for fast acceleration. By running the ICE at a constant rpm they can always get the best fuel mileage.”
————————————————————————————–
GM stated last summer that the gas engine will be variable RPM.
http://gm-volt.com/2007/08/29/latest-chevy-volt-battery-pack-and-generator-details-and-clarifications/
What made you think it was constant RPM?
July 27th, 2008 at 10:23 am
Lyle,
Could you ask GM if the ICE is constant or variable RPM?
July 27th, 2008 at 10:42 am
#118 13 watts = .0174 hp = very tired horse
July 27th, 2008 at 10:42 am
People who are rending garments and tearing at their hair over Nitz saying “the generator produces 50 kw, whereas the electric motor produces 100 kw” when previously they heard that the generator and motor specs were more powerful — just chalk that up to a middle-manager or exec being imprecise.
July 27th, 2008 at 10:44 am
I am confused. Is the engine going to “generate” energy to power the drive motors and provide a charge to the batteries, or just provide energy to the batteries? Would it not make sense to have the generator provide the energy to the drive train AND recharge the batteries when they get to the 30% capacity level?
July 27th, 2008 at 10:46 am
RamZ,
(I’m tagging along on your post #122)
If your NAV system has a topographical map with altitude and route info in it, then the ICE could predictively turn on to raise the SOC (state of charge) to its maximum allowed (85%) in anticipation of a long climb.
and also to delete a routine turning-on of the ICE in anticipation of a long descent just ahead. The long descent will recharge your battery for free!
July 27th, 2008 at 10:49 am
#96 GSP says: ““Brake specific fuel consumption” (bsfc) measures the energy efficiency of the engine. In the US, we often use “lb/hp-hr” to measure bsfc.”
————————————————————————————–
Thanks for the explanation.
But what if the engine were oversized for the vehicle? A larger engine with more displacement would have more power, so the BSFC could be better (i.e. lower lb/hp-hr ratio), but this could actually make the fuel efficiency for the target vehcile worse.
Taking it to the extreme, If I had a very powerful V8 that was relativly fuel efficient for it’s power, it could have a very good BSFC.
So, without knowing whether the 1.4L NA is oversized for the Volt, and only knowing that it has a better BFSC than the 1.0L turbo, can we say anything for sure about the relative fuel efficiency?
Am I missing something here?
July 27th, 2008 at 10:49 am
You know, it will be kinda weird to stomp the pedal, hear the ICE wind up and off you go…knowing the electric motor is actually doing the work. I guess Flow Master will still have a market! Just kidding but you know people will do it…..
I wonder how they will deal with getting the cat lit-off to manage emissions. Maybe the ICE will run in the warm up cycle and that ok with emissions.
July 27th, 2008 at 10:52 am
#123 Dave G
Thanks for reminding us of the earlier post and graph. That graph seems a bit different from the more recent one (@110 by exp_engng), which clearly shows some peaks and valleys after the ICE comes on.
That leaves the constant or variable issue still a bit diffuse. Of course, “constant” with the choice of a few different settings becomes similar to “variable”, so maybe the answer is “neither”.
On the other hand, maybe GM engineers still are working out these details. I doubt that most owners are going to care much, if the system works smoothly.
July 27th, 2008 at 10:53 am
I remember when the Volt was going to be a $20k car..I want one when they arrive. But over the last year the price has almost doubled.
I want to help our country get away from oil dependence but it will not be economically possible for me to do so with the cost. I have always been an American car owner, specifically Ford. The Volt had me look and consider GM. With the skyrocketing price of the Volt, the Toyota Prius is more of what I can afford and still use less oil/gasoline.
I am still hoping the Volt will be available to me and my income. I am happy that GM is working on helping us get rid of the oil/gasoline dependence.
I still have my fingers crossed, and one last thing, “akojim” is bringing up a lot of questions and comments that are in my mind. The $18k price is a dream (but a nice one!) and the electric motor range here in Ohio will be interesting. Hot/humid summers needed air, frigid cold winters needing heat. The electric mileage would be so short it would not be worth using.
July 27th, 2008 at 10:57 am
#129 Dave G notes “Taking it to the extreme, If I had a very powerful V8 that was relativly fuel efficient for it’s power, it could have a very good BSFC.”
I want the powerful V8 for the Volt. Why just half a V8?
With the V8, I can be Clark Kent (quiet, all electric) or Superman (turn on the V8). What a car! [I'll just need a drive-through telephone booth.]
July 27th, 2008 at 10:58 am
#127 PJ asks: “I am confused. Is the engine going to “generate” energy to power the drive motors and provide a charge to the batteries, or just provide energy to the batteries? Would it not make sense to have the generator provide the energy to the drive train AND recharge the batteries when they get to the 30% capacity level?”
————————————————————————————–
The aim of the Volt design is to have the gas engine maintain the battery’s minimum charge level, now specified at 35%.
However, when accelerating hard or driving up a steep hill, the electric motor and remaining batteries provide the peak horsepower, so the batteries can occaisiaonally drain significanly below 35%. In the case, the gas engine does charge the battery back up to around 35%.
But to be clear, the gas engine never charges the batteries significanly beyond 35%.
July 27th, 2008 at 10:59 am
Are people really comfortable with that $40,000 hypothetical MSRP?
The Toyota Prius is a category-killer that you want to unseat. The 2008 model with the highest MSRP is $23,770. Elegant engineering, serial vs parallel hybrid, and nerdy design details has a worldwide market of … this blog thread’s posters. What is the extra $16,000 buying you that the Prius doesn’t have?
I hope that the $40k is merely ‘managing expectations’.
July 27th, 2008 at 11:06 am
Thanks for the info Lyle. Good post. It sounds like GM is serious about building this thing. We’ll have to see whether or not they can sell it at a price most people can afford before we can say if the Volt lives up to it’s full potential. America and the world desperately need affordable plug-in hybrids. It would really help reduce our dependance on foreign oil if we could get enough people driving Volts- but for that to happen, it needs to be a 20K car, not a 40K car.
I look forward to seeing how the Volt develops over the next few years. It sounds like I wont be able to afford one at first- and maybe never- unless the costs come down signifigantly. I currently drive a Hyundai, and while I get better mileage than a lot of folks, I am still irritated with 4.00/gallon gas, and I want an affordable alternative. While I am excited about the Volt’s technology and potential, I am also depressed about the price.
My Hyundai is on it’s last legs, and I was out browsing for a cheap new vehicle yesterday. Nothing that drives on 4 wheels particularly interested me or excited me in the 15K price range, so I found myself at the local Ducati dealership seriously thinking about getting a new yellow Ducati 1098. MSRP of 15,995.00 and pretty good MPG I think. That should tide me over until the Volt comes into my price range in a few years ( if it is ever going to do that ).
Here’s a link to some guy riding his Ducati 1098 with an on-board camera that I found on You-tube.
Cheap thrills for the masses…
http://www.youtube.com/watch?v=G3-_GMEtNWY
July 27th, 2008 at 11:06 am
#135 Lurtz comments on the $40K hypothetical MSRP.
For better or worse, GM will decide how many to make, and then the market will decide their selling price. The MSRP may be a starting point but will never be an ending point. Look at the present truck market for an example.
GM apparently will make only a few (10K) in the first year. Interest is high. Therefore actual prices are likely to be high, as there are enough rich CA moonbeams to buy them all at $40K or more. Sometime thereafter, if GM starts making Volts in larger numbers, the price will come down.
July 27th, 2008 at 11:10 am
#131 RB says: “That leaves the constant or variable issue still a bit diffuse. Of course, “constant” with the choice of a few different settings becomes similar to “variable”, so maybe the answer is “neither”.”
————————————————————————————–
Right. We could have option #3, which is a set of different constant RPMs (e.g. low, medium, and high). That would be OK by me. They could tune the engine and exhaust for those specific RPMs.
But a constant RPM engine with a single speed would be on high all the time. This would be louder, and would probably have to turn on and off a lot more, which would not only be more noticeable to the occupants, but also may increase engine wear.
July 27th, 2008 at 11:11 am
The advantage of the E-FLEX platform should be leveraged as much as possible. The primary load (if not the only load) of the ICE is a generator. I would think that all of the accessories will be electrically powered devices. An ICE should be designed to handle this load efficiently. Another aspect is to consider is the service factor…% of time the ICE is operating.
Several posts suggest that a “standard” engine will increase economies of scale. I agree…except GM has indicated that they are committed to the E-FLEX platform by suggesting 500K vehicles in the first 3-5 years of production. Can an engine be labeled “standard” with 500K units in the field?
July 27th, 2008 at 11:12 am
$40k is merely out of the picture for me. I cant afford $40k for a vehicle. $20k is something I can work with.
I went to my credit union homepage and used a vehicle loan calculator. At 5%, a $40k loan for 48 months is $921.17. The same loan for 60 months is $754.84. That is a house payment (60months) or more (48 months) and I along with most Americans cannot afford a second house payment per month.
There are a lot of Americans who make 6 figure salaries but most do not and dont come close to it. The price needs to come down considerably or GM can manage to expect small sales.
July 27th, 2008 at 11:15 am
The Prius with a Plug-In conversion done to it is around $30,000. What’s the bid deal about the Volt?
July 27th, 2008 at 11:31 am
DO NOT WORRY ABOUT THE DURABILITY OF THE ENGINE. For your information GM has had more than one engine on wards 10 best engines list. I for one would love to be able to tap into that 50kw generator during an extended power outage or an emergency or how about having 50 kw at the campsite, this would be another great reason to buy a Volt. Watch out Japan the sleeping giant is now awake and on the move.
July 27th, 2008 at 11:31 am
#141 Paul asks: “The Prius with a Plug-In conversion done to it is around $30,000. What’s the bid deal about the Volt?”
————————————————————————————–
The Volt has 40 miles of all electric range (AER).
The plug-in Prius has 0 (zero) miles of AER. That’s because the Prius needs the gas engine to go faster than 45 miles per hour. At highway speeds, the Prius gas engine is always on. So plugging in the Prius only helps to get better gas mileage.
By contrast, if you drive the Volt less than 40 miles per day, you never have to go to the gas station. So the Volt is about not using gas at all.
To put it another way, the Volt is an electric car with a gas engine assist. The Prius is a gas engine car with an electric motor assist. If you took the gas engine out of the Volt, it would still work fine for 40 miles per charge. If you took the gas engine out of the Prius, it wouldn’t work over 45 mph.
July 27th, 2008 at 11:40 am
#109 omegaman661.
“The oil companies have plants over seas and over here. Removing tax breaks means more of those jobs would transfer overseas. ”
As a factual matter you have it backwards. The lack of taxation on unrepatriated earnings, which is what he’s referring to, may be justified — that’s debatable — but everyone agrees that it leads to jobs being moved overseas. You are right that the rules apply to all companies, but that doesn’t mean they’re not a subsidy for the oil industry because they’re also a subsidy for other industries.
“2 thru 4. The oil companies have absolutely nothing to do with American foriegn policy. Chevron/Exxon/Texaco etc do not decide if w’e go to war or not. ”
You are absolutely right that oil companies do not decide to go to war. But to claim that they have “nothing to do with American foreign policy” is simply crazy. Of course they do. Alan Greenspan in his book made this point and, when this created a bit of a furor, he basically said that he assumed anyone who knew anything about the Iraq war undestood it was all about oil and the oil companies. The WMD stuff was just spin to sell the war. (How many people who were there have to say this?)
On this point, do you think it’s just happenstance that only US multi-nationals have gotten no bid contracts to develop the Iraq oil fields? Or that Hunt Oil — a big financial supporter of George Bush — got a no bid contract for oil in the Kurd Region in violation of the Iraqi Constitution and our stated foreign policy? (Look this one up — you’ll find that recently produced emails show that the State Department was doing everything in its power to make this deal happen while publicy decrying it). If you believe in that these contracts were won on the basis of merit then you are one of the most naive men in America.
Make no mistake: We spend tens of billions of dollars a month advancing the interests of our multi-national oil companies. Of course we do that because we’re addicted to foreign oil and they’re supplying the substance we’re addicted to. But if you think of this in drug terms, the oil companies are pushers, and pushers aren’t generally very popular folk.
July 27th, 2008 at 11:43 am
#142 chevonly says: “DO NOT WORRY ABOUT THE DURABILITY OF THE ENGINE.”
————————————————————————————–
I know that GM builds good engines.
The problem is that if you run any engine at a constantly high RPM, and turn it on and off every minute, then it will tend to wear faster. That’s why I don’t like constant RPM engines. It would be better to vary the engine’s RPMs to match the average power demands of the vehicle.
July 27th, 2008 at 11:44 am
“GM has to rely on profits and take risks.”
________________________________
- That sentence is spinning in my head and don’t make me feel good. I would be afraid to be the firt year owner of a Volt car…
-We all know the experience of the Saturn at the beginning !
(A car reinvented by GM!!!!)
- I prefer GM to import the technology and the know-how from Europe.
- Finally, I yould be very surprised that a Volt will sell for 30k in 2010 or more…
Good luck to GM anyway !
July 27th, 2008 at 11:47 am
143 >> if you drive the Volt less than 40 miles per day, you never have to go to the gas station. So the Volt is about not using gas at all.
No absolute was ever declared. Volt will consume a small amount of gas from time to time for gas & engine up keep. The goal is dramatic reduction, not elimination.
.
143 >> If you took the gas engine out of the Prius, it wouldn’t work over 45 mph.
Do a search on “running out of gas” and you’ll find plenty of reports where Prius owner kept on driving at highway speeds after the tank went dry. It’s not the most efficient choice and there isn’t much battery capacity available, but the speed certainly is possible nonetheless. After all, the PSD is designed to keep the engine motionless up to 62 MPH.
July 27th, 2008 at 12:01 pm
#140 mikel,
I agree completely. In the end, it will be about price. There will be a relativly small percentage who will be willing to pay more, but this doesn’t represent mainstream America.
GM originally said the Volt would be priced “nicely under $30,000″. Since you have your credit union page handy, what would be the monthy payments on something like that?
There are a number of possible reasons GM has raised the price from $30K to $40K:
1) They are trying to get the U.S. government to give tax credits for PHEVs.
2) They want the niche EV (wealthy) buyers to bite first.
3) GM is no longer able to lose money on each car while the volumes ramp up.
4) The batteries really are inherently expensive.
Of these, I suspect a combination of 1-3. I don’t believe batteries will be expensive once volume pricing kicks in.
July 27th, 2008 at 12:11 pm
#147 john1701a,
I Googled Prius “running out of gas” and couldn’t find anything on 62 MPH. Do you have a link?
July 27th, 2008 at 12:14 pm
With the engine issue decided, we need a new topic.
How about this….
When the production body Volt is revealed in the near future, I hope we get some details on the dashboard display information.
I see a real need to prominently display a dynamically updated “Predicted Available Range” number. This of course would be computed using the battery pack SOC and the available fuel load data. Perhaps an audible reminder would chirp / chime when the Predicted Available Range went below a value that you entered via a “Settings” menu during your “Setup” of the vehicle.
Does the Prius display this type of information ?
July 27th, 2008 at 12:15 pm
Dave G
When GM says “steady state” they mean constant RPM. “Dynamic” would mean that the engine responds to varying load. That’s not my interpretation…that’s just what it means.
Remember, the engine can still have variable power output at a fixed RPM….this occurs by simply changing throttle position. It’s analogous to cruise control. Speed is maintained, but power is increased when going up a hill, or decreased when coasting down a hill.
This is great news. Optimizing an engine to run at a fixed speed is much easier than to design one that has a large RPM range. Think of all the efficiency gains they can make by specializing head design, timing, intake runners, and exhaust tuning etc.
Additionally, the air/fuel ratio of a turbo charged engine (forced induction as opposed to normally aspirated) must be kept slightly “rich” compared to a well tuned n/a engine due to exhaust gas temperature and pre-ignition issues.
From a cost standpoint. The 1.4L is an obvious choice. This is the same engine that will be used in turbo-charged form in a variety of small cars in GM’s lineup in the coming years, though those vehicles will have more traditional drivetrains. There will be no need for forged pistons or crankshafts in the n/a version…so the noise issue that someone mentioned earlier should be a non-issue. The other benefit of the 1.4L is that it will be built in Flint, which is not far away from where final assembly is planned. I’m not sure where the 3 cyl. turbo would have been built.
July 27th, 2008 at 12:15 pm
#90 Joe
You have a good point. The problem, however, is that new cars from companies like Toyota and Honda are consistently of good quality. With GM most new cars are good but you can get a clunker. Here’s a great quote from an article that sums up the problem for GM far better than I could:
“There’s some truth to that. But the argument naively misses a huge point. While some brands like Mercedes moved way up the charts this year and others, like Chrysler, tumbled way down, hot names like Honda and Toyota are in the top 10 every year. Every year!
Consumers love and trust those brands. And those companies have been dining on Motown’s market share for decades now. Sure Detroit is close, by the numbers anyway. But consumers won’t believe that Detroit is as good as Honda and Toyota until they beat them and beat them consistently in J.D. Power surveys, Consumer Reports studies, word-of-mouth recommendations and just general buzz. I’m sorry, why should a guy who’s on his third Toyota or Honda buy a Chevy? Because the initial quality is almost as good and the disparity is statistically miniscule? There’s a great sales pitch. ”
FWIW I think GM and other US brands are enjoying something of the same advantage over German brands at the moment. I also think that GM has a chance to recapture some market share from the Japanese brands with the Volt technology — it’s one of the reasons it should be so exciting for GM. Since GM has done a very good job of rejuvinating the Cadillac brand I think Volt technology in a performance Cadillac would be a great fit (I don’t think this has been missed by Lutz).
July 27th, 2008 at 12:20 pm
I think GM is on the right track. The 4 cylinder engine uses less fuel. A turbocharged engine can produce more HP in a smaller package, but isn’t without added complications in engine control, reliability, and durability. If I recall correctly, the turbocharged 3 cylinder is a redesign of a normally aspirated engine so there’s some added risk of relatively new design. Ever see a turbo with F.O.D. or price a turbo replacement or repair? Probably little risk, but still some.
GM is instead using a larger, lighter, less highly stressed, normally aspirated engine, that costs less and is more fuel efficient? What’s there to complain about? It’s going to be lighter, cheaper and more fuel efficient. You might have to give up a little space for the larger engine (maybe just a little more crowded engine bay that the passenger won’t even notice) and the sex appeal of a turbo-charged engine. Big deal.
About new vehicles being too quite. A blind person could get hit by a bicycle which is even quieter than a car. Everyone else needs to LOOK a pay closer attention to their surroundings.
July 27th, 2008 at 12:29 pm
One poster writes: “The Prius with a Plug-In conversion done to it is around $30,000. What’s the bid deal about the Volt?” The old saying you get what you pay for applies here. Read the stories at these links:
(Plugin Prius catching on fire)
http://www.autobloggreen.com/2008/06/18/converted-plug-in-prius-destroyed-by-fire/
http://gizmodo.com/5018111/aftermarket-plug+in-prius-battery-causes-balls-of-fire-explosion
July 27th, 2008 at 12:30 pm
#146 Robert V. (Canada) says :”- I prefer GM to import the technology and the know-how from Europe.”
————————————————————————————–
I have nothing against European or Japanese technology, but in this case I think North America has more experience. For example, how many companies have put an Induction motor in a car?
- GM (EV-1)
- Tesla (Roadster)
- AC Propulsion (tzero)
So I don’t think Europe has a lot of EV specific know-how to offer GM.
Having said that, many aspects of the Volt are multi-national. For example, the battery cells are manufactured in Asia. Some battery packs are assembled in Germany. Some of the engineers are from Europe. So I don’t see a lot of NIH engineering attitude with the Volt.
July 27th, 2008 at 12:30 pm
#82 Proud Americn
“you can stick it to the oil companies AND the Prius people”
“Toyota Prius drivers are just greenie snobs.”
“good ole U S of A car not some tin can Prius.”
Have you ever heard of the saying…”If you have nothing good to say, don’t say anything at all.” I’m sure GM likes folks promoting their products, but negative comments like these only helps your perceived adversaries. If I use your descriptive phrase, it seems that several car buyers are proud owners of a “tin can” (1 million plus).
<<<>>>
http://www.greenbang.com/3149/guess-how-many-people-drive-a-prius/
So maybe GM needs to start selling a vehicle that could be considered a “tin can” by some people. I’m sure a few so called “greenie snobs” own a Prius…but I’ve never understood the distaste that some folks have for individuals or groups wishing to make the world a cleaner place. Some of these groups ask people to recycle and/or minimize the amount toxins that they emit into the air from their vehicle. Maybe it reminds the naysayers of the dreaded request during their childhood to pick up their toys and clean their room.
However like all groups, some bad apples are in the barrel…hence some “bad” owners of the Prius exists.
“They act like repairing a car is too good for them.”
I’m sure that has some truth (see snobs above). I know that some folks enjoy servicing cars so much that they will purchase an unreliable vehicle. However, most people just have different hobbies and abilities. Me…I do not like getting stranded on the highway or dealing with an undependable vehicle.
Mostly, it seems that you are upset with the success of a foreign company’s product(s) and the effect on GM’s domestic labor force. Also, foreign oil dependence appears to be a point of contention. A difficult question that you should ask yourself…”Would GM be designing the Volt if the Prius was not a success?”
July 27th, 2008 at 12:32 pm
No possible way GM,…and I mean NO POSSIBLE WAY that GM will have a car ready for anything near 30K.
Their CEO and “trickly down” management need to make millions of dollars for having a Master Degree in Business, etc. How many Americans have Masters Degrees in Business? Can you say,…” more than 200,000. We don’t need our CEO’s making 20 million plus – ludicrous. They have nothing to do with product developement, just listen to what the people want and cut out 100-200 million dollars from people who really become redundant and money that can be used for further R&D.
All the Best
July 27th, 2008 at 12:34 pm
I’m one of those (I’m sure, many) who don’t drive more than 40 miles daily, barring the annual trip to Nevada. (Vancouver B.C./Nevada)
I’d purchase my Volt minus the ICE, if possible. On that rare longer trip I’d carry a small Honda generator (or similar) and extend my coffee stops, as necessary.
Perhaps, as EV use grows, we will see metered charging facilities at rest stops and restaurants. Now THERE’S an idea for MacDonald’s that’s always looking to green up its image.
Happy to see that things are moving along.
July 27th, 2008 at 12:44 pm
I own a prius, can’t wait til the Volt gets going! As far as Air Condtioning, I can see a difference of about three miles per gallon,the new Prius is going to have solar cells for the Air, what about the Volt too!
July 27th, 2008 at 12:48 pm
#151 JeremyK says: “When GM says “steady state” they mean constant RPM. “Dynamic” would mean that the engine responds to varying load. That’s not my interpretation…that’s just what it means.”
————————————————————————————–
Then explain this statement from Larry Nitz in the article:
“He does say though that the battery could be discharged below 35% if it has to on rare occasions, but that when steady state resumes, the battery will recharge as the engine then produces more output than the car requires at that time.”
From this statement, I interpret “steady state” as the engine supplying just enough power to meet vehicle demands, and “dynamic” as peak power demands that drain the battery.
In any case, I think constant RPM is a bad choice, because that RPM would have to be capable of max power, so it would be a fairly high RPM. This means the engine would be fairly loud at lower driving speeds.
In addition, at lower driving speeds, a constant RPM engine would produce too much power even at minimum throttle, so it would have to be turned off and on a lot more frequently. Both the noise and increased cycling would be distractive to the driver and passengers. The increased cycling would also increase engine wear.
Last summer, Rob Peterson, GM spokesman, stated that the engine will be variable RPM:
http://gm-volt.com/2007/08/29/latest-chevy-volt-battery-pack-and-generator-details-and-clarifications/
Here’s the quote:
“Interestingly, the motor will likely be programmed to increase rpm when you step on the gas and quiet down when you stop to “simulate” the driving effect people are already used to. This will avoid the sudden unexpected ons and offs.”
So far as I know, GM has not said anything since to contradict this.
Lyle,
Could you ask GM if the gas engine is Constant or Variable RPM?
July 27th, 2008 at 12:50 pm
#105 Tagamet
If you go back and re-read comments #27 and #28, can you see how they might sound a little high and mighty?
“Seems a BUNCH of people in the previous thread didn’t know squat about what they were talking about. Thanks for the quick follow up to put on the “I know better than GM” speculation to bed.
And now this thread is again filled with a bunch of uninformaed posters as well. *sigh*”
They don’t provide any context or get very specific. I will give omegaman66 and Grizzly the benefit of the doubt because I know them. but comments #27 and #28 leave room for misinterpretation.
July 27th, 2008 at 12:58 pm
#158 skeptikool says: “I’d purchase my Volt minus the ICE, if possible. On that rare longer trip I’d carry a small Honda generator (or similar) and extend my coffee stops, as necessary. ”
————————————————————————————-
When you say “small Honda generator”, what do you have in mind?
The Volt uses around 25kW (25,000 watts) at highway speeds.
Are you talking about towing a generator?
July 27th, 2008 at 12:59 pm
How about a compressed natural gas version of that 1.4L. You’d get a bit less power out, but the Volt should only need about 25kW at highway speeds so it’s a good match. This has some great Green Appeal and T. Boone Pickens would probably help fund the conversion.
July 27th, 2008 at 12:59 pm
I wrote “The ICE will either run at a steady state or at a small rpm range. It will not run in a range from 500rpm to 6000rpm.”
————————————————————————————–
Dave G ask “What is your source of information for this?”
My sourse is gm-volt.com. Previous post by Lyle concerning this issue and the recent post (graph-http://www.gm-volt.com/i/voltchart.jpg) that shows that the SOC during extended driving will have the battery not holding a steady 35% SOC!
July 27th, 2008 at 1:03 pm
One important factor regarding the engine and efficiency is how much it will cost to drive the car every year. Under a few reasonable assumptions, the total cost to drive 15K miles for the Volt would be $480/year (80% electric, 20% gas @ 50MPG), but at additional weight and reduced engine efficiency, the electric range could suffer along with the fuel efficiency. I estimate maybe $580/year (see calculations below). So, for a 10% degradation in performance, you could see a 20% increase in fuel costs. (This of course is just back on the envelope calc, so please don’t take me to task on this.)
Since the engine is known now, along with the target weight (3,140 lbs?) and drag coefficient (0.26 to 0.29?), is it possible to come up with a pretty accurate estimate of the MPG. In most cases, the engine would kick in on the highway, so only the highway MPG could be considered.
—————————————–
15K Miles/year
80% from all electric drive
20% from gas
cost:
Electric:
12K miles at $0.02/mile ($0.10/kilowatt-hour @ 5 mi/kilowatt-hour)
= $240
Gasoline:
3K miles at 50MPG ($4/gallon)
= $240
total = $480
—————————————–
If the car had more weight, then maybe it would have a 10% reduced range and a 10% reduction in MPG. That in turn would change the gas to electric driving ratio (for example, from 80-20 to 75-25). Furthermore, the miles/kilowatt-hour might also change (from 5mi/kw-hr to 4.5mi/kw-hr).
Thus the total cost is:
Electric:
11,250miles at $0.0222/mile ($0.10/kilowatt-hour @ 4.5 mi/kilowatt-hour)
= $250
Gasoline:
3,750 miles at 45 MPG ($4/gallon)
= $333
total = $583 or a 21% increase in fuel costs
July 27th, 2008 at 1:07 pm
Isn’t this too big of an engine?
July 27th, 2008 at 1:09 pm
#157 FBerry says: “No possible way GM,…and I mean NO POSSIBLE WAY that GM will have a car ready for anything near 30K.”
————————————————————————————–
Actually, I think $30K is a little high.
The Volt is based on the Chevy Cobalt platform, which has a sticker price of $15,070:
http://www.chevrolet.com/cobalt/
Last year, Tesla leaked the price they pay for their battery pack at $22K. They use a 53kWh pack to get their 220 mile range. The Volt’s battery pack is much smaller (16kWh). At Tesla’s pricing, the Volt’s battery pack should cost about $6600 (16/53 * $22K).
Now let’s say the rest of the Volt stuff costs $5000 more than the Cobalt. At that price, the Volt should have a sticker price of under $27K.
July 27th, 2008 at 1:11 pm
Volt would be a good commuter car BUT CAN I TAKE IT ON A LONG CROSS COUNTRY TRIP WITHOUT PROBLEMS? Say 2 week vacation or would I be overtaxing something???
July 27th, 2008 at 1:24 pm
#164 omegaman66 says (regarding constant or variable RPM engine): “My sourse is gm-volt.com. Previous post by Lyle concerning this issue and the recent post (graph-http://www.gm-volt.com/i/voltchart.jpg) that shows that the SOC during extended driving will have the battery not holding a steady 35% SOC!”
————————————————————————————–
Do you have a link to the previous post by Lyle concerning this issue?
Last I heard, GM said it would be a variable RPM engine, but that was last summer:
http://gm-volt.com/2007/08/29/latest-chevy-volt-battery-pack-and-generator-details-and-clarifications/
Also, the graph from last summer had lots of humps and dips. So I wouldn’t infer a lot from that, since this is where they said it was variable RPMs.
The humps and dips could have a lot more to do with acceleration and uphill driving, where the peak horsepower of the electric motor exceeds the average power that the gas engine can supply. Larry Nitz did mention that subject specifically.
Lyle,
Could you ask GM if the gas engine is Constant or Variable RPM?
July 27th, 2008 at 1:24 pm
Dave G.
“but that when steady state resumes, the battery will recharge as the engine then produces more output than the car requires at that time.”
He is specifically saying that the engine is producing more power than the vehicle demands. It is charging the battery.
It makes sense that the engine will be set up for maximum efficiency. If it is producing more power than the vehicle demands it will charge the battery until it hits an upper set point at which time the ICE will shut down and battery operation will continue until the lower set point is hit and the ICE starts up again.
If the vehicle is traveling at high speed or up a mountain and the ICE cannot supply the power needed while operating at maximum efficiency, then it will increase to a speed that will supply the power if it can.
This is conjecture, but the engine could be tuned for several efficient setups, but I believe the most efficient will be producing the least power.
Len
July 27th, 2008 at 1:27 pm
#168 wwskinn3 asks: “Volt would be a good commuter car BUT CAN I TAKE IT ON A LONG CROSS COUNTRY TRIP WITHOUT PROBLEMS? Say 2 week vacation or would I be overtaxing something???”
————————————————————————————–
No problem. That’s exactly why they have a gas engine range extender. And by the way, 50 miles per gallon is not too shabby!
July 27th, 2008 at 1:31 pm
#6 4banger
Is that an inline-4 or a V-4 ? I4
Is than OHV or SOHC or DOHC ? don’t know
Are those cast pistons or forged ? don’t know
Is that cast iron block or aluminum or ceramic ? Iron
Just how good is that motor anyway ?? (i hope GM knows what it is doing) They use the motor in europe now.
General comment
I like hoow it was said that the I4 is a lighter motor than the I3 with turbo. I have said that a couple times here. Also I have seen the block for it, it is really small. compare it to a loaf of wonder bread in length.
July 27th, 2008 at 1:44 pm
#170 Len,
Thanks for the explanation, but I’m still trying to figure out what exactly Larry Nitz means by his term “steady state”.
If, as other people posting here suggest, the term “steady state” is synonymous with Constant RPM, then how can “steady state” resume? If “steady state” resumes, then it is not constant, so I wouldn’t interpret “steady state” as Constant RPM.
I’m interpreting “steady state” as the time when the engine is perfectly matching the power demands of the car. When you hit the accelerator hard or go up a steep hill, the engine is no longer in steady state because it is not keeping up with the dynamic power requirements of the vehicle.
Obviously, when you let up on the accelerator or go down hill, the engine can now supply enough power for the electric motor as well as recharging the battery back up to around 35%.
July 27th, 2008 at 1:52 pm
…told you so…
July 27th, 2008 at 2:07 pm
Iron block? How long has it been since a small 4 cyl had an iron block? It’s been a while, it will be aluminum.
July 27th, 2008 at 2:15 pm
#163 Dr Mark says: “How about a compressed natural gas version of that 1.4L. You’d get a bit less power out, but the Volt should only need about 25kW at highway speeds so it’s a good match. This has some great Green Appeal and T. Boone Pickens would probably help fund the conversion.”
————————————————————————————–
I like what T. Boone Pickens is doing with wind, and his point that America can’t afford to pay $700 Billion a year for oil. We’ll go broke if we keep this up.
But I think T. Boone Pickens plan for compressed natural gas (CNG) engines is a bit off. These engines are extremely inefficient, worse than fuel cells! See here (pages 3 & 4) for details:
http://www.stanford.edu/group/greendorm/participate/cee124/TeslaReading.pdf
It turns out that if you use natural gas to make electricity that powers an EV or EREV, you are 3-4 times more efficient. We can’t afford to rebuild our transportation sector on horribly inefficient technology, however appealing T. Boone Pickens makes it sound.
I would like to hear more about bio-diesel from algae. After all, algae is what made oil to begin with. They can make 20,000 gallons of vegetable oil per acre per year using algae. That would power a lot of diesel engines. If I were a truck driver, I would be screaming about algae…
July 27th, 2008 at 2:55 pm
#171 Dave G – thanks for the info. I have several friends who are concerned about the same thing – taking long trips. They felt that you would wear out the charging system, battery or engine running at only one speed by driving – say 65 mph for hours on end all day. The issue was weather this could be your only “all around” car or a 2nd car for commuting. I appreciate your clarifying it.
July 27th, 2008 at 2:57 pm
Great post! Of course us techie leaning folks would think this.
I was very happy to see the SOC graph reappear on the last post. This, or a least a version similar, was included in an article written just after the press junket through GM’s facility a few months ago. This showed a departure in GM’s strategy for charge sustaining mode. Before that point, GM had mentioned battery only operation until a set SOC point to initiate charge sustaining mode. GM gave 30% SOC as the initiation point. Once reached, GM’s philosophy had been that the ICE would run continuosly and would vary output to keep the battery as close as possible to 30% SOC for the return home. This graph indicated they had changed their strategy and determined that the ICE would be used to to power the vehicle as well as charge the battery for small cylces when there was surplus power available. These “small cycles” are represented on the graph around the Extended Range Mode inition point. The discussion in the forum about this graph surmised what GM’s engineer confirms here:
“He notes that the engine never has to perform dynamic response, that only comes from the battery and electric motor side.”
This is very, very good IMHO. They will optimize around a specific output. Perhaps as some have surmise, the generator will still have a multiple ouput points (@10KW, @25KW, 50KW) as GM described in the past but the GM engineer’s comments here indicate that it will be setup to deliver constant 50KW. If accurate, this does seem a bit high since it will result in short cycles for many driving conditions. My guess is that the reality is there will be at least 2 steady-state modes on operation (25KW & 50KW). I’m sure GM engineers will sort this out for the best. There will undoubtably be lots fine tuning done from here to production. An interesting feature will be that the Volt will have a peak efficiency point where the vehicle load matches the stead-state output of the generator. It would be nice if the display could indicate this point and if you could set the cruise control for it. Note, this will NOT be a constant velocity point like cruise control typically operate around. Auxiliary loads and outside conditions will dictate the velocity.
Best of all, this shows GM has focused in on a fundamental advantage of their EREV concept. This bodes very well for future generations of EREV’s. They can use this newly dedicated advanced powertrain engineering center to develop a purpose designed and purpose built ICE (or other power sources) for future EREV generators. While the I4 choice for the Volt is absolutely the right way to go for now, future generations should take more advantage of the drastically different application from traditional ICEs that EREVs present. This constant moderate load application will most likely be the dawn of widespread acceptance for rotating engines of some manner. Rotating engines are much more adept for supplying constant power than reciprocating engines. Hopefully GM is fast at work on their first purpose built engine for future generations of EREVs.
To some up this announcement for the 1.4L N/A ICE vs 1.0L Turbo:
-Less expensive (WIN)
-Less weight (WIN)
-Less complexity, more reliability (WIN)
-Less noise, less vibration (WIN)
Seems pretty dang good all around.
July 27th, 2008 at 3:10 pm
The critical thing is that the motor should never charge the batteries fully. When you stop, you want to be able to top up the batteries with the electrical sources available to you. Even at the full day time electical rate, driving is far less expensive on electricity than on petrol. By the way, what will the range of the Volta be on purely electrical power.
July 27th, 2008 at 3:15 pm
#178 Koz
“To some up this announcement for the 1.4L N/A ICE vs 1.0L Turbo:
-Less expensive (WIN)
-Less weight (WIN)
-Less complexity, more reliability (WIN)
-Less noise, less vibration (WIN)
Seems pretty dang good all around.”
That does indeed sum it up! I can’t wait to put theory into action.
July 27th, 2008 at 3:21 pm
#179 William Hughes-Games asks: “By the way, what will the range of the Volt be on purely electrical power.”
————————————————————————————–
40 miles all electric range.
50 miles per gallon thereafter (assuming the 1.4L engine hasn’t changed that).
July 27th, 2008 at 3:22 pm
Voltik #92
“This makes Voltik smile, looks like my research and dyno runs on the 1L turbo and 1.4L na were right on. 1.4L pulled the load better and took less fuel per hour doing it.”
*** *** ***
Good work, and just as we discussed on a previous thread. Really it’s not that surprising that the smallest power plant isn’t the lightest, simplest, or the most efficient for a particular application. I remember just how many people wrote off the 50mpg when the 1.4 was a tentative announcement in a previous thread. I liken this to many 4 cylinder cars that don’t get the hwy mileage of my 6. In a strange way the reason is similar in that they must work harder to maintain that speed and in so doing lose efficiency.
July 27th, 2008 at 3:23 pm
#179 William Hughes-Games
“By the way, what will the range of the Volta be on purely electrical power.”
GM is targeting 40 miles all electric-only range (AER) for end of useful battery life. This is said to be for city range. Bob Lutz has hinted that they may program it for more when new. Personally, I’m hoping they let the user decide, to some degree, on how large the battery cycle can be for exceptions to allow for more range if needed occasionally.
July 27th, 2008 at 3:28 pm
@ 111 – Tagamet:
“If you use a real computer (not a Mac) you can right-click and save that chart to your computer.”
Come on….this an unfair, ignorant comment. Apple computers let you do this with a right click or with a regular click+control button.
In addition, Apple computers offer you far more options for capturing this picture, you can click and drag, right click, control click or use Ctrl+Shift+4 to capture a snapshot of only the chart…unlike with windows where you can only take a picture of your entire screen.
July 27th, 2008 at 3:34 pm
OK, it’s obvious that the ICE could be controlled in multiple ways, and nobody knows exactly how it will be done yet. I’ll bet GM is still figuring it out.
So, we all know what Lyle has to do to satisfy his rabid followers … who will no doubt continue to offer a variety of opinions and interpretations throughout the night! And some will even turn out to be right!
July 27th, 2008 at 3:40 pm
#183 Koz,
As I understand it, the battery pack always cycles between 35% and 85%. The battery pack is designed to provide 40 miles of all electric range at end of life (10 years or 100,000 miles). So when the battery is new, it will naturally have more storage capacity, perhaps 45 miles or more.
This is not due to any specific programming, but rather just because the battery will age, and GM still wants to have 40 miles of range after the battery ages, so they have designed the battery to have a little extra storage to compensate for aging.
July 27th, 2008 at 3:41 pm
#184 Dan
Not for nothin but Alt+Print Screen copy only the active window in Windows. Keep pushing Apple though, I kept there stock when dumping the rest (including Microsoft) last year.
July 27th, 2008 at 3:42 pm
#185 Steve,
Yes. Well said!
July 27th, 2008 at 3:45 pm
#186 Dave G
That has been said but is far from decided. People have also talked about extending the discharge window as the battery ages to keep the range consistant and lengthen battery life. Personally, I’m hoping they allow me to use what I want (within reason) out of the box, otherwise it’s aftermarket we go. I’ll doubt we’ll know many of these details until production and certainly not until they confirm a battery supplier choice.
July 27th, 2008 at 3:50 pm
Regarding the photo, most of what you see is the dynomometer. The actual ICE is just the thing in the middle. To the left in the photo is an aluminum housing with ribbing that is actually a transmission and differential from some other car. It’s used to couple the engine to the dyno. You can see shafts going left and right from it that would normally go to the front wheels. The electric motor thing on the right is probably the brake for the dynomometer – essentially a generator that absorbs the power being generated by the ICE so they can measure torque and horsepower. In essence, the only part of the ICE is right in the middle of the photo – all the rest is ancilliary test equipment. This is a good choice from GM. I met Larry Nitz last week in San Jose and was very impressed with his knowledge of powertrains, hybrids, and transmissions. I think GM is doing the right things and has the right people on this project.
July 27th, 2008 at 4:00 pm
Paul (#60)
Chevron’s battery patent will expire in 2014. Just think where current battery development would be if GM would not have sold this patent right to Texaco (taken over by Chevron).
He is the batteries: http://www.evnut.com/rav_battery_data_sheet.html
Chevron sued Panasonic and Toyota (they won) to stop them from using these batteries.
July 27th, 2008 at 4:17 pm
Very excited to hear about these details. Keep the info flowing.
July 27th, 2008 at 4:18 pm
This is all looking a lot like the configuration like the Ford Escape / Mercury Mariner configuration. We own one ourselves, and love it. Wish the battery was Li-ion though; it’s a NiMH so it doesn’t quite have the power duration. We’ve been getting at least 32 at worst (sloppy driving), but can get as good as 39 mpg (smart hiper driving). It has a similar configuration (1.4L 4/cyl with electric drive.) Not bad for an small SUV that will comfortably carry 5.
If the Volt is more aerodynamic and less weight, the it should do very well. I’m very excited! Bring it on GM!
July 27th, 2008 at 4:24 pm
#186,
I’m hoping the 100,000 mile life is the life of the battery if the car runs the entire 100,000 on electric drive and no gas or the life of the battery if the car runs on gasoline the whole time without ever plugging in and any mix inbetween.
July 27th, 2008 at 4:44 pm
#194 law,
Actually I’m not sure if GM is calling 100K or 150K miles end of life, but note that driving on gas also stresses the battery. Every time you accelerate hard or go up a steep hill, the battery discharges to provide the electric motor with power. When you let up on the accelerator or go down hill, then the gas engine recharges the battery back up to around 35%. So when the gas engine is on, the battery is frequently charging/discharging, usually by small amounts.
July 27th, 2008 at 4:50 pm
#191 BillInInd
#60 Paul
From everything I’ve heard, a 16kWh NiMH battery pack would be twice as large and twice as heavy compared to Li/Ion.
Also, I believe NiMH has more issues with self drain. In other words, if you left a NiMH based EV parked for a month or two, it will have lost a lot of it’s charge just due to the self drain of the chemistry.
Bottom line: let’s hope no oil companies get their hands on Li/Ion patents.
July 27th, 2008 at 4:55 pm
#168 wwskinn3 asks “Volt would be a good commuter car BUT CAN I TAKE IT ON A LONG CROSS COUNTRY TRIP WITHOUT PROBLEMS? Say 2 week vacation or would I be overtaxing something???”
You can do it with no problems as related to the car itself. The question is whether you will have the trunk space you need to take along your stuff. The Volt is after all a small car. Maybe you travel light. If so, great.
July 27th, 2008 at 5:09 pm
#178 Koz says
“To some up this announcement for the 1.4L N/A ICE vs 1.0L Turbo:
-Less expensive (WIN)
-Less weight (WIN)
-Less complexity, more reliability (WIN)
-Less noise, less vibration (WIN)
Seems pretty dang good all around. ”
I agree. The one downside is that it is too big for the space available, requiring GM to “reconfigure the packaging”. Between the lines, one knows that something did not work out as expected.
July 27th, 2008 at 5:25 pm
#132 mikel discusses the impact of higher cost for the Volt.
No doubt everyone at GM marketing is well aware that there is a very limited market for cars at $40K as compared to well under $30K, and no doubt GM wants to have a product for the much larger number of people who can be sold at a lower price.
In this regard, keep in mind that we have had hints that the Volt, if and when successfully introduced, would be followed by “Volt2″, a car that might take advantage of Volt development and be much less expensive. But nothing definite.
July 27th, 2008 at 5:32 pm
Thomb,
Maybe it’s just *me*, but the thread seemed to be both rambling and flat. There certainly seemed to be a wider than average “range” of comments. (shrug).
My post about the different computer platforms was clearly just an attempt to add some pepper to the discussion, which in hindsight was definitely er, ill-conceived. (g).
Not being a gearhead nor an engineer, I’m really out of my element (except for the peppering part).
Lyle, any chance of seeing the *interior* soon????
Be well,
Tag
July 27th, 2008 at 5:44 pm
#197 RB – You can do it with no problems as related to the car itself. The question is whether you will have the trunk space you need to take along your stuff. The Volt is after all a small car. Maybe you travel light. If so, great.
1 wife – no kids or animals – 1 small bag each – no problem. Try not to take much stuff. Want to travel Route 66 again – this time in a Volt.
July 27th, 2008 at 5:50 pm
My goodness. I go away for a day and look how many comments we have.
I remember the days when it was easy to read all the comments in a thread.
It is very time consuming now. At the same time, it is great that the popularity of this site and Volt are taking off.
July 27th, 2008 at 5:58 pm
#201 wwskinn3
You’ve got it made!
Have a great trip.
(Now all you need is the Volt.)
July 27th, 2008 at 6:07 pm
#DA @39 — Thank you for the substantial and interesting analysis of the consequences of the engine choice. The other side of the argument, I guess, is the “going up the mountain” requirements. Also, I’m not sure that fractional charges accumulate into equivalent full charges in the way you did it. But overall you make a strong case that the engine is just too big.
July 27th, 2008 at 6:12 pm
190 MH & 201Tag……..
Hey Tag, I’ll try my hand at “peppering things up” a little here. The photo at the top has always bothered me. It shows only the Volt’s ICE, not its generator —thus it is NOT a picture of the Volt’s complete range extender!
I believe the engine’s black valve cover & block are at the photo’s upper-center and the aluminum housing at the left-center is a transaxle. The yellow jig-mounted devices on both sides couple the transaxle output shafts to sensors, and I’m not sure anything we see in the photo could be called a dynamometer. I’d guess this setup is primarily to evaluate the 1.4L engine/transaxle combination (perhaps for the Cruze?) The only thing that seems certain to me is that it DOESN’T include the Volt’s generator. OK, guys, light your flame throwers (or grab your pepper sprays)!
July 27th, 2008 at 6:26 pm
nasaman,
That’s not good news. The bugger looks too complex already (kinda like something out of Nasa). Maybe they are taking your system redundency suggestions seriously. Isn’t there a stronger case to be made for “simple = bulletproof”?
Be well,
Tag
July 27th, 2008 at 6:38 pm
If you’re wondering where Carlos (“I’ll never build an electric car”) Ghosn’s range extender engine is located, just look to the parking space on one of his electric cars and then look under the hood of that second (gas powered) car. So THAT’S where he’s putting his EV’s range extender. Seems sort of an expensive way to mount it, inside that $30,000 gas powered car.
July 27th, 2008 at 6:57 pm
While I’m logged on here, after reading thru the many posts about the ICE rpm range, it seems there’s little if any consensus that it should operate over a very narrow (but not constant) rpm range.
Since I’m not an ICE expert or an automotive engr, I’ll just try to explain what seems to me may be a reasonably accurate intuitive explanation….
Most people have gone camping and seen or used a portable generator like Honda makes. These generators are designed to operate at a nearly-constant rpm for two reasons:
1) Engine efficiency can be optimized by limiting its output to a narrow range of rpms
2) AC tools, appliances, etc are designed for 60Hz, 115V power, so generators typically operate at 3,600 rpm (60 Hz X 60sec/min = 3,600)
But what I want everyone to recall is what you HEAR when heavy loads powered by a generator are turned ON or OFF…..
From a light load to a heavy load, the generator’s regulator keeps it at very close to 3,600 rpm. It meets the huge increase in load by increasing the gasoline consumed, NOT by changing the rpm. And what do you hear? The engine noise under light loads, a quiet humming sound, increases to a deep, THROATY “drone” under heavy loads —because each combustion chamber explosion is much larger & consumes much more gas than under no load or light loads. So although the power output increased dramatically under heavy load, the rpm remained essentially unchanged.
I believe the Volt’s ICE/generator will also be essentially a constant rpm although its load (and fuel consumption) during charge cycling in the 30%-40% SOC range will be changing dramatically.
July 27th, 2008 at 7:28 pm
What causes the load in the generator? A magnetic field that grows stronger with draw/demand?
Electricity is amazing, maybe man’s greatest discovery. Far more important than ICE. Makes one wonder why are National Electric Grid is under developed. (politics)
July 27th, 2008 at 7:33 pm
Everyone is talking about lithium Ion and nickle cadmium batteries. Did I just dream this or have the new Lithium titanate batteries not proven to be superior to either of these. As I understand the situation we can expect to move the range of a car such as the Chevy Volta up to 100km with 200km achievable soon instead of the present 40 or so. At one full charge and discharge per day, these batteries should last upward of 40 years. What range would we get if we scrapped the engine and put in an equivalent weight of batteries. We are like the people who drove horse carriages before the automobile. “It will never catch on. Where will we refuel. Who is going to build the roads for these new contraptions”. Look how fast the situation changed. Once we have electric cars, charging points where you swipe your credit card will spring up everywhere, battery exchange stations will be built and so forth and smart metering will allow you to get preferential rates when there is excess power available.
July 27th, 2008 at 7:35 pm
Lyle’s post cites Green Fuels Forecast. The GFF web page gives the source information cited by Lyle and also some pictures. One of the most interesting is the picture of a car “frame” at the top, perhaps of the Volt to be, with a battery extending along the centerline.
July 27th, 2008 at 7:50 pm
#209 jan asks “What causes the load in the generator? A magnetic field that grows stronger with draw/demand?”
Yes. A coil of wire spun around in a magnetic field creates the desired current. The current in the coil also creates a second magnetic field. The original and secondary magnetic fields act one on the other. The forces are something like spinning one magnet around while holding another beside it.
The idea of things exerting forces on other things while never touching them scrambles up one’s mind. Common sense says you can’t push something without touching it.. So how do two magnetic forces cross “empty space” and push, perhaps with great force? Yet they do.
July 27th, 2008 at 7:53 pm
RB@211
Thanks for the Green Fuels Forecast site info. Interesting place, but they give an awful lot of ink to Hydrogen. (shrug).
Be well,
Tag
July 27th, 2008 at 8:07 pm
Hi Guys,
Great update on the Volt. If anyone from GM reads this stuff here’s my opinion on the price. I’d buy one at 20 to 25 K. Anymore and it is the equivalent of a house payment and no car is worth that to me.
If it is a choice between a $40,000 Volt or Honda’s new global compact hybrid at half the cost I will gladly buy the Honda.
July 27th, 2008 at 8:50 pm
Oh, Bert…you are going to regret saying that on this site
Be nice to Bert. I think he is new on the post.
As someone said in a previous post “If you can’t say something nice about someone, don’t say nothing at all” I think that line is original quote from Thumper in the Disney Bambi movie. Amazing how much you can learn from a old children movie.
July 27th, 2008 at 8:52 pm
2010 Chevy Volt, meet 14 year old engine. 14 year old engine, meet 2010 Chevy Volt.
I’m confused. First GM says the ICE will be variable RPM, now they say it will be constant RPM. Which is it? If it’s constant RPM, at what RPM will the 1.4L be running at?
July 27th, 2008 at 8:53 pm
JEC
Bert didn’t say anything that hasn’t been said dozens of times here.
Tag
July 27th, 2008 at 8:58 pm
follow up to #13 – “Nitz also states that GM has refined the charging window of the pack as 35% to 85%, whereas previously GM had said it would be 30% to 80%. He does say though that the battery could be discharged below 35% if it has to on rare occasions, but that when steady state resumes, the battery WILL RECHARGE as the engine then produces more output than the car requires at that time”.
—————————————————————-
follow up to #97 – “Lyle, no one has yet confirmed or denied whether GM has changed it’s mind about using the ICE generated power to recharge the Volt battery at a safe rate. Perhaps you could ask the GM engineers whether the above comment from the acticle is true or not. This is a huge issue to me…Thanks.”
==================================================
To all who expressed an opinion – Thanks, but I was asking Lyle (you know, the person who runs GM-Volt.com) to have GM clarify the issue. Lyle can ask Mr Nitz what he meant, I can’t. GM’s executive director of hybrid powertrain engineering, Larry Nitz, said in the acticle “when steady state resumes, the battery WILL RECHARGE as the engine then produces more output than the car requires at that time”
This quote seems to indicate that when driving on level ground (steady state), the engine will produce more power than needed to drive the car.
Please, no more replies, no more guesses, educated or uneducated. I don’t want anyone to reply except Lyle. Lyle, could you please get a clarification from Mr Nitz at GM. If the Volt simply wastes excess generated power instead of reclaiming it, I would have to reevaluate my decision buy a Volt. Any excess power reclaimed would save me money by extending my battery range. Imagine, getting to your hotel after running on the ICE, then waking to find you have enough power in your battery for another 10 gas free miles without pluging in. Priceless !
July 27th, 2008 at 8:59 pm
This is a question I am sure has been answered previously, and maybe I could research and find the answer (its late, and I am layz), but are the motors used ac induction motors, or are the dc?
I have further questions but this one needs an answer first.
Thanks for anyone’s help
July 27th, 2008 at 9:01 pm
217 Tag
True. But we all know how this subject tends to bring out a lot of emotions. Just wanted to try to quell another onslaught.
July 27th, 2008 at 9:07 pm
The Grump said:
“…If the Volt simply wastes excess generated power instead of reclaiming it, I would have to reevaluate my decision buy a Volt. Any excess power reclaimed would save me money by extending my battery range.”
SERIOUSLY?????
Tag
July 27th, 2008 at 9:30 pm
#208 nasaman,
Your intuition about a constant RPM engine has been shared by many others posting on this site.
But last summer, GM said the Volt’s gas engine would be variable RPM, and to my knowledge, they haven’t said anything to contradict that.
Also, with regard to generators that produce 110VAC at 60Hz, note that some of the newer models use variable RPM engines. Here’s an example:
http://www.hondapowerequipment.com/products/modeldetail.aspx?page=modeldetail§ion=P2GG&modelname=EU2000i&modelid=EU2000IAN
Yamaha also makes a similar design. The variable RPM gas engine power output is converted to DC, which is then inverted back to 110V AC at 60 Hz. They do this for 2 reasons:
1) to cut down on noise at low power output (advertised as “Super Quiet”).
2) to increase efficiency at low power output (advertised as “Eco-Throttle”).
My problems with a constant RPM for the Volt relate to these same 2 issues.
Yes, you can throttle back a constant RPM engine to a point, but you still need some gas to keep the engine going around, so at lower driving speeds a constant RPM engine would produce too much power. This would cause it to cycle on and off frequently, which would decrease efficiency. It would also be noticeable to the driver and passengers, and would increase engine wear.
Of course, you could increase the battery trip points around 35% to make the engine cycle less often, but this would lead to more charging and discharging of the battery, which would increase battery wear.
If a variable RPM engine doesn’t have to supply a lot of torque at low RPMs, it can be optimized to be very efficient. The Atkinson cycle is one such optimization. There are probably others.
July 27th, 2008 at 10:18 pm
hey guys I have a question….
Isn’t that range extender a little large?
Couldn’t a motorcycle engine, with an alternator, do the job?
Or, to illustrate my point (and possibly make myself look stupid…I’m a computer nerd, don’t know much about engines, though I am Qualified in Submarines (served on USS Florida ssbn-728 and uss asheville ssn-758)), could you do it with a leaf blower engine? if not, why not?
With a generator, the main thing is to for the shaft to rotate quickly right? So why would you need a huge engine? I’m sure there’s a good reason and I will look stupid for asking but somebody get back to me please
July 27th, 2008 at 10:26 pm
Brian@223
A) THANKS for your service!
B) the engine pictured LOOKS large, but it’s “smaller” than some motorcycle engines. At least that’s what someone else posted here.
Hope this helps,
Tag
July 27th, 2008 at 10:55 pm
#200 Tagamet
We’re all hanging out, talking Volt. The gearheads got lively. The Mac/PC rivalry is usually good natured ribbing. Nobody got mean. It’s all good. See you next post.
July 27th, 2008 at 11:01 pm
Thomb@225
That’s my take as well. As some have already mentioned, this particular board is – on the whole- far more civil than most.
Be well,
Tag
July 27th, 2008 at 11:10 pm
222 Dave G…..
You’re right —the Honda generator model you mention, their EU2000i (and comparable designs from other manufacturers) are more recent designs employing solid-state inverters to regulate the AC output frequency to 60Hz, thus constant engine speed is not mandatory. I might add that the EU2000i manual still says “Engine speed = 4,300-5,000 rpm” (or 4,650 +/-350 rpm) …..which is reasonably constant in my book.
But my essential technical point here is that the Volt engine/generator combination can actually be operated at essentially a constant rpm (2,500 +/-250 rpm, say) while the Volt’s control electronics can vary its output power supplied to the battery from its maximum (~50Kw) to ZERO with very little loss in overall efficiency. Exactly what rpm range GM decides to use will certainly involve, as you say, a number of tradeoffs —including economy, roughness, noise and of course durability. It will be interesting to see what they wind up with.
In any case, I suggest we all stop speculating further about what they’ll decide.
July 27th, 2008 at 11:48 pm
Brian good question. I don’t have the spec answer for you but I BELIEVE part of the answer lies in the fact that running all accessories, high speed, up a mountain, at night would probably require a larger engine that you mentioned.
Now that said maybe the draw back would be that you have to pull over and let the battery recharge halfway up the mountain if you were doing that. AND that might not be a concern to 95% of the drivers. But GM doesn’t want limitation issues like that making it into the media so they go with an engine that wont ever have those issues.
That said it still would take an engine as large as a good sized motorcycle engine to maintain the Volt at highway speed. So although this may sound big enough it isn’t because you want the engine running in it most efficient rpm range when doing this, therefore you scale up the engine so that it can run without a big strain.
So long story short, an engine just big enough is not what you want as the range extender.
July 28th, 2008 at 12:35 am
For a engine/generator some where down the road the free piston engine might fill the bill.http://www.freepistonpower.com/FP3.aspx
July 28th, 2008 at 1:23 am
#208 Nasaman
You are so right on the inexpensive home type generators that most are familiar with. The 120 and 240 vac 60 hz. most all of them turning 3600 rpm.
But with the newer split stator alternator style they only turn 1800 rpm to get the 60 Hz. The draw back being they require twice the tourqe to turn them.
It has been my findings that when driving a AC drive motor that the input Hz to the motor controller can very greatly as long as it stays with design specs for the controller. It is the voltage in this case 380 volts AC the wattage be it 50 KW or 53KW and the sine wave from the controller that controls the tourqe and rpm of the drive motor.
As I said this is just what I have Found. Others may have more input on this.
GOOOOOOOOO GM
GOOOOOOOOOOOOOO VOLT
July 28th, 2008 at 1:28 am
#227 Nasaman – you won’t get 53 kW out of this engine at 2500 rpm. The ICE will not run at constant RPM. Repeat, the ICE will not run at constant RPM. It will run near redline (near 5000 RPM) up long mountain highway grades but will run 2000-2500 RPM in normal highway driving. It may run as low as 1000 RPM in some scenarios.
RPM changes will be very gradual. Rapid RPM change is bad for efficiency. As Larry Nitz says the battery will handle dynamic response.
#39 DA – your math is wrong. Volt ICE will not put out 50 kW in normal circumstances (only the long mountain grade scenario). Volt ICE peak power is 53 kW. Optimum ICE efficiency is usually around 40-50% peak RPM and 85% BMEP or about 40-45% of peak power. Thus Volt should hit peak efficiency at 21-24 kW. But Atkinson cycle engines achieve near-optimal BSFC down to 20% of peak power (approx 11 kW) as long as you allow RPM to drop to match the load.
Volt ICE will run with open throttle at whatever RPM best matches the road load. If battery SOC falls too much (e.g. after uphill freeway merge) ICE will gradually increase RPM/power to bring SOC back up. If SOC climbs too high (e.g. exit freeway and brake to stop at bottom of hill) the ICE will shut off for a while.
One reason they need a quiet, low vibration ICE is because RPM will not follow vehicle speed as in a “normal” car. People complain about this with CVTs all the time. It’ll be even worse in the Volt as RPM may go to zero at highway speeds. You don’t want people noticing all this “weird” behavior. This works against the 3cyl turbo.
July 28th, 2008 at 6:29 am
The battery will run down to 35% before the ICE comes on. Previously it was 30%. Does that mean all electric will be less also.
July 28th, 2008 at 7:06 am
#232 Ed asks: “The battery will run down to 35% before the ICE comes on. Previously it was 30%. Does that mean all electric will be less also.”
————————————————————————————–
No. The new battery swing is specified at 35-85%. Previously, it was 30-80%. In either case it’s a 50% swing range, so usable electrical storage is the same.
July 28th, 2008 at 7:16 am
#231 doggydogworld,
Yes, this all makes sense and I agree with everything you say.
But do we know for sure that it will be variable RPM?
A third possibility some have mentioned is a defined set of different constant RPMs (e.g. low, medium, and high). The engine, exhaust, etc. could be tuned to these different RPMs. In addition, the transition from one to another could be slow to keep efficiency high.
Also, last summer, GM stated that:
“Interestingly, the motor will likely be programmed to increase rpm when you step on the gas and quiet down when you stop to “simulate” the driving effect people are already used to. This will avoid the sudden unexpected ons and offs.”
I think the way you describe it in post #231 makes the most sense, but who knows for sure?
July 28th, 2008 at 7:18 am
231 doggydogworld….. You’re absolutely right that this 1.4L engine won’t produce 53 KW (72HP) at 2,500 rpm, but that its best nominal operating rpm should be on the order of 45% of its peak power rpm (or roughly 2,500rpm). And I’m glad you pointed out the tough tradeoffs GM faces as a result of the counter-intuitive sounds the engine will sometimes produce that don’t relate to vehicle speed.
But I want to reiterate these points that I’m afraid some here don’t fully realize….
1) The Volt’s control electronics should be the primary means the Volt’s battery charging rates are controlled, not engine rpm; engine rpm changes should be secondary (and limited to those fairly rare occasions when the battery discharge rate is extremely high such as long, fast mountain climbs)
2) Nearly 100% of the time, the engine rpm should be limited to a fairly narrow band near it’s highest efficiency rpm; long, fast, steep mountain climbs that occur when the battery is also near its minimum SOC should be a rare exception —at most other times the engine rpm should remain relatively constant & change VERY gradually
In other words, battery charging should normally be controlled by the control electronics in a manner allowing the engine to run at its a) highest efficiency and b) lowest noise levels. Charge control should be accomplished by the control electronics, NOT by the engine rpm.
(I’ll also add that extraordinary sound insulation such as an elastomeric/alum/elastomeric sandwich effective at very low frequencies should be considered,* as I’ve suggested in several previous threads, to minimize any “weird”, counterintuitive engine noise in the cockpit you correctly describe as not unlike the noise a CVT belt-cone transmission produces).
Of course, as you say, the engine will be shut off in cases such as exiting a freeway and braking to a stop at the bottom of a hill whenever the SOC climbs too high as a result.
*I added this inexpensive but highly effective sound-absorbing material inside the motor box of my 4 cyl Chevy-powered Mercruiser —my neighbors accuse me of having a nearly-silent “stealthy” boat; they tell me it can be pretty “spooky” at night when I shut off all running lights & use the GPS to navigate!
July 28th, 2008 at 8:44 am
@235 Nasaman – your elastomeric/alum sandwich sounds cool.
You’re right near-redline operation will be rare. I don’t know if they’ll run a narrow RPM band “nearly 100% of the time”, switch between several RPM settings tuned for optimal airflow as DaveG suggests in #234 or continuously vary RPM along an optimal path as Prius does.
PS. DaveG thanks for the quote about programming RPM to simulate normal gas pedal response. I missed that one.
July 28th, 2008 at 9:01 am
I think they should have a button inside the car that when pressed the ICE runs until the car is charged…
So when you are at the Mall or what ever you will have a full battery when you get back that was charged at the Maximum efficiency with gasoline instead of driving and charging.
So while the car is outside locked up and charging and you are in the Mall the 50kw goes straight to the battery, instead of when you hop back in the car and start driving 25kw to get you home and 25kw to the battery. Why not all 50kw to the battery, less time the engine runs less consumption. Of course the ICE turns off when the battery is charged. That is why i said a button to make it optional… (The reason for this is not everywhere you can plug your car into a socket)
July 28th, 2008 at 9:02 am
If a fledgling company like Tesla can build an incredible vehilce without an engine, that goes 240 plus miles, where is GM missing the boat, other than they still want to sell engines that burn gasoline. I too am getting a maintenance headache. I would never buy one of these hybrids. It is cheaper to keep my gas guzzler, than to buy a fancy engine driven car, they want you to think is better.
Come on, GM, get into the electric car business, or get out of the business. Quit losing money, and build a pure electric plug-in so we as americans can get off the oil and gasoline wagon, and don’t say it cant be done.
rw
July 28th, 2008 at 9:03 am
#235 nasaman
Since we’re all guessing at how the Volt’s engine RPMs will be regulated, here’s another possible scenario:
1) For low driving speeds, perhaps 30 MPH and less, the gas engine’s RPMs will vary between 1000 and 2500 RPMs according to the power demands of the vehicle.
2) At speeds between 30 MPH and 75 MPH, the engine will hold a fairly constant 2500 RPMs for maximum efficiency, but will vary the throttle according to varying load.
3) When driving at speeds above 75 MPH or up steep hills, the gas engine’s RPMs will vary between 2500 and perhaps 5000 RPMs according to power requirements at any given time.
Of course, the exact number of RPMs and MPH in the scenario could change, but the concept remains the same. The engine runs constant RPM throughout the range of typical power demands, but switches to variable RPM when power demands are very low or very high.
To me, this scenario seems like the best of both worlds. A constant RPM is used to increase efficiency throughout the the majority of normal driving speeds. Lower variable RPMs are used at low driving speeds to keep the car quiet and prevent the engine from cycling on and off frequently. Higher variable RPMs are used in cases that require more power. Seems like a win-win…
July 28th, 2008 at 9:12 am
#238 realtorron says:”Come on, GM, get into the electric car business, or get out of the business. Quit losing money, and build a pure electric plug-in so we as americans can get off the oil and gasoline wagon,…”
————————————————————–
I totally disagree.
Yes, Tesla has started with a $100K sports car because it’s easier for a small company to start making money in that market. But Tesla’s 3rd generation $30K “Blue Star” sedan will have a gas engine range extender just like the Volt. A series hybrid (a.k.a. E-REV) is simply the best design for this price point.
Given that we drive long trips a few times a year, I would never buy an electric vehicle without a gas/E85 range extender.
In addition, history has shown that the best way to change a market paradigm (e.g. gas to electric) is through migration. In other words, you offer a product that supports both paradigms, and the public then transitions to the new paradigm. The pace of this transition depends on the viability of the new paradigm.
If you tell people to just switch overnight, many people will resist, and the transition will take longer. So the fastest way to get to driving on electricity is through cars like the Volt.
July 28th, 2008 at 9:16 am
If GM doesn’t get on the ball and build a better all electric car, the Chinese will do it (They already have), and will import them, and control our automotive market. Lets stop the crap, and start building what America needs. I swear, the majority stockholders of GM are all oil company executives, and this is not funny, nor smart.
July 28th, 2008 at 9:23 am
With the new technology that has recently been developed the new heavy capacitors will be able to charge the batteries within an hour or less. This will allow for long driving time, with short recharge time. With a small wheel driven generator that feeds the capacitors, we would not need the grid. By the time the volt comes out, they will have built a better mouse trap.
July 28th, 2008 at 9:35 am
#242
Expanded:
Just drop the whole battery and ICE…
Just use some Ultracapasitors… 500 mile range.. 5 minute charge..
Who needs anything else? Even if you only get 1/2 the range and double the charge time? so 250 miles, 10 minute charge up… Wouldn’t you still buy it?
Source: http://www.msnbc.msn.com/id/20533045/
July 28th, 2008 at 10:18 am
The idea of the Volt and electric drive was to provide a smooth and quiet ride. I did wonder how a 3 cylinder–especially with a turbo with its assocated sound–would ruin the “experience” of driving such a car. A turbo makes sense in a “traditional” car like the upcoming Chevy Cruze where the turbo whine may even be considered sporty and desirable.
July 28th, 2008 at 10:36 am
#243 brandon asks: “Who needs anything else? Even if you only get 1/2 the range and double the charge time? so 250 miles, 10 minute charge up… Wouldn’t you still buy it?”
————————————————————————————–
I wouldn’t buy a pure EV with a 250 mile range.
If the EEStor Ultracap technology works out to be as cheap as they say, that would be great. It would mean we could have E-REVs with 80 – 100 miles of range for less money.
The problem with a pure EV is the quick charge filling stations. Changes to the infrastructure will take time. It took around 50 years to build out our current infrastructure of gasoline filling stations. It will take at least 20 years to fully convert that over to electrical quick charging stations, and that’s if the advantage is crystal clear.
To me, the advantage of driving the daily commute on electricity is crystal clear, and it doesn’t require any new infrastructure. Just plug in at home and charge overnight. Electricity is 3-4 times cheaper than gas, and plugging is is less hassle that going to the gas station. What’s not to like?
But for longer trips, I don’t see a clear advantage of quick charging over E85 or bio-diesel for the driver. Converting a gasoline pump to E85 or bio-diesel is relatively cheap and easy, so this would have a strong advantage with filling station owners.
Making a new car that uses new technology is common. People expect it. People are also fairly used to plugging in their cell phones at night, so plugging in your car won’t be that hard to accept. But asking gas station owners to pay huge amounts of money to rip out their gas pumps and underground tanks, and replace them with quick electric charging pumps and large underground batteries – that will be a TOUGH SELL!
July 28th, 2008 at 11:14 am
#231 doggydogworld.
Yes, yes i comprehend what your saying but i don’t now which one of us doesn’t have the facts straight (or both of us for that matter).
I have no prob with the 4-banger v. the 3-banger. Its a fine engineering choice so long as they comfortably fit the larger displacement in the compartment. Saves cost? Great! This article aslo implies that the gain from Turbo-Charging didn’t seem as significant as originally spec’d. Fine, sh*t-can the turbo! My concerns focus on optimal engine sizing overall.
The governing question is: how much horsepower does the NA 1.4L produce? I did some digging and found:
“Dubbed the 1.4 Twinport Ecotec, the Euro-spec NA version makes 90 horsepower at 5600 RPM, 92 lb-ft of torque at 4000 RPM, and gets 38.5 US miles per gallon in the combined cycle.”
If i read this correctly the engine peaks at 90hp (67.5 KW), and has peak torque at 4000rpm. Using our math, (maximum FE occurs at 50% peak), yields a maximum FE at 45 hp (33.75 kw). That places us close to what the output OUGHT to be to maintain steady-state 65mph open road driving of 15 KW, plus some margin say 5kw… However, Its clear to me this engine is over sized.
All the volt needs is a 55hp (40kw peak) ICE at most. This would correlate to a 0.85 L displacement, assuming HP scales linearly with displacement (which i understand it doesn’t). But you get the point, a lighter engine, lighter genset. Why is this important. B/c to achieve maximum fuel economy in range extended mode you want the ICE to operate at maximum efficiency (we define this as roughly 50% peak output).
BUT, if that output level is comfortably above AVERAGE hwy driving demand load, you are unnecessarily cycling the battery.
I’m pointing that this is a trade-off with over-sizing the ICE, which either comes with the Fuel Economy by pushing the engine into non-steady state operation, OR placing extra wear on the battery stack but getting maximum FE.
It is important to note, that extra wear on the pack is an important concern, as it will result in a faster decline in AER. A shorter battery stack service life, may result in less than optimal fuel economy over the life of the vehicle, and less customer value (shorter service life, resale value etc.)
I may catch some flack for this, but has any one heard of built-in obsolescence? Nah! My guess is GM just wants to build a car that hauls-ass at 110 mph in range extension mode…
Skeptically,
#DA
July 28th, 2008 at 11:31 am
Check this out:
http://media.cleantech.com/2644/zenn-gearing-up-for-eestor-powered-car
ZENN is producing cars with this Ultracapacitor in 2009.. 250 miles with 5 minute charge.. 80MPH… Might be interesting to watch.. Maybe a change of plans GM?
July 28th, 2008 at 11:39 am
OK, OK. 3 cyl, 4 cyl, turbo, schmurbo.
Just get us the !@#$%^ Volt before it’s too late!
July 28th, 2008 at 12:05 pm
How can you come up with sales figures when you havent even finalized the design????
Looking like a PR stunt more every day…..Cmon suckers buy some GM stock!
July 28th, 2008 at 12:35 pm
245 dave g says:
(begin quote)
But asking gas station owners to pay huge amounts of money to rip out their gas pumps and underground tanks, and replace them with quick electric charging pumps and large underground batteries – that will be a TOUGH SELL!
(end quote)
Why would they rip out their gas pumps and underground tanks? Why have underground batteries??? Leave the pumps and tanks there…all you would do is have an additional device at the gas station with some high voltage electronics (or whatever) that the electric car hooks up to. I’ve never heard of an electric car requiring anything more complicated than a clothes dryer-grade electrical outlet. Am I missing something?
–Brian
July 28th, 2008 at 12:39 pm
#246 #DA says: “The governing question is: how much horsepower does the NA 1.4L produce? I did some digging and found…”
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The Volt will likely use an Atkinson cycle on the gas engine. This will make the peak horsepower much less, but will increase the efficiency dramatically. Note that the Atkinson cycle is used in most hybrids.