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%]
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Related posts:
- GM Has Decided on the 1.4 L 4-Cylinder Engine as the Range Extender for the Chevy Volt
- GM CEO Confirms 4-Cylinder 1.4 L Engine Being Considered For the Volt’s Range Extender
- Has GM Increased the Size of the Chevy Volt’s ICE from 1.0 L to 1.4 L, and Cylinders From 3 to 4?
- GM VP of R&D Suggests Natural Gas Chevy Volt Range Extender
- Nissan CEO Ghosn: “I Don’t Want a Range Extender”
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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.”
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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.”
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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 cl