AND 
Chief Powertrain Engineer Pleased With Chevy Volt’s Charge-Sustaining Mode
Volt in Tennessee
I had the following discussion with Alex Cattelan who is the Chevy Volt’s chief powertrain engineer. She has a very deep understanding of how the car operates and recently drove in a fleet of integration Volt prototypes through rugged mountains of Knoxville Tennessee.
Do you feel the charge-sustaining (CS mode) experience is now pretty solid and are you pleased with it?
We are definitely pleased with the level of progression we’re at. We are right on track to where we need to be in terms of the next stages of development we need to do to meet our target. Is it commercial right now, no, but that’s why were taking the time to get it to be commercial. Does it have the capability of being commercial, absolutely. We’ve proven that to ourselves.
We just took our leadership through a test drive in Warren (Michigan) and comments are that they cant tell when the engine is coming on or off. Those are the kind of things we like to hear.
You drove the IVs around the mountains of Tennessee. What about those big hills and the generator. It sounded like it drove very briskly powerfully and effortless is that true?
Yes, absolutely. Some of our control capability to utilize the battery, the engine, and the motors and to be able to optimize for high load and low load situations we’ve been working on developing that stuff for the last year and half an I couldn’t tell you how happy I was when I was in Knoxville because that’s when I had the opportunity to see it all come together. A lot of those bits of software all came together on one trip and it was a joy to drive.
So you took it up some steep hills and mountains?
Absolutely. We were in the Cherokee area taking it up through those hills and a lot of situations following it. It was a very touristy area. Following the speed of traffic, absolutely no problem, and where I had opportunities I certainly like to push the limits of the vehicle, and we did on those mountains, and I could not get it to degrade in performance.
That’s in charge sustaining mode?
Certainly in charge depleting, we have no issues because we have battery power, I’ve got it all at my fingertips. Now in charge sustaining we know that the engine power is slightly less than the peak vehicle power but we have controls ways to manage that and to utilize the engine in conjunction with the battery to get a little bit of extra power when we need it, and replenish it back when we don’t.
I know the battery runs down to roughly the 30% level before for the engine comes on. Is that 30% itself the whole potential buffer band?
We certainly don’t utilize the full 30% but there’s a portion of that that we utilize as a buffer.
You wouldn’t go to zero ever?
No. When the engine cannot meet peak load requirements we’ll suck a little bit out of that buffer and as soon as we have a situation when we can, we’ll put it right back in. All the controls that we work do that to optimize not only the driveability but the efficiency as we’re doing it, NVH (noise vibration harshness) as we’re doing it, the total driving experience as well as to protect the battery from a life experience. This is what allows us to give really good warranty life on our batteries as we’re doing I all in a controlled fashion.
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November 12th, 2009 at 9:20 am
OK!!!
Let get Lyle that CS mode drive!
November 12th, 2009 at 9:32 am
Very interesting post. Sounds like a great ride. I can’t wait for the Car and Driver etc. reviews of full test drives. I imagine they will be very favorable.
But then again, without knowing the exact volume of the gas tank I have no option but to dismiss the Volt as vaporware. Pfffttt….
November 12th, 2009 at 9:34 am
I’ve had my 2 cups already….but this sentence makes my head hurt.
I’m confused (it happens a lot)…..
“Now in charge sustaining we know that the engine power is slightly less than the peak vehicle power but we have controls ways to manage that and to utilize the engine in conjunction with the battery to get a little bit of extra power when we need it, and replenish it back when we don’t.”
Will this car have less power when the engine is on??? I didnt think that was going to be an issue…battery power is battery power isnt it???
November 12th, 2009 at 9:34 am
Lyle brought out some key points which sound pretty good.
1. Engine is rarely noticeable.
2. Battery buffer zone begins at 30%
3. ICE is undersized.
I am already looking for the next version of the Volt. If there is an SS version, it will most likely have a larger ICE to maintain the performance characteristics of the vehicle.
I can still see a time when you may end up in a position of 20% battery left, buffer zone depleted, and still have some horsepower intensive road left to drive. The drop in available power would most likely be felt. I would rather not have that compromise. Additional horsepower would not add to the weight significantly.
Just my thought. Fire away.
November 12th, 2009 at 9:35 am
I don’t think that she said “coupling” one time in this interview. That’s turned out to be a very confusing word for many folks. The Volt employs electrical coupling between the generator and the traction motor but it does not employ mechanical coupling between those two components, just as the original design proposed.
It sounds like the Volt is able to come up with the needed hill-climbing power by slightly dipping into the less-than 30% capacity of the battery when needed. It sounds like they were always able to find an opportunity to recharge the battery up to 30% before any significant depletion had occurred. That’s great news. It means that the Volt will be an effective highway car as well as an idealic city car. Can’t wait to get one!
November 12th, 2009 at 9:35 am
Protect the battery from a “life experience?” LOL!!
I’m glad things are coming together and really hope I can at least get a test drive.
November 12th, 2009 at 9:40 am
Very nicely done, Lyle. Great article.
—-
I was in Cherokee back in August. It is a very touristy place with quite a bit of traffic. The Smoky Mountains there are very beautiful and hilly with some steep parts and 180 degree turns.
—-
I am excited to hear that no one can tell when the engine goes on.
That is very cool.
—-
I would love to know how many battery miles she was able to get from the car while doing the drive through the mountains.
November 12th, 2009 at 9:45 am
(click to show comment)
November 12th, 2009 at 9:45 am
It certainly sounds as though the Volt will provide an excellent driving experience. This is an example of what I meant by “the better mousetrap” comment I made a few posts ago. If the Volt can provide an exciting driving experience…AND not use a drop of gasoline for 40 miles…it will certainly generate a lot of interest…especially as the price comes down due to improving battery technology…and the price of gas continues its unabated climb.
LJGTVWOTR!
November 12th, 2009 at 9:48 am
Great!! Good work GM
lets us wait
November 12th, 2009 at 9:54 am
This is exciting and inspiring. In all the technical discussions with GM people for as long as I can remember, there has always been positive and obvious enthusiam. This is a concrete testimony that the Volt is an idea whose time has come and, as we have dared to believe, will transform the automotive industry. Go Volt!
November 12th, 2009 at 10:00 am
#3 “Will this car have less power when the engine is on??? I didnt think that was going to be an issue…battery power is battery power isnt it??? ”
No, it won’t. when on battery power alone, the maximum the motor will draw is 112kw, the battery can easily supply this. when the engine is running, the maximum motor draw is still 112kw, with the genset providing 53 kw and the battery supplying 59kw. How long could the battery supply this 59kw? well, the battery capacity is 16kwh (or 960kilowatt minutes). if we make an assumption (purely a guess) that after the 30% SOC is hit and the engine starts there is a further 10% allowable usage (dropping SOC to 20%). that 10% is 1.6kwh or 96kwm. that means there is 59kw available for one minute and 37 seconds.
Under what conditions will you require 112kw?
A) You are travelling at 145mph
B) You are accelerating at full throttle for over one minute 37
C) You are hill climbing an extremely steep gradient at high speed
will any of these ever happen?
A) No. Vehicle speed is restricted to 100mph, drawing only 53KW
B) No. I’m confident you’ll hit 100mph in less than 1:37, at which point your power requirements drop back to 53kw. when you then slow down (eventually you’ll hit a junction, roundabout, traffic, whatever) the genset will continue pumping out 53kw till you get back to 30% SCO.
C) Potentially, though my instinct tells me your average driver will not have a problem with this. even if it -does- happen on some mega steep, mega long, mega straight hill, all the ICE cars round you will be slowing down as well, so it would be behaving like a normal car.
Hope that clears it up a little for you.
November 12th, 2009 at 10:02 am
I guess this confirms what I was wondering in the last thread:
“Do you feel the charge-sustaining (CS mode) experience is now pretty solid and are you pleased with it?
We are definitely pleased with the level of progression we’re at. We are right on track to where we need to be in terms of the next stages of development we need to do to meet our target. Is it commercial right now, no, but that’s why were taking the time to get it to be commercial. Does it have the capability of being commercial, absolutely. We’ve proven that to ourselves.”
That is pretty clear. Work on the CS mode is not finished. I feel confident that they will get it done in time for next November, but the clock is ticking…..
This is THE big item to make the Volt a success. Take your time and get it right!!!!
November 12th, 2009 at 10:04 am
Way Off Topic:
But very interesting…..
VW overtakes Toyota as the #1 automaker.
http://www.carblog.co.za/2009/11/10/volkswagen-porsche-now-worlds-number-one-auto-maker-toyota-gets-2nd-place/
Their time at #1 was not all that long, was it?
November 12th, 2009 at 10:04 am
“We just took our leadership through a test drive in Warren (Michigan) and comments are that they cant tell when the engine is coming on or off. Those are the kind of things we like to hear.”
Those are the kind of things I like to hear too!
Great interview Lyle. Keep them coming.
November 12th, 2009 at 10:04 am
Along with the “Life Experience” for the battery, I hope GM finds a way for the battery to avoid a “Mid-Life Crisis”
I still want one badly.
Excellent work Lyle, these little nuggets of info really make my day.
November 12th, 2009 at 10:08 am
PE, Hermant, I think you are worrying the Pikes Peak bone a bit too much, needing nearly full throttle for that long is something that will seldom occur. If you are in CS mode and you hit the Pikes Peak part of the road, the car will use the buffer by drawing the 30% down to 20%, which would be about 4 miles of full throttle or 5+ miles of 3/4 throttle, which is more likely. Every time you let off the gas, the excess ICE generated power will be building the depleted battery back up closer to 30%. You would have to have an awfully long, steep road to deplete the battery that much without allowing the generator any time to recharge. If the buffer is from 30% down to 15%, then I just don’t see it as being an issue at all.
Now if you are towing a personal water craft, maybe then you will have an issue with the buffer being too small.
I don’t think the ICE is undersized, in fact, if the Volt II has a smaller ICE option, I would probably opt for that because it would get better CS mileage, and I doubt I would ever drain the buffer completely so I wouldn’t have a downside.
November 12th, 2009 at 10:10 am
If you are on a long trip, or on a long grade(s), why even bother with trying to stay near 30% SOC? Get up as high a charge as you can while you can and then shut the ICE off or bring it down to lower rpm. You only want to get to 30% when you pull into your garage (or another charging point).
It’s more important for the Volt to know where it’s going and the intervening changes in elevation it’s going to encounter, than to put a lot of effort into this ‘hunting’ around 30%. Perhaps you could loosen the 30% restriction and add to the AER without degrading battery life by charging up for the expected usage given the destination.
Also, it’s curious that it’s not ‘commercial’ at this point – odd language – is something awry?
November 12th, 2009 at 10:13 am
The “vaporware” Trolls have been eerily quiet for weeks…
Either Toyota has quit paying them minimum wage to harass this site, or the Truth has set them free!
Go VOLT! Get to the showrooms on time!
November 12th, 2009 at 10:21 am
If I understand you here, you’re not likely to have any control over the amount of charge you have, except within 40 miles of an electrical outlet. The Volt will decide when to “shut the ICE off or bring it down to a lower rpm.” You cannot use the ICE to deliberately charge the battery pack above 30% SOC.
If there is a button or function that forces Charge-Sustaining Mode to come on regardless of SOC (if higher than 30%), this could accomplish pretty much the same thing (hold more battery charge in reserve). There has been a lot of speculation here on whether or not this feature will be offered.
I agree with most commentors to this point; you will encounter a loss of power under circumstances so rare as to be practically impossible for the vast majority of Volt drivers.
November 12th, 2009 at 10:23 am
I think Lyle finally blocked “no-name” and maybe a couple of other repeat offenders.
THANK YOU, LYLE!!! (In addition to the usual thanks for providing this blog).
November 12th, 2009 at 10:24 am
Why are people making up their minds of the performance in CS mode when they haven’t been able to test it for them selves? Drives me crazy. She said it would be slightly less powerful. She did not say that it would feel like a 1.0 ltr automatic with the AC on. I don’t know either way but sitting here talking like you already drove the car up a hill in CS mode is ridiculous.
November 12th, 2009 at 10:26 am
This article sounded good to me. I guess the average driver rarely sees a degradation in performance.
I cant wait to get mine.
Go Volt go.
PS a quick shout out to my fellow divers
November 12th, 2009 at 10:41 am
I realize that GM does not want to use the ICE to charge the battery to a level greater than 30% SOC. Instead, they want to wait until a connection to the grid is available. That’s understandable. BUT, if they find during their testing that a buffer of 30% SOC is not sufficient to assist the 53kW genny in extreme conditions (e.g. mountainous regions), I hope they consider adjusting this strategy. By that I mean I hope they consider increasing the buffer a bit, possibly to 40%. Whatever it takes to cover all scenarios.
That would mean that you would still charge from the grid in the range of 40% SOC to 80% SOC. Yes, this is a compromise, but it’s still respectable. And it’s worth it in order to avoid the Volt getting a reputation of being a “dog” in CS mode IMHO.
And this does not suggest GM would need to change the lower threshold of charge depletion (CD) mode from 30%. They’ve determined that is a safe level to discharge to so that is fine. Just consider charging the battery at that time back up to 40% to increase the buffer.
And keep in mind that this entire issue is moot when in AER mode.
November 12th, 2009 at 10:46 am
Not sure they want a larger engine do you really need to exceed the speed limit in charge sustaining mode? Bigger engine unless turbo = more weight + less efficiency. If you can get more power without a cost in weight or efficiency that would be OK. My goal woudl be to use the ICE as little as possible anyway.
November 12th, 2009 at 11:01 am
Flaninacupboard….I thank for that response at #12…
Even with your guesstimates, I actually see where my simple brain has lead me astray on this. I was actually under the impression that the genset was only ever pumping charge back into the battery. I didnt know that it becomes a ‘team’ effort to power that motor that drives the wheels once we hit the 30% SOC. I thought that motor that drives the wheels was drawing power from the battery exclusively.
I should go home now ’cause I think I’ve already learned something today…
November 12th, 2009 at 11:15 am
The 30% buffer level of the battery is computer controlled anyway. Seems like this is something that could change on the fly based on your location. The car will, I’m sure, have GPS and On-Star, so the car could notify GM through On-Star if it reaches a critical level and uses reduced power (and data about it’s power usage on the roads it has traveled since it hit 30%). Over time, GM could know what power it takes on average to drive any road and could adjust via On-Star what the buffer percentage needs to be as the car drives along any particular stretch of road to end up at 30%. So then maybe you have some loss of power for the first couple of years, but over time, that disappears.
November 12th, 2009 at 11:18 am
From an engineering perspective, all she is saying is that a battery at 30% SOC produces a lower voltage, hence less power, than one at say effective 100% SOC. That is a natural phenomenon. As anyone who has used a flashlight knows; as the batteries discharge, the light from the flashlight grows dimmer.
But they have a means through electronics, or simply generator overvoltage, to boost the voltage, as if, the SOC was was at effective 100%, so the traction motor has full voltage, and hence full power capability.
November 12th, 2009 at 11:18 am
Great report, Lyle.
November 12th, 2009 at 11:18 am
I believe it would be good to have a rate-of-discharge sensing circuit that would start the ICE on a sustained high discharge rate that would indicate a long grade. Maybe this is already built in one of the the drive selector positions. Why wait for the 30% point? Also based on this recent power usage it would be good for the ICE to take the charge back up further than the 30%.
November 12th, 2009 at 11:18 am
To help put this “when to run / not run the Internal Combustion Engine” issue into perspective (especially for any newbies who may be reading), consider it economically:
Depending on where you live, and when you plug in, your local electric utility will give you a price per kilowatt hour of a few cents (between 6 – 15).
The Volt’s on-board generator can be considered a very small electric utility that you own and operate yourself. You cannot possibly match the cost per kilowatt hour of your local utility, because you can only run your generator on gasoline or E-85: your local utility can use coal, nuclear, hydro (etc), and has economies of scale going for it that are unavailable to you.
I have no idea what the actual cost per kwh would be using the Volt’s generator, but even at current gas costs it’s likely to be at least 10X higher (and much more than that at the $4 a gallon price likely to return when the economy recovers).
SO … does it make sense to pay 1.00+ a kwh to recharge a battery which could be charged at 10 cents per kwh?
(Now, let some engineer types who can do math before noon hop in with a more informed SWAG on the Volt genset’s electricity cost per kwh; but I do believe it will be fairly high compared to the plug).
In the course of driving, some recharging of the battery pack’s small “buffer” allocation is inevitable, but no doubt the control software keeps this to an absolute minimum.
November 12th, 2009 at 11:19 am
A: I think everyone knew that it’s limitted to 100MPH.
B: You underestimate the human nature of pushing to the limit. Many people will try it. I bet our frequent drunk poster will.
C: You must not consider the population of suburbianites that go skiing or play in the snow or camping in the mountains or “over the hills and through the woods to gramma’s house we go…”
More people will push each aspect more than you think. To think nobody will is just nieve.
November 12th, 2009 at 11:21 am
I think the future holds a smaller genset, but a larger traction motor and a battery with twice the energy density. This would allow greater AER and a larger buffer to manage prolonged high power demand – greater than max capacity of genset. It will be called Voltec 2.0
November 12th, 2009 at 11:29 am
The most important of all the statements was completely over-looked. Non- casual observers, but observers nonetheless, had trouble identifying the onset of ICE engine generator operation, and its discontinuance.
After all the suspicions that there was a “grim problem” it turns out to be a non-event, If the Prius can do it in a much more difficult situation, without too much jerk and surge, than a mechanically disconnected ICE initiation can surely be made imperceptible, and it apparently has been achieved.
Incidentally, I had my first occasion to drive in a Prius and I found a constant surging in operation. Is that normal for all Priuses or was the the one I drove having a problem? While not totally disturbing, it was noticeable. It felt like the driver were constantly altering the accelerator pressure, constantly “goosing” the throttle.
November 12th, 2009 at 11:31 am
Great update – sounds like all is proceeding as planned. Any word on when the next build starts?
November 12th, 2009 at 11:35 am
She seems quite sure that in time all the remaining problems will be resolved. In development there are problems you don’t know how to fix or if you can fix them, and those that you know you’ll be able to fix, even if you don’t know exactly how. Seems like she believes the outstanding problems fit in the second basket.
When thinking about dipping below the battery’s 30% SOC and how the buffer might be replenished, keep in mind that in driving hills in most situations you go down hills as well as up them. The former provides the opportunity for regen to recapture some energy. IOW the gen-set isn’t the sole means of recharging the battery. With an EV like the Volt you always have the completely “no cost” opportunity of turning kinetic energy into stored battery power through regen. (How cool would it be to start down a hill with 1/8th of a tank of gas and get to the bottom with 1/4?).
November 12th, 2009 at 11:39 am
What your talking about is a deadband. The official deadband has not been released to us by the engineers. They cannot pick one number, say 30%, and have the engine and generator constantly turning on/off fighting each other. I doubt the bandwidth will be 10% as you suggest, but I could see them going as far as +- 5%
November 12th, 2009 at 11:40 am
You dont want the engine or catalytic converter to cool off.. you want to run the engine at that precise throttle point to keep the battery at 30%. It would be more efficient to run the engine at full bore and then shut it off, but noise would be high and pollution bad until it warmed up. You dont want to end up with a battery charged more than 30%, that would be wasteful.
November 12th, 2009 at 11:41 am
There have been many here who has spoken about “Mountain Mode” Which would really be the same as your 40% suggestion.
A simple button could be used to tell the car to use a bigger buffer for this part of the trip.
However personally I’d like the NAV system tied into the battery management system so the car would “know” there is a big hill coming and it could automatically cache a little extra charge to deal with it.
Although I still think this whole issue is likely getting blown way out of proportion.
November 12th, 2009 at 11:44 am
The behavior was due to the driver not the car. You get better mileage if you do it this way so it’s something of an advanced technique.
As for all the questioning a few months back about whether CS mode was presenting serious issues, that was mostly a function of people not being familiar with development. It never seemed like that big of a deal. However, note that Alex said all the pieces — and doubtless there are many — only recently came together. I’d say that until this happens you can’t rule out the possibility of serious issues. Rather than being misguided the speculation was simply premature.
November 12th, 2009 at 11:51 am
Your point about the catalytic converter point is of major importance. Virtually all particulate emissions occur on cold starts. Once the engine is warm the converter eliminates them. Consequently, GM engineers have been clear from Day One that once the engine kicks in there is little to be gained from cycling it on and off (other than of course briefly at traffic lights), and that once it comes on it should stay on until the user has a chance to recharge the battery from the grid.
November 12th, 2009 at 11:56 am
I REALLY like your analysis. Thanks. +1
November 12th, 2009 at 11:58 am
I agree. Along the lines of the NAV to allow a higher SOC, I think there should be a user selectable option to have the genset charge the batt pack a little higher if the driver knows the destination will not have a place to charge. Say like if you are staying at the “Bates Motel”, you know what I mean? Or if you’re staying high up in da hills away from the inlaws.
November 12th, 2009 at 12:02 pm
IMHO, I don’t care if you can’t feel or hear the genset ICE. Personally I’d prefer to feel it so I know it’s working the way it’s supposed to. It helps me better understand MY VOLT!
The ICEAge is over, Embrace the VoltAge!!!
November 12th, 2009 at 12:09 pm
Its normal, the car is constantly adjusting the throttle to get it just perfect.. Turn the radio on and you wont notice it.. I understand cars equipped with CVTs do the same thing.
November 12th, 2009 at 12:13 pm
I noticed the same thing on the Rental my wife had. It’s most likely normal. I didn’t think it was too noticeable.
November 12th, 2009 at 12:19 pm
Lyle, please consider some articles along the line of “What dealerships are doing to prepare for the Volt” and “What we can do to let the dealerships know of our interest”. Time to let them know that there are CUSTOMERS out here.
November 12th, 2009 at 12:19 pm
The genset size is driven by the spec that the Volt can go up to 100mph when the battery is depleted, CS Mode.. also perhaps by driving with a maximum weight load up a continious grade.. and also by having a bigger engine turning lower rpms that are not noticeable to the driver. I dont care how good a muffler is, if your small ICE is doing 6000 rpm you are going to notice something is going on under the hood. GM wants the Volt to be a very quiet luxurious type vehicle, so they can charge $40k for it.
They wont go for a bigger battery since it would cost more money, they want to keep that optimal-for-80%-of-the-public 40 mile range.. it may turn out that range anxiety is exagerated and thus they reduce the range to 20 miles, or perhaps they will increase it.. it all depends on what buyers demand.
Changing the size of the motor and generator is no big deal, they will do this as needed.
November 12th, 2009 at 12:19 pm
Define “Electrical coupling”.
November 12th, 2009 at 12:23 pm
Ugh,
A) It’s limited to 100mph BECAUSE of the genset output, simply so there’s no “it can’t go as fast when the engines running”
B) It would be IMPOSSIBLE to accelerate full throttle for one minute 37. Picture it. i’m stationary, i put the pedal to the floor. after 9 seconds i’m doing 60. after ~25 seconds i’m doing 80. After ~50 seconds i’m doing 100. at this point, i stop drawing 112kw, and will only draw 53kw. Even if i decide to stop and do another full power start then while braking i get both the full regen and 53kw from the genset to replenish the buffer. i cannot empty it.
C) I can only empty the buffer by nailing it -CONSTANTLY- going uphill. can you think of a hill where you don’t have to ever slow down for a bend, a narrow section, a crossing, a bridge, a speed bump, other traffic etc? I can’t. i also can’t think of a single hill i’d be happy to climb at 100mph!
November 12th, 2009 at 12:29 pm
It could mean that the generator motor generates power and then sends it to the traction motor, that is “electrical coupling”.
It could also be “information coupling”, the computer is predicting how much power the car/traction motor needs and adjusts the genset accordingly, even before the demand presents itself.
It could also be “magnetic coupling”, where the exterior magnetic field is recovered to enhance the performance of the motors.. I never have heard of this done on AC motors but perhaps.. note that I’m not talking about a magnetic clutch.
“Mechanical coupling” would require one or two friction clutches and perhaps even a simple multi-gear transmission.. probably not used in the Volt since it would cease to be a “serial electric”.
November 12th, 2009 at 12:30 pm
Thanks! I’m a data analyst by trade, so that means a lot to me.
November 12th, 2009 at 12:34 pm
You hit the nail on the head, though I would also add the following:
Since virtually no “mountain passes” are a straight road straight up the side of the mountain, there will be sections of road that aren’t as taxing as others. During the steep portions, the buffer will be used, and during the flatter portions the genset will replenish the buffer. During downhill sections, the genset and the regen braking will help top up the buffer. Even when traveling over the Rockies or the Appalachians, there will be multiple opportunities to both draw and charge the buffer zone of the battery pack.
In addition, not all grades, even on a mountain pass, will be steep enough to require significant use of the buffer, if at all.
The chances of needing to drive flat out up a significantly steep grade long enough to drain the buffer completely is slim to none. The average Volt driver will never encounter this scenario, and only the rarest of individuals may from time to time. Engineering a system for that rare an event is not cost effective or efficient. There has to be a line somewhere between reasonable and comprehensive performance, and just plain ridiculous.
I expect the engineers at GM are very aware of the real world requirements for the Volt in CS mode, and have designed a system that will work seamlessly in all but the most ridiculously extreme circumstances.
November 12th, 2009 at 12:34 pm
Very similar to the situation in my 93 Ford Escort when climbing big hills (The car had 88 HP). The Volt will be far better than this.
I would hope that GM could dip into the buffer to make up for short bursts of power need and that a prolonged need for max horsepower simply would be a very rare occasion.
November 12th, 2009 at 12:36 pm
I can see it happening on a race track.. and you know that is the first thing many testers (with a hatchet to bury) will do. The second thing they will test is CS Mode mpg at a brisk pace of 75mph. Witness what Top Gear did to the Prius on a race track. This will be a serious marketing challenge to the Volt.
November 12th, 2009 at 12:41 pm
@Flaninacupboard 50
C: My wife drives like a battouttahell. On a long drive to Southern CA on I-5 after passing dozens of slower cars and trucks on the freeway, 200miles, the Volt will be at it’s low point of SOC. Now we reach Tejon Pass up the “Grapevine”, at least 5-7 miles up hill and now we pass more slower cars and trucks going up hill and probably “Flooring it”.
This scenario will play out Waaaaaayyyyy more often than you belive.
B: I think my scenario above covers this.
November 12th, 2009 at 12:47 pm
They may find out that 30% buffer is too much and perhaps even lower it to 25%.. and they may even make it self-adjust this to your driving style, if you are a particularly agressive driver the computer may even increase it to 35%, if you are gentle lower it to 25% and give you a bit more electric range.
BTW, Alex did not say 30% was the discharged point.
November 12th, 2009 at 12:47 pm
Hey, what happened to the edit features?
November 12th, 2009 at 12:51 pm
In addition to post 56….
On the I-5 200 mile stretch, nobody drives below 75mph and yes most drive 80-85mph on that stretch. If you don’t belive me, try driving that strecth yourself.
Noel Park, do you agree?
November 12th, 2009 at 12:56 pm
Can’t believe you didn’t ask the MPG in charge mode?!?!
Enquiring minds want to know.
November 12th, 2009 at 1:01 pm
To #28. All EV voltages must be regulated. The challenge is to ensure the 30% SOC provides sufficient margin given all the load and temp variables-in order to maintain a minimum ‘flat’ voltage. The latter a function of the discharge load versus time. At what point the ER charges and to what point while in drive mode is, on the other hand, a marketing decision. Here I would want GM to make a conscious decision and allow the driver to override the upper charge point-the driver of course knowing such override will dramatically impacts mpg. One (of many) reason being for use in really hilly regions. Another being the driver wants range over mpg. Here’s a basic overview of battery operation. http://www.mpoweruk.com/performance.htm
November 12th, 2009 at 1:03 pm
Precisely!
This parallels those who travel from the flatlands up to the Ski lodge and no one drives the speed limit. The general traffic speed even uphill is at least 70mph. Any slower and you are the “Obstruction of traffic”.
November 12th, 2009 at 1:29 pm
“and comments are that they cant tell when the engine is coming on or off”
I wonder if they are using a type of echo cancellation or creating a white noise so to control what the driver hears or experiences? That is if you turn on a digital sound when the engine is not running and lower it when the engine comes on?
Other than that with thicker type glass, better padding it would be hard to hear outside noises like an ambulance..
November 12th, 2009 at 1:41 pm
It’s human nature to criticize that which we have not exerienced, when our past experiences have been negative.
November 12th, 2009 at 1:52 pm
You would not have understood her answer.. Alex can be a little obtuse at times.
November 12th, 2009 at 1:52 pm
The car will probably ‘learn’ your preferences by your driving style and route. I would expect that the car would heat/cool prior to your expected departure time in the morning as well while on grid power.
There is also some speculation that the GPS would be used to anticipate grade and other changes along the expected route of travel. Maybe tied into the route computer based on your destination input. We input our destination already to find the best route. The car just doesn’t do anything else with the information right now.
Some cars already learn certain preferences such as the top speed cut-off point. Certain other preferences can be set depending on the driver (such as seat position). This is already done manually in most cars in the 40-50k range. My gas gauge, for example, knows to warn me earlier that I am low if I am going 70 vs 35mph.
With tight integration to GPS and OnStar, the possibilities are mind blowing. The engineers have described Volt as a ‘rolling computer’ on more than one occasion. I expect that there will be some nice little surprises in there for all us techies.
“Dave, why have we changed course? On Thursday mornings, we usually go to work first.” lol. Give me Majel instead of HAL though.
November 12th, 2009 at 1:52 pm
I’m quite certain GM has sized the motor with plenty of capacity for the Volt needs and more – to get 150 K miles of service with no problems. More horsepower would then only require upping the controller circuts and ensuring proper motor cooling.
November 12th, 2009 at 1:55 pm
My initial estimates suggests that costs for the ICE per Kw*Hr are higher then from the grid, but the difference is not as great as you would think. Here are my estimates.
1. ICE efficency = 250 gm/Kw*hr or .410 lbm/hp*hr
2. Generator Efficency = 0.9 or 90%
For $2.50 gas price = $0.255 /kw*hr
For $3.00 = $0.306 /kw*hr
For $4.00 = $0.408 /kw*hr
For $5.00 = $0.510 /kw*hr
Just to doublecheck this estimate. If the grid price is $0.10 / kw*hr, then for 40 miles, it would cost $1.00, (10 kw*hrs). This would be equivalent to a car getting 100 mpg @ $2.50/ gallon (2.5*40 miles). This means that the ICE cost is 2.5 times (for $2.5 gas price) the grid cost, confirming my estimate.
One last consideration, if 10 Kw*hrs is required for 40 miles, then the fuel economy under the ICE-only mode should be 39.2 mpg.
2721 gms/galofgas / 250 gms/kW*hr = 10.884 kw*hr/galofgas
0.9 (gen eff) * 10.884 kw*hr/galofgas= 9.7956 Kw*hr/galofgas (usable for propulsion)
MPG = 9.7956 kw*hr/galofgas * 40 miles / 10 kw*hr = 39.2 miles/gal
November 12th, 2009 at 2:10 pm
Think in terms of a transmission as you would mechanical coupling. The electric traction motor varies in speed depending on how much power is feed to it. With the ICE, its revolutions go up and down. The transmission keeps the engine operating in an acceptable range while allowing the vehicle to speed up or slow down. There is no transmission in the Volt but loads on the motors effect its operation, so there needs to be electrical circuitry to smooth out the feedback from the traction motor to the generator through to the generator set motor. As the magnetic field in the motor raises and falls, the current flowing through the motor has to be controlled. On acceleration the current sent to the motor increases the magnetic field but when the car decelerate that collapsing electrical field creates a current surge through the windings of the motor that must be channeled away; in this case to the battery pack There will be times when the current from the generator set is insufficient to drive the traction motor at the needed speed or during rapid acceleration. The electronic circuitry will draw additional current from the battery to augment what the generator set can provide. So think of the electronic circuitry as a transmission, balancing the demand for power from the power sources to the traction motor. I hope this helps with your understanding of what Hermant was saying.
Happy trails to you ’til we meet again.
November 12th, 2009 at 2:12 pm
“Little to be gained” except fantastic gas mileage.
Whenever the ICE is on, it is burning gasoline. The Prius turns the gas engine off whenever it can, to avoid burning gasoline. The Prius has sold more than a million units so far…
I think the Volt engineers have noticed this.
If the Charge Sustaining Mode battery buffer is 10% (30% down to 20%), there will be plenty of driving situations in which the ICE can be shut off (imperceptibly is best), drive on just battery power for awhile, then turn on the ICE (imperceptibly) to fill up the battery buffer again or power the traction electric motor, or both. The ICE should turn on only when needed.
The driver doesn’t have to worry about this – the software will calculate how to give great MPG, 150 hp when needed, and you still get to commute on pure electric power.
I would gladly trade a few more particulate emissions for 5 or 10 more MPG in CS mode. And so should the Volt engineering team – how many people even know about their particulate emissions ? But CS mode MPG will be the first thing mentioned in “Car and Driver” tests next Summer.
November 12th, 2009 at 2:16 pm
I sure hope not. This would mean a long series of cascading losses.
Here’s an example…
Regular ICE car:
Ice converts petrol to mechanical energy to drive the car.
Parallel Hybrid:
Ice converts petrol energy to mechanical energy to drive the car.
Simultaneously, DC Electrical energy from batt pack is converted to mechanical energy/torque to help drive the car.
At some point the Ice converts mechanical energy to AC electrical energy…
Then electrical AC energy to DC into it’s small batt pack.
Series Hybrid:
Ice converts petrol to mechanical energy…
Mechanical energy is converted to electrical energy (Generator)…
Electrical energy is converted to DC…
DC Electrical energy is reconverted back to 3Phase electrical energy (AC motor controller)…
3Phase electrical energy is converted to mechanical energy/torque to drive the car.
So, as I undertand this “Electrical Coupling”, it’s like this….
Ice converts petrol to mechanical energy…
Mechanical energy is converted to 3Phase AC electrical energy (Generator)…
The 3Phase AC electrical energy is then converted to mechanical energy (by drive motor) and drives the car.
If this is the case, then power from the AC motor controller must be disengaged because you can not use more than one source of AC power. Can anyone confirm this? Can you plug into one 3Phase AC source and another 3Phase AC source (Parallel) for more power?
November 12th, 2009 at 2:22 pm
Since they’re still adjusting and refining, they can’t quote the CS mode MPG yet.
I doubt that they will ever quote the raw CS MPG since nobody will ever drive in pure CS mode. Even if you don’t ever plug in, you will regen some power and still have battery power for some portion of operation.
imho, buying a Volt and not plugging it in is like buying a ‘Vette and never going over 55mph.
It is in GM’s best interest to keep saying things like “combined MPG will be greater than 100″ rather than quoting some number for CS mode that is irrelevant to almost all drivers. (Yeah, yeah, there are a couple of fanatics here that fall well outside that bell curve!)
November 12th, 2009 at 2:24 pm
I’d bet that she will learn fast when on that trip she ends up stranded somewhere and has to call for a tow. Perhaps, then she will learn to drive at a reasonable speed. For your sake, I hope that you aren’t in the car when it happens. Either that or never let her drive your Volt!
Happy trails to you ’til we meet again.
November 12th, 2009 at 2:28 pm
Lyle moved it to the top of the comment from the bottom.
Happy trails to you ’til we meet again.
November 12th, 2009 at 2:31 pm
What about DC conversions? The battery is in the middle of all of this. It has already been stated that the battery supplies more power if needed for acceleration in CS mode.
November 12th, 2009 at 2:33 pm
That stretch of I-5 is also flat and boring as heck. Even cruising at 85 mph doesn’t require peak HP from the motor. I expect there will be plenty of extra juice available to make it up the Grapevine at least as well as any standard ICE car.
November 12th, 2009 at 2:36 pm
This is all encouraging news.
I’m hoping GM will provide visitors to the January 2010 North American International Auto Show in Detroit the ability to take a test ride in a Volt. During the 2009 Detroit show they provided visitors with short test rides in their hydrogen fuel cell SUVs on a special roadway they installed in the basement of Detroit’s Cobo Hall.
November 12th, 2009 at 2:37 pm
I couldn’t care less. I used to drive a 36 hp Volkswagen, LOL. And I tow a big trailer quite a bit. When we go to Portland, it’s about a 2000 mile round trip. With our big trailer there are probably about 20 miles of that where the driving experience is not “seamless”. Probably less than that with a Volt. And in city driving, it’s obviously not a problem.
So, if I have to experience somewhat less power less than 1% of the time, which I doubt will happen anyway, in order to gain all of the advantages of the Volt, once again, I couldn’t care less.
LJGTVWOTR!!
November 12th, 2009 at 2:41 pm
On Power Fade Issues
We already have a model for this
the Toyota Prius.
The 2010 Toyota Prius uses a 100 hp Engine and a 80 hp Motor. If the Electric motors 80 hp and 153 ft-lbs are missing because of battery depletion, I think this would be quite noticable. Althought the Prius gas engine outputs 100 hp and 105 ft-lbs, the Prius curb wieght is above 3,000 lbs and the Aktinsons style engine will suffer in High Altitudes just like any other NA engine. Pushing around a this car in the mountains with no battery -should- be extremely noticable.
The -Entire- size of the 2010 Prius battery is 1.3 kWh. Just like the Volt, Prius will never have more than 80% SOC. I see on the internet, that the Prius seems to cutout out battery usage at 40% SOC. Thats a difference of .4 of 1.3 kWh or 0.5 kWh availible, -best case senario- for the Prius. If Volt uses 10% of SOC as a buffer… that 1.6 kWh or 3 times the entire usuable range of the Prius.
Now, the Prius has a lower power motor at ~60kw, and I see that a max it gets 100 kW from the motor and the engine. If we assume a power draw of 27 kW (this btw is the max the batteries can provide, regardless of the electric motors actual specs), the Prius can assist for only 1.1 minutes at maximum throttle. (See above for Rough Calculation of Volt at 1.3 minutes)
Q: Has any Prius owner noticed a “Power Fade” Issue? I gave never heard of this issue.
Therefore, I think its a reasonable assumption that the Volt will not suffer power fade issues.
BTW, the Volt should be able to put approx 9 kWh of electricity “into” the battery (If the ICE was use to feed power directly to the battery) per gallon of gasoline burned. At 3 dollar gas, that 0.33 cents per kWh.
November 12th, 2009 at 2:47 pm
#32
If the Volt doesn’t meet their needs, maybe they should get another car. A nice Malibu with a V6 comes to mind. The Volt is pretty obviously not for everyone, and there aren’t going to be enough to go around for a few years anyway.
November 12th, 2009 at 2:54 pm
These numbers are saying that the cost per kwh generated is two to five times the cost of grid power, depending on the price of gasoline at the time of calculation. Not so bad on the surface.
If I can generate power at ~ 25 cents, then, it is cheaper than peak grid costs. I should be connecting the car up to the grid during peak and make some money!
None of this takes into account the true cost-of-operation for a generation facility. The initial cost and maintenance would increase the cost per kwh generated quite substantially. Gasoline is only a portion of the entire operating cost.
November 12th, 2009 at 2:55 pm
#44
No problem! When we get our Flowmaster muffler with the 4″ chrome tip, everybody will know that the Volt’s in town. The wonderful “aftermarket” is waiting to help you, LOL.
November 12th, 2009 at 3:01 pm
Having driven a variety of hills and mountains in my Accord Hybrid I’m constantly surprised at how much time it spends with the batteries too FULL instead of too EMPTY. And yes, occasionally while going up the hills, too.
Of course, it’s a much, MUCH smaller system than what the Volt uses but the battery management is kind of similar. It tries not to drain the battery below something like 40% and tries not to charge it above something like 80%. In extreme cases of demand for power or charging it will go all the way to 0 or 100%. Also important is that the rate at which is can charge the battery (from the engine, not from regen) is considerably smaller than the rate at which it can deplete it.
(At least as far as I can tell from the little battery indicator and using it
I’ve driven the car many times through the Tejon pass (~4000ft) on the way to LA, the one on I-5 at the Oregon border for which I can’t remember the name (about the same height. ish.) and the biger ones over in the Sierra Nevadas, Donner and Tioga (~7000 ft & ~10,000 ft, respectively) plus frequently driving up highway 9 to skyline where all the Teslas go.
Also long but not so high ones like the Pacheco pass.
What I consistently see is that in the steepest sections (especially if there’s a passing lane, heh heh
the little traction motor is full on and can deplete the battery most of the way but usually not all the way (although I have done it when passing, er aggressively), but overall on the way up mountains there are always not-so-steep (and even flat or downhill) sections where the engine or regeneration is recharging the batteries. Inevitably, when I come down the mountain again the battery fills up in the first few miles and I curse how much it had charged the battery on the way up.
I guess my point is that I’ve been surprised how many big uphill sections are not actually just uphill sections. When you actually see what your charge system is doing there’s surprisingly more areas the car can charge in than you would have guessed before seeing it happen. I’m even surprised at how often I’m regenerating while still going uphill because of having to slow down for trucks and whatnot.
The general traffic gets very slow indeed in the sierra nevada passes as the normally aspirated engines run out of air at high altitudes. I imagine the Volt could fair well better than the average car in the highest passes but it’s tough to guess exactly at this point what will happen.
November 12th, 2009 at 3:06 pm
Close Ron Hall. What you are forgetting though is the efficiencies in getting the electrical power into the Battery and Out of It Again.
If as we presume 10 kWh -from the wall- is required to get 40 miles, then Fuel Economy under ICE-only mode should be more like 39.2 mpg X 1/(.85 see ANL estimate of .84% efficiency for PHEV conversion Hymotion Prius) or 46 mpg
November 12th, 2009 at 3:09 pm
#59
To quote the famous A. J. Foyt: “Well this is quite true.”
Again, if the Volt slows down going over the Grapevine a couple of times a year, I can live with it. After some of the cars I have driven in my life, I’m sure it will feel like a Corvette, LOL.
LVGT!@#$VWOTR!!!
November 12th, 2009 at 3:11 pm
Quite true, but no sense asking a question when you know you aren’t going to get an answer, LOL. All in good time, I guess.
November 12th, 2009 at 3:12 pm
(click to show comment)
November 12th, 2009 at 3:16 pm
I thought the answer was “between 40-50MPG”?
lol
November 12th, 2009 at 3:22 pm
We just dont know this level of detail.. I am beginning to suspect that the Volt will skip the DC conversion step.
November 12th, 2009 at 3:27 pm
With regard to smoothly starting the engine, I would guess that the Volt will inherit the damper and damper bypass clutch from the 2MT70 Two-mode Hybrid whose tranny case is so similar.
If you read the paper SAE 2009-01-0508 “General Motors Front Wheel Drive Two-Mode Hybrid Transmission” (available for $15 download at http://www.sae.org ) it explains in the section “Damper-Bypass Clutch” that engaging this clutch during engine startup minimizes system resonance.
This is a plausible explanation of how the Volt engine startup might be barely noticable.
November 12th, 2009 at 3:28 pm
You’re AC assumption I believe is incorrect. Currently I have 200amp AC into my house. On the roof of my house I have solar panels which produce DC. The DC is routed through my SunnyBoy Grid-Tie Inverter which converts the DC back to AC. The AC lines out of the inverter are tied directly into the AC panel. The house will use solar produced AC over the commercial power but once I use more what the solar panels can provide the power comes from the commercial lines along with what my panels produce. There is no split or shut off of one over the other. The inverter matches the 60hz frequency of the commercial AC and both can provide power to the house at the same time. The Volt may use something similiar, matching phase for the AC motors so power can come from battery, gen or both. Someone please correct me if this doesn’t sound correct.
November 12th, 2009 at 3:30 pm
Tru dat!
We’ll just have to wait and see.
November 12th, 2009 at 3:34 pm
Someone mentioned catalytic converter in a prior post. The catalytic converter must be hot to function correctly. Since the Volt does have an ICE, I’m sure it’ll still need to pass a smog test. Chevy must be putting in a forced run switch on the ICE so the smog check can be completed.
Of course there’s always the chance that since the ICE doesn’t run much, the states will wave the smog check and the fee they collect. Oh by the way I just saw a flock of pigs fly by my 3rd story office window. :^o
November 12th, 2009 at 3:37 pm
#84 Steel
Good catch!
I’ll take the higher estimate. We’ll see when they publish the actual numbers, but these estimates suggests that it will be high on the EPA MPG list when the ICE is running.
The Volt is a winner all around except for initial cost, which only time and mass production will solve.
November 12th, 2009 at 3:37 pm
You’re wrong there bro. The genset will “operate in several rpm ranges”. This means the AC Motor controller will also need to adjust the freq according to Genset RPM. If they, 3Phase AC, are 45, 90 or 180 deg out of phase, you have a carbque.
November 12th, 2009 at 3:53 pm
That’s perfectly fine because the SunnyBoy is a constant 60Hz with a very very narrow freq deviation. For a genset it will deviate from a few hudred Hz to maybe a thousand or more.
The method used for your Solar package is a little different from here in CA, or at least from what I was told by the solar guys. What they do here is “Net Metering”. The Solar package will do the DC to AC conversion and pump juice to the grid. The house will still be connected to the grid and use grid juice. Your Solar KW production is then deducted from your useage. At the end of the year if you used more than you produced, you pay $$$. If you produced more than you used, it’s a wash and you don’t get jack squat back.
You might have a much better plan.
November 12th, 2009 at 4:03 pm
Can anyone calculate how many vertical feet 1.6kwh could hoist let’s say a 4,000 pound car? I’m thinking that would represent an absolute rock-bottom terminus a quo for the Volt’s climbing ability, completely disregarding the ICE’s contribution during the climb.
November 12th, 2009 at 4:08 pm
Need to know the Time Factor
November 12th, 2009 at 4:21 pm
That’s the same arrangement. The inverter is tied into the breaker box just like the grid is tied into the breaker box. It’s not like there’s two lines to the power company, one for outbound power and one for inbound power. If you’re using less than you’re making, the meter spins backwards as power flows out. If you’re using more than you’re making, the meter spins forward as power flows in.
November 12th, 2009 at 4:51 pm
I’m looking forward to the FIRST thorough 3rd party road test of the Volt. GM should let the car magazine or whoever (Lyle maybe?) have the Volt for a couple of weeks or so. Test the heck out of it in all sorts of driving scenarios.
I bet we won’t have to wait too much longer. Maybe March or April of next year? Time flies you know. It seems like just yesterday that the Volt was just a “pie in the sky” concept project. It’s getting very real now. Let’s hope when the curtain finally comes up for the Chevy Volt World Premiere in November 2010, it’s going to be a smash hit.
November 12th, 2009 at 4:59 pm
1.6kwh is enough to lift a 4000lb car 326 meters straight up, assuming no losses.
November 12th, 2009 at 5:02 pm
I gotta get me one of these!
November 12th, 2009 at 5:11 pm
I don’t think so. I’m talking about kilowatt-hours, so it doesn’t matter if you hoist it fast or slow (discounting wind resistance). A 1-kilowatt motor hoisting for an hour would lift it just as high as a 60-kilowatt motor hoisting for a minute. (Um, am I right about this? I don’t do this kind of stuff for a living…)
According to The Internet, 1 horsepower will lift 550 pounds one foot in a second. So a horsepower-second will lift 550 pounds 1 foot, or 1 pound 550 feet. So a horsepower-hour (3600 horsepower-seconds in a horsepower-hour) would lift a 3600-pound car 550 feet. 1.6 kilowatts is a bit over 2 horsepower, so 1.6 kilowatt-hours is roughly 2 horsepower-hours, which would lift a 3600-pound car (I’ll use that to keep the arithmetic simpler) 1100 feet.
So the 1.6kwh estimated by Flaninacupboard would handle 1100 feet of vertical climb, without any contribution at all from the ICE other than overcoming drag.
Now if the ICE outputs 53kw, and assuming it takes 23kw to push air out of the way at the speed I’ll be climbing Mount Washington, that leaves a nice round 30kw to contribute to altitude gain. 30kw is roughly 40 horsepower. 40 horsepower-hours would hoist a 3600-lb car 40 * 550 feet, or 22,000 feet of vertical climb in one hour. Mount Washington Auto Road is about 4,000 feet of vertical climb, so it would take me (calculating only the vertical component) 1/(22,000 / 4,000) = 1/ 5.5 hours, or 11 minutes to overcome the gravity component of the climb using 30kw from the ICE.
Now since the battery will contribute 1,100 vertical feet to the effort, it will take me… OK, now I’m confused — I wonder if I’ve done something fundamentally wrong… nope, I think I’m right… 1/(22000/2900) = 1/7.6 hours, or 8 minutes to climb Mount Washington in my Volt, considering only the vertical component.
OK, smart people. Is there any chance I got all that right? Tell me where I went wrong. Do not base any investments on my math!
November 12th, 2009 at 5:14 pm
PoopyPantaloons=TROLL! Wow we haven’t seen one of those in a while…… Like since the IV’ers rolled thru town!!!! They must be bored! HAHAHAHAHAHAHA!
Volt rules!
November 12th, 2009 at 5:20 pm
My educated guess is (Any Frequency) AC made by ICE converted to DC to the battery then AC generated electronicly (with variable voltage and frequency) to power traction motor. Research Tesla or AC Propulsions websites. That’s the way I would do it if it was me, and you have no frequency matching issues….
November 12th, 2009 at 5:30 pm
I would say your right. Nice little example to make it easy to understand!
Happy trails to you ’til we meet again.
November 12th, 2009 at 5:32 pm
YUP!
You Rule Ricky Bobby!!!
November 12th, 2009 at 5:47 pm
Let me ruin your day, in my neck of the woods, (effective four weeks ago), we can sell back to the grid at 80 cents per.
/don’t do the math
November 12th, 2009 at 5:48 pm
November 12th, 2009 at 5:50 pm
#19
Well I dunno pal. if you look at the efforts of Mr. Pantaloons today, I would say that they might be creeping back.
November 12th, 2009 at 5:52 pm
#87
Alas, it looks like CorvetteGuy was a little bit premature at #19. -1
November 12th, 2009 at 5:54 pm
#88
Works for me. Keep the faith!
November 12th, 2009 at 6:05 pm
#108
Well somebody in your neck of the woods is way ahead of the curve. I bet if we figured out the cost of fuel, and creating new generating and distribution infrastructure here, that would be cheaper than the marginal cost of creating new capacity. I bet if that was the case in SoCal, the roofs would bloom with solar panels.
November 12th, 2009 at 6:07 pm
Punk….
lol.
That’s pretty awesome. If they did that in the US, it would make going Solar more desireale or feasable.
November 12th, 2009 at 6:15 pm
I think he/she/it is an undecided troll…..lol
he/she/it sounds like he/she/it is looking for validation????
Or….maybe not.
November 12th, 2009 at 6:26 pm
… and would this mpg reflect any contribution from regeneration (or is that included in the efficiency factor), low-rolling resistance tires or aerodynamics?
I’m still holding out for 50+ on Charge-Sustain mpg.
Thanks guys for doing all these fascinating mathematical musings (so that I don’t have to
).
November 12th, 2009 at 6:54 pm
kdawg,
Thanks. That’s good info. +1
November 12th, 2009 at 6:59 pm
I would be interested in seeing how it does starting at battery of 30% in C/S mode from Durango, Colorado going to Silverton Colorado on US550. I can take it easily at the speed limit (55 mph for quite a while, drops lower once you get to the mountains) in a Prius. Altitude gain of between 3000 and 4000 ft.
November 12th, 2009 at 7:07 pm
I disagree with Dave P. Sorry. The Accord hybrid has a V6 and a dinky little battery. Not at all what the Volt experience will be like. The Accord has plenty of power WITHOUT any electric motor assist at all.
November 12th, 2009 at 7:09 pm
Take the narrow gage railroad. Life’s not always about driving!
November 12th, 2009 at 7:09 pm
MuddyRoverRob,
That’s good info. Thanks. +1
I hadn’t read about ‘Mountain Mode’ previously.
I agree that this issue is being blown out of proportion. But I live in Michigan where hills won’t be an issue. Maybe it is a legitimate issue for some. I’d be interested in finding out how much of an issue it really is and how many people it would impact.
I also agree with you that having the Volt use it’s nav system to increase the buffer in advance would be ideal. But the charging rate of the battery via the ICE/genny is likely pretty slow. The nav system would have to consider a very large radius to increase the buffer in time.
November 12th, 2009 at 7:13 pm
That’s true in any vehicle. My 2.5L Ford Ranger can climb the mountains west of Denver with a load faster than the tractor-trailers, but slower than the sports cars. Also, my car gets noisy when it’s climbing a hill. The same is true for every other car I’ve driven, even the mildly-sporty ones. I don’t see a problem here.
November 12th, 2009 at 7:13 pm
I’ve been driving a Prius for more than 5 years. Every once in awhile you get a depleted battery, and the ICE strains (you can hear it) and the car is a bit sluggish. The only really bad time in 5 years was when I was driving up the Rocky Mountains for hours, at one point the battery was depleted and I had to limp up in the right lane at about 45, 50 mph. But it was only about 30 minutes of inconvenience, balanced by averaging 53 mpg for a cross country drive – it was worth it for me.
In the Prius, they give you a battery meter so you can know when the car might get sluggish (if there is only one or zero bars in the battery, the ICE strains to power the car, plus charge the battery when it can). The 8 bars in the battery meter are mapped to the 0.52 kWh battery buffer in the entire NiMH battery (that is, 8 bars is not 100% SoC, 0 bars is not 0% SoC).
I think the Volt should have something similar – don’t try to hide the details entirely (at least from drivers that have had the car awhile and know how it works) – there will come a time when the power fades, it is useful to know why; you can slow down a minute, or turn off the A/C a minute, until the battery buffer fills up again.
Engineering is always a compromise – if you want CS mode with good MPG, accept the occasional ‘power fade’. If you need 100% power available at every second of every drive – get a different car. There will always be a rare situation that causes ‘power fade’ no matter how the software is designed for the Volt.
November 12th, 2009 at 7:16 pm
If all 53 kW of the generator output is available for battery charging you can add the full 8 kWh to the battery in 8/53rds of an hour (i.e. just over 9 minutes). I realize you don’t want to arrive home fully charged, but you could do it this fast if you wanted to.
November 12th, 2009 at 7:21 pm
Loboc and CJS,
You can certainly have the firmware and software to merge AC. It happens everywhere additional power is returned to the grid. It is a very easy process.
Did you know that the sine wave phases must be matched precisely into the grid for your solar power system to feed into it and synchronize to those 60 hertz? They even track with the precision of a millionth of a second the matching of that sine wave.
In fact, there is so much time left over within the sine wave on each phase (of 120volt household), that many TV’s send back data (there goes our privacy) to somewhere just like refrigerators do to call for repairs so food does not spoil.
There is so much “unused time” within a 120 volt sine wave being at “off” within that one sixtieth of a second, that the TV or Refrigerator or Smart Meter, can send all manner of data, refrigerator faults out to call for repair so food does not spoil, to the Toshiba Wide Screen TV (makes a “click” when it comes on and, mine won’t run on solar powered battery with 150 watt pure sine inverter, because that TV I got from Fry’s which will not accept power from/run on a pure sine inverter (150 watts), because it is trying to locate the actual grid. (I wonder if there is visual data of my living room also being sent. Would not surprise me at all in this day and age of gross privacy invasion of the home, which I completely object to 100%)
So the Volt tech would never have a problem from merging wattage from the inverter, generator, and also, send power back to the battery from regen and generator.
November 12th, 2009 at 7:40 pm
PS, Fry’s techs verified that data is being sent by that TV (discounted to buy privacy-invasion rights as far as I am concerned), and, he also verified that the TV was searching for the grid. He said the warranty on it would be void if I used a pure sine inverter with the 104 watt 32 inch Toshiba.
When I did use the 150 watt Aims pure sine inverter, I also had a true RMS digital voltmeter in one of the inverters outlets. The TV first came on, then after about 10 seconds, the inverter made an unusual buzz, the voltmeter went from 124 volts to 118 volts , then from 122 volts to 116 volts, then from 120 volts to 112 volts, then from 118 volts to 110 volts, then the TV shut itself off.
I had previously tried to buy a 300 watt pure sine wave inverter from Fry’s but after 2 weeks they kept saying it wasn’t in yet. So, if you borrow a 12 volt dc (powered by a car battery) pure sine wave inverter and try to power your TV and after 30 or so seconds the TV shuts off, then you might have a data-sending TV, which, in my book is a complete violation of my rights as a home owner.
Anyone know a good lawyer that is technical who is in Austin, TX?
November 12th, 2009 at 7:42 pm
From Google Maps, it looks like the steepest part of the climb is from 8,800 feet to 10,400 feet, or 1,600 feet over 5 miles for 320 feet per mile.
Never having driven out West, I tried to think of something from my experience that would compare. Burkhalter Gap Road between Trenton Georgia and Lookout Mountain climbs from 800 to 1,800 feet in 2.2 miles, or 454 feet per mile in one straight continuous climb. Back in the day, I did that many times in a ‘74 Rabbit with no difficulty at all.
So assuming we want to maintain a mile-a-minute, and let’s say 500 feet per mile in a straight relentless climb, who wants to figure out how many kilowatts are needed to hoist a Volt straight up at 500 feet per minute, ignoring all other factors?
My poor head hurts from too much math. Good night, all.
November 12th, 2009 at 7:48 pm
The Volt’s total system power drops once it gets to 30% SOC. Not my opinion; Alex states this in the original article. She mentions that using some buffer from the battery, she is able to manage to have the power when you need it. With the right terrain, she can restore these losses so power is available the next time you call for it. When climbing a long hill, you don’t get this chance to restore the buffer.
As a long time RV owner (over 30 years of travelling) who has crossed this country many, many times, I know full well that there aren’t too many long hills in cities. But if you have ever crossed this country, you know that there are many, many places where hill climbs of 5% grade and more than 4 or 5 miles of length are encountered.
When I’m out in the RV, I carry a set of publications known as the Mountain Directory (2 volumes; East and West). These books list over 700 mountain passes (many on major interstates) which exceed a 5% grade and extend at least a handful of miles. For example, Northern California has 36 listed. Southern California has 41 listed. West Virginia has 35 listed. Between Virginia and Kentucky there are 45 listings.
In West Virginia alone I find Interstate 64 east of Beckley, 5 miles of 7% grade; I-77 between Beckley and Princeton, 5 miles of 5% grade; US-33 between Harrisonburg, VA and Judy Gap, WV, 4 1/2 miles of 9% grade.
Maryland has one of my favorites. I-68 west of Cumberland, 13 miles of 6% grade. That one’s a doozy! I could site dozens of additional personal examples. Most of them on the interstate highway system. If you get off the interstate, the hills get much steeper.
Hey, I’m not trying to beat anybody up over this. I want a Volt as much as the next guy. What I’m trying to point out is that the Volt isn’t like other average four door sedans. It is relatively underpowered compared to most other cars of its weight and size class. Given its known design limits, it WILL have power problems in these mountain climb situations. There’s no point in denying that they will happen. Millions of folks drive these routes every year and if they drive a Volt, they will experience them.
The Volt HAS to be able to handle these hill climbs… and it will. But certainly by the top of these inclines, it will be moving just a little bit slower than those average four door sedans. That’s part and parcel of a 230 mpg car! It’s not a bad thing, it’s just not the same as other cars. I’m not going to kid myself and pretend that it won’t happen. I don’t think you should either. And GM shouldn’t try to kid us. Hey, GM, it’s OK to tell us the whole truth. We can handle it. Hell, we want to handle it. We all want a Chevy Volt!
November 12th, 2009 at 8:03 pm
Is it 44.9, assuming a 4,000 pound Volt?
November 12th, 2009 at 8:26 pm
Lyle – great post. Very exciting review by Alex. They NEED to let you get behind the wheel … very soon!
Side Note: took me 40 minutes to read all the posts from today – wow the prose where flowing today… nice job by all.
November 12th, 2009 at 9:31 pm
http://www.dailyfinance.com/2009/11/12/pumped-up-prices-4-per-gallon-gasoline-may-be-coming-in-2010/
Article above is related to thread from November 10 about taxing gas. If this projection is even close, no tax will be necessary. It looks like micro and macro economic conditions are lining up for higher gas prices and lower consumption.
November 12th, 2009 at 9:33 pm
Exactly…..
1% is rounded up from my guess of 0.01%.
November 12th, 2009 at 9:37 pm
Well, the Volt is NOT a serial EV, now that Alex has confessed to them using the 2MT70 transmission. The ICE has a mechanical coupling to the wheels in mode 2.
Sorry to disappoint, but we have been had. Volt is yet another GM concoction with its roots back to the 1990s where hybrid research was the rage.
Look for BYD or Nissan to come up with the first SEV in the US.
November 12th, 2009 at 9:48 pm
Yes, but I miss monkey hater.
November 12th, 2009 at 11:21 pm
I match your 5 years, raise it by 6 months, then call with a 2010.
Get behind the wheel of the new model and watch what happens. Of course, you may need aftermarket gauge to notice. It’s truly remarkable what the bigger engine and enhanced PSD offers in that situation.
November 12th, 2009 at 11:28 pm
I agree, I’ve driven the godforsaken 1-5 way too often. However maintaining a constant 80mph speed doesn’t require drawing from the battery! 53kW is more than enough. Even the grapevine shouldn’t be enough to defeat the Volt although they should certainly test it there.
All this hand-wringing is a bit over the top. I doubt power in CS mode will pose an issue. Even if some idiots specifically try to screw up the Volt in CS mode they’ll have a very hard time doing so.
EDIT: this isn’t what I meant to quote… why does this keep happening to me?
November 13th, 2009 at 12:25 am
ccombs, if you left press your mouse, you can highlight the specific text you want to quote; then while it is highlighted, click (quote). Hope this works for you.
Happy trails to you ’til we meet again.
November 13th, 2009 at 12:49 am
Where did she confess to them using the2MT70 transmission in the Volt? Do you have a reference link?
November 13th, 2009 at 12:58 am
I hadn’t heard of the Mountain Directory – good to know, thanks.
I don’t think the “total system power drops once it gets to 30% SoC”. Alex said:
Now in charge sustaining we know that the engine power is slightly less than the peak vehicle power but we have controls ways to manage that and to utilize the engine in conjunction with the battery to get a little bit of extra power when we need it, and replenish it back when we don’t.
I think she means the ICE is only 71 hp, and the ‘peak vehicle power’ is 150 hp (the traction electric motor), but they have ways to combine electric power from the generator and the battery to offer 150 hp for short periods.
But you are right, in long hill situations, the 30% SoC goes down to 20%, or whatever lower limit GM chooses in order to extend battery life (a full discharge would kill the battery much faster). Then the total system power drops. There is a lowest limit under which they will refuse to discharge the battery, then you are driving on just the ICE power.
I think for a full battery buffer (30% SoC) in CS mode, you could calculate exactly how far you could go at speed x for an incline of y degrees. And yes, as you slow down, you could go farther. And if the incline is lower, you could go farther. But at some point, no matter what the battery buffer size is (30% to 25% ? 30% to 20%) you will deplete the battery energy available to you, for some speed and incline.
Then you have to slow down. Tragedy.
But the same applies to the Prius, and I don’t see that mentioned in ads or automotive articles.
Next summer, once the production version is finalized, the journalists will get their hands on the Volt, and they will probably try them on hills and mountains. I bet the performance will be pretty good, but there will be a point at which the battery buffer is exhausted, and the performance suffers.
But if CS mode is giving 50 mpg, and you can plug it in for cheap commutes and errands, I bet many if not most people won’t care about having to slow down 10 or 20 mph after driving 20 minutes up a steep incline (or whatever it works out to be).
I don’t think GM is trying to “kid us”, it just hasn’t been finalized yet. Next year, all will be revealed
November 13th, 2009 at 1:54 am
Mohsen has a very active imagination.. bless his soul.
November 13th, 2009 at 1:57 am
http://gm-volt.com/forum/showthread.php?t=1332
November 13th, 2009 at 2:58 am
What Todd says is correct. It really isn’t that complicated. An AC voltage source is just a sine wave. Three phase is just three signals offset by 120 degrees. If you want to combine two sources, just match the frequencies and phase of the two sources and the signals will just add up directly.
Edit AC, should use current as example instead of voltage:
For example you have one signal I1*sin and another I2*sin. I1sin + I2*sin = (I1+I2)*sin. I1 and I2 are the peak currents. And for the sin part as long as the two signals are in phase and have the same frequency (meaning drawing them on a graph, the location of peaks, zeros, and troughs should match up), then they will add up constructively.
http://en.wikipedia.org/wiki/Phase_(waves)
http://en.wikipedia.org/wiki/Three-phase
November 13th, 2009 at 9:16 am
Please consider that some people, (me for instance), are interested in the performance aspects of electric drive, and would want their engines running almost all the time keeping the battery fully charged for the next big power boost. People like us would want a performance mode for the electric drive software.
November 13th, 2009 at 9:19 am
I agree with you Noel, when I drove from Belgium to Spain with my children years ago, I towed a very heavy trailer with all of the stuff (for a three weeks holiday) for a family with 3 children, their and our bikes, the windsurf of my son, the cradle of the baby, and so on,…
When crossing the Ardennes, the Central mountains of France, and the Pyrenees it was not a seamless drive with a 55 hp VW station wagon, but we did it with fun more than a 12 dozen times in both directions.
“In order to gain all of the advantages of the Volt, once again, I couldn’t care less.LJGTVWOTR!! Right Noel,
JC NPNS
November 13th, 2009 at 9:52 am
I don’t see anywhere in this thread where it says that the Volt uses a standard shifting transmission (or even a CVT).
Even though the transaxel housing may be the same, the guts are missing. Meaning, the ICE DOES NOT drive the wheels.
November 13th, 2009 at 9:58 am
Why is “Charge Sustaining” an issue when the drive train is always propelled by a electric traction motor obtaining it’s power from batteries?
What is this notion that the power of the “Internal Combution” engine is not at its max power when it is driving the generator. I’m at loss at the issue. Of course the engine is not at it’s max power while performing it’s intended task. It has a load on it. This is not brain surgery, is it?
It appears to me that when the battery component gets dischared to a specific level the generator engine starts to drive the genrator so that the battery(s) can maintain a constant level of energy to drive the traction motors.
?*?*?*?####
November 13th, 2009 at 9:59 am
I can assure you that as stupid as it sounds, that little piece of the whole system is the most fun. Another couple of weeks, and we will have rewound ours past zero– i’m not sure if it will stop there, or roll around to all nines.
November 13th, 2009 at 10:06 am
Another Way Off Topic Item:
There will be an “Electric Avenue” display at the Detroit Auto Show.
http://www.business-journal.com/default.asp?sourceid=&smenu=1&twindow=&mad=&sdetail=15059&wpage=1&skeyword=&sidate=&ccat=&ccatm=&restate=&restatus=&reoption=&retype=&repmin=&repmax=&rebed=&rebath=&subname=&pform=&sc=1711&hn=business-journal&he=.com
November 13th, 2009 at 10:07 am
That’s awesome! We net-meter up to zero (effectively selling at the retail rate of about $.12/kWh), and from then on excess is sold at the wholesale rate of about $.03/kWh. Our payback time on the system cost will be about six years– but at EIGHTY MOTHERLOVING CENTS per kWh, the system would pay off in less than a year.
November 13th, 2009 at 10:53 am
Did nobody find huge errors in my math? I’m astonished; I’m really not good at it.
If my math and our assumptions hold up, then I think we’ve established that the Volt will eat Mount Washington for breakfast and take Lookout Mountain at full power without even noticing it’s there.
That’s good enough for my purposes.
November 13th, 2009 at 11:53 am
The electric traction motor can be driven directly from the generator, or from the batteries, or both. Converting the generator output to DC, charging the battery, then discharging that energy again to drive the traction motor incurs some conversion losses, so they try to match the power output of the ICE/generator as closely as possible to the second by second power demands of the traction motor. When the power demand exceeds the 71 hp of the genset, they get extra power from the battery. When that part of the battery they set aside to energy buffer the Charge Sustaining mode gets low, they run the ICE/generator at higher RPM’s than the traction motor needs, to recharge the battery.
The ICE has different power levels (different set RPM’s) which have been optimized for maximum efficiency (converting gasoline to electricity). If they just ran the ICE always at its ‘max power’, to top off the battery to 30% SoC, and let just the battery drive the traction motor, they would always incur maximum conversion losses, and the ICE would be turning off and on constantly. They are trying to minimize the noise and vibration of the ICE, but I think that even so, it would be annoying for the ICE to turn off and on all the time while driving.
GM is tweaking the Charge Sustaining mode to balance battery life, performance over a wide variety of driving situations, MPG, and driving “feel”. It’s not a simple matter of maintaining battery charge at 30%.
November 13th, 2009 at 12:43 pm
Dear Jackson,
I don’t care what the Volt does for local trips when it gets down to 30%. It doesn’t seem very significant to me. The point I’ve been trying to make for several years is ; on a long trip(238 miles to my mother’s house)
Hilly terrain along I-81 in Virginia
I want the genset to charge the batts back to 80% and then shut off. It doesn’t need to hunt around at three different rpms to try and match load and then leave me at the mercy of some stormin’ Semi on a long grade.
Now GM may think that would cost them some battery life – I admit I dunno. It’s a much simpler scheme to implement and if you think about it a little bit I think you’ll see what I mean. If they want to do all this other stuff so you stay near 30% when you get back to the garage, Ok. But if the Volt can know its destination and the intervening elevations it can still charge you up to the correct level to get you there at 30%. An analogy, the Volt 3 rpm load matching scheme is like adding a quart of fuel to a tank at a time. I’m saying, you know you are going to use a full tank so fill ‘er up. It’s a simpler approach and it eliminates problems with hills as much as is possible.
November 13th, 2009 at 2:34 pm
It is crazy high. The program just went into effect a couple weeks ago. It pays 80 cents per (up from 42), and is locked in for 20 years, on systems under 10kW. I close a new place in January…already pricing out a 9.8kW system, lol. I’ve missed solar.
It definitely won’t pay for itself in a year though…are you producing power by solar or wind? I can’t figure out how you get a ROI after 6 years @ 12 cents.
I’m not sure if I am going to be ‘hands on’ this time or not. I’ve been pricing out doing it the lazy man’s way and turnkeying it, and it is working out to be about $5/watt. Payback would be around 5 years…which is still great, the old system was more like 9-10 up here. Most US states take between 15 and 20 years to break even.
November 13th, 2009 at 11:50 pm
Wrong.
The 2MT70 transmission is not a standard shifting transmission, and the guts are not missing. Its an extremely costly and complex mechanism developed for hybrid electric traction involving a power integrator. GM would never install such a transmission only to disable it.
Lets all stop dreaming. The Volt is a parallel machine (at some rare times it may act serial though), but the Volt is NOT a simple serial EV.
November 14th, 2009 at 12:08 am
Statik, that is $70,000 annual revenue. At $5 a watt, what will it cost to deliver 10 KW day and night long (with storage)?
November 14th, 2009 at 8:34 am
I’m not sure, but you have a math whoopsie in there somewhere (I think your using the cost ($5) as the modify on the payment per kW.
I banged my math out below so you could see it. Basically it works out to pay for itself in about 4.5 years, then you start get checks in the mail, (=
Cost of System: $5(ish)x9.8kW=$49,000
Revenue per Day: 9.8kWhx 4.2 (solar hours-avg)= 41.16x .9 (losses in the system)x.80cents=$29.37
Revenue per year: $10,720
Estimated payback on System: 4.57 years
November 14th, 2009 at 9:03 am
Good to see you back statik. You’re right about the poor payback times in the US, but for me it’s about the initial cost. I took a job just to help make ends meet, which is why I’ve been pretty quiet lately on the board.
Great to see all the LJGTVWOTR’s!!
Be well,
Tagamet
Let’s Just Get The Volts’ Wheels On The Road!!**********NPNS
November 14th, 2009 at 12:14 pm
Just noticed this post on the Voltage web site: “I have no idea why Alex Cattelan was so obtuse in this interview. It is very clear that there is no mechanical coupling between the generator and the traction motor. She made things sound much more complicated than they actually are:
During AER all the power comes from the battery and the generator is not running.
When battery is below 30% the generator powers the traction motor under most conditions (note it does NOT charge the battery).
Under some conditions like acceleration or going up hills, if the generator cannot supply all the power required, the battery may assist. Under these conditions the battery will drop below 30% charge.
If the battery is below the 30% level and the generator has extra capacity (i.e. not going up hill) then the extra capacity will be used to bring the battery back up to the 30% level.
The “coupling” she refers to is when the generator is directly powering the traction motor and not charging the battery. ”
The person posting has a handle called “innovator”. Sounds like an engineer working on the Volt.
November 14th, 2009 at 6:14 pm
A very strong “Thank you” Mr. JohnK.
I think it’s a great idea to come back a few times to each previous thread to see what final commentaries become posted. There often are exceptional clarifications at the very end of the thread here, often missed as the majority of readers move on.
Technical thinkers are very often less technically-clear at the end of a very long workday when additionally-tasked to extend expressive clarity for questions posed.
The technical mind is not some sort of infinite-thinking-capacity/peak-productive computer that we expect of hardware. (Peak technicians intellectual performance is 4 analytic/clearly-expressing hours per day for the deep technologies such as this one). (The remainder of the workday is routine administrative tasking).
As well, only over a long period of time (12 hours to 16 hours per project) can we can then expect to have a conclusive pattern of results of an overall performance from exceptional thinkers assigned to the complex technologies.
In short, it takes a really long time to get to know technical people sometimes. But it is always worth it!!
Thanks again, JohnK.
November 19th, 2009 at 9:12 pm
I would like to hear a little bit about how the intensive use of, for example, air conditioning plus stereo plus lights would affect Volt’s sustaining mode and depleting mode.
Let’s say you are in a very cold weather and need calefaction intensively.
Would Volt still go for 40 miles while in pure electric mode?
November 22nd, 2009 at 12:36 am
Full performance 100% of the time!! Hooowa! Perhaps look into a Camaro SS or Mustang GT. If electric propulsion is really that important the Tesla fits the bill. I don’t think the Volt is right for you, and by all means stay away from the disappointment of a Prius or heaven forbid…Insight.
November 22nd, 2009 at 12:59 am
Perhaps, although it hasn’t been a marketing challenge for the Prius or at a much smaller scale for the Tesla Roadster. Besides who in NA cares about what the Stig and Clarkson do anyway?