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Volt Will Get More Than 32 MPG in Charge-Sustaining Mode

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A question that remains unanswered by GM is what the Volt’s MPG will be in charge sustaining mode or while the generator is running.

When the Volt concept was first unveiled math models put it at 50 MPG, however since development began in earnest GM has kept silent about what it is actually turning out to be. The only thing everyone has heard by now is that city drivers could expect an average of 230 miles driven for every gallon of gas used over time, assuming a daily full charge.

However, when going on road trips for distances significantly greater than 40 miles it is still important to know how much gas the Volt will use in that setting.

The last time I asked Volt engineer Andrew Farah this question he said the MPG will “not significantly” differ from 50 MPG.

When we ran a poll on the topic here in August, 58% of 1549 voters predicted it would be less than 50 MPG, with the majority choosing 40 to 50 MPG range.

The question was recently asked of Tony Posawatz, Volt vehicle line director, by a Fox news reporter who actually had a good understanding of the car’s engineering. The video of this interview at the bottom of the post is well worth viewing.

When asked what the Volt’s MPG will be in charge sustaining mode Posawatz responded:

“We’re still testing that in all honesty, but we can make the following statement. It will be better than any conventional car in the class and we’re trying to figure out how close or if it will be actually better than other hybrids.”

According to fueleconomy.gov, the car with the best fuel economy in the small car class is the Toyota Yaris which gets 29 MPG city and 36 MPG highway for a combined fuel economy of 32 MPG.

Though Fox as a result of the interview reports“Chevy Volt to Get 32 MPG?” Posawatz seems to clearly state it will be more than that.

http://gm-volt.com/2009/10/25/chevy-volt-w...ustaining-mode/

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I'm sorry, but I cannot in good faith believe anything Fox News reports.

I should also mention that most news agencies I cannot believe in good faith either.

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I hope for GM's sake that whatever the test the EPA comes up with for the Volt will deliver better than 32mpg, or even 40-50mpg. That would be an absolute bitch to advertise.

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Doesn't the Equinox do around 32 mpg?

"The Volt: with an estimated fuel economy as good as a larger, less expensive CUV!"

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Just more useless conjecture.

Anyway, at least they're on the right track and asking the right questions.

The Volt is a vehicle that gets xx mpg and is able to drive xx miles on electric only with a full charge. Not the Volt gets 230 mpg if you charge it every night and then only drive 50 miles. Lol. 230mpg. It's like they're assuming Americans are too stupid to understand how the car works so they'll just give us one simple black & white number, even though it won't be accurate and barely scientific.

Edited by siegen
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At least in its first generational form, the Volt is not going to appeal to rural or long distance drivers. Its greatest strength is in being able to charge the vehicle for under a buck and drive to work once or twice on that, within the distance that 70% of the urban commuters do. The Prius' highway numbers are not spectacular, either.

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At least in its first generational form, the Volt is not going to appeal to rural or long distance drivers. Its greatest strength is in being able to charge the vehicle for under a buck and drive to work once or twice on that, within the distance that 70% of the urban commuters do. The Prius' highway numbers are not spectacular, either.

Funny, as I see most people using their Volt like a Prius for a long time... as rural or long distance drivers are going to have to gas up and most urban drivers, except those with a dedicated parking spot, are going to have to wait until the big cities put in some sort of charging infrastructure... which I think will be a long wait.

My GF has a situation that works for the Volt... owns a condo with a garage in Brooklyn, and rarely ventures outside Brooklyn and Staten Island... so a Volt would work for her without nary a drop of gas for months. She can afford it, as well. But I think she is in the vast minority.

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It better get more than 32 mpg, otherwise people will get a Fusion Hybrid or Prius. The Prius gets a combined 50 mpg, that is the number the Volt has to beat when burning gas. If they can get 40 miles off electric, then 50+ when burning gas, they have something they can sell. Basically, the Volt has to be a better deal than a Malibu + $15,000 for gasoline.

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I agree 32+ won't cut it as a competitor to its biggest rival for its class the Prius unless it is a big plus. It also is expected to have a much higher price tag.

Why is it that for every high mileage battery/electric plus gas car is designed for primarily short city driving? The people who need the high mileage are the ones who drive the farther distances.

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Take no notice of this. You have a reporter who does not know cars reporting on a Engineer who is tuning a car that he has yet to find the limits nor can he say yet what it will do.

At this point we know it will be better than 32 MPG and how much remains to be seen not just by us but even GM. THe car is only about 70% complete and still is doing a lot of testing, reprogaming and adjusting.

Just to note the Cruz is said to get 44 MPG in high mileage form. I would think we would see that as highway mileage and or better with some electric help with that. But this is all being sorted out.

Edited by hyperv6
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More...

Bob Lutz Implies Chevy Volt Will Get Between 40 and 50 MPG in Charge-Sustaining Mode

October 27th, 2009 | Posted in: Efficiency, Generator

GM vice-chairman Bob Lutz was interviewed on Fox Business News. The entire interview can be watched at the bottom of the post.

Just as vehicle line director Tony Posawatz was asked by Fox the other day, Lutz was also asked what the Chevy Volt’s MPG will be when it is running in charge-sustaining mode, after the first 40 all-electric miles have been driven.

As someone who has followed this Volt story since day one, along with many of you, I have found that Bob Lutz cannot help but be honest. GM has never officially acknowledged this number though at the time of the initial concept revelation they mentioned 50 MPG was the goal. However, in those days the generator was to be a 1 L turbocharged 3 Cylinder, and not the normally aspired 1.4L 4 cylinder it turned out to be.

When now asked what the Volt’s fuel economy would be in charge sustaining mode, Lutz replied as follows:

We haven’t published it and it’s not finalized. Once it’s running on pure gasoline it will be like a highly economical vehicle in that size class. It will be exceptionally good mileage but it obviously won’t be comparable to what it is when it runs on electric.

The vehicle is conceived primarily for urban or suburban use. It’s for that 80 percent of Americans who travel 40 miles or less per day; they will never use a drop of fuel. If you have a 60 mile commute, you’ll have 40 miles purely electric, the remainder of the mileage on very good gasoline mileage, and your average fuel economy will be somewhere between 120 and 150 miles per gallon.

So let’s do the math.

On a 60 mile commute, the first 40 miles are electric and the next 20 are on gasoline. At an average of 120 mpg, that would mean 0.5 gallons are used in those 20 miles (40 mpg). At 150 mpg, it would mean 0.4 gallons are used in those 20 miles (50 mpg).

Thus the Volt will average between 40 and 50 mpg in charge sustaining mode. Good enough for me, how about you?

Thanks to Philerup for the tip!

http://gm-volt.com/2009/10/27/bob-lutz-imp...ustaining-mode/

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At least in its first generational form, the Volt is not going to appeal to rural or long distance drivers. Its greatest strength is in being able to charge the vehicle for under a buck and drive to work once or twice on that, within the distance that 70% of the urban commuters do. The Prius' highway numbers are not spectacular, either.

The Prius has both the best highway and city fuel economy of any car sold in the US or Canada.

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This is the target I was expecting and hoping for. I assumed it needed to do better than 40 MPG and the closer to 50 MPG the more appealing it will by to the hypermilers.

First, we should take a look at the source. Lutz shoots from the hip, and his aim shows it. Very often he's been overly optimistic.

One of his tricks is to only talk about what he hopes the result will be in the most optimistic case. For the Volt that would be city driving, no AC/heat, no passenger, no cargo, nice weather, etc. If there is some truth in this (and I suspect there is), Lutz is hoping for 40+ MPG city under those circumstances. I haven't seen the clip, but I suspect the engineer that dropped the 32MPG+ hint was dealing with things that Lutz doesn't generally bother with... realities such as EPA methedology, highway, etc.

To put Lutz's example in context:

Lutz said: 40 miles electric + 20 miles ICE = 120 to 150 MPG Total (40 - 50 MPG ICE)

More realistic City Numbers: 32 miles electric (as per epa) + 28 miles ICE = 64 - 86 MPG Total (30-40 MPG ICE)

Highway: 25 miles electric + 35 miles ICE = 43 - 60 MPG Total (25-35 MPG ICE)

Note that 30-40 City and 25-35 highway still fits in the range indicated by the engineer.

Edited by GXT
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Just to note the Cruz is said to get 44 MPG in high mileage form. I would think we would see that as highway mileage and or better with some electric help with that. But this is all being sorted out.

A lot has been said of the Cruz. It will be interesting so see where reality lies. I suspect a lot of expectations are based on the Cobalt XFE, which, from the reviews I have seen, doesn't come close to delivering the EPA numbers.

However I wouldn't assume the Volt will do better than the Cruze. The Cruze will likely weigh in around 2900 pounds. The battery + motors/generators + etc. of the Volt will likely weigh 500 pounds (the battery is 400 alone). That is an increase of 15-20%.

Plus the Volt will suffer from conversion losses not experienced by the Cruz.

On the flip side, the Volt will have the ability to reclaim some energy while stopping... although that won't apply in the "44MPG" highway situation.

Plus things like AC, heat, stereo, etc. may have a greater impact on the Volt.

I suspect you are right that things are being sorted out. But I also suspect that the relative silence on the matter indicates they are falling well short.

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A lot has been said of the Cruze. It will be interesting to see where reality lies.

Reality is already here. In Europe.

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A lot has been said of the Cruz. It will be interesting so see where reality lies. I suspect a lot of expectations are based on the Cobalt XFE, which, from the reviews I have seen, doesn't come close to delivering the EPA numbers.

However I wouldn't assume the Volt will do better than the Cruze. The Cruze will likely weigh in around 2900 pounds. The battery + motors/generators + etc. of the Volt will likely weigh 500 pounds (the battery is 400 alone). That is an increase of 15-20%.

Plus the Volt will suffer from conversion losses not experienced by the Cruz.

On the flip side, the Volt will have the ability to reclaim some energy while stopping... although that won't apply in the "44MPG" highway situation.

Plus things like AC, heat, stereo, etc. may have a greater impact on the Volt.

I suspect you are right that things are being sorted out. But I also suspect that the relative silence on the matter indicates they are falling well short.

Extended-range fuel economy would probably be spectacular, if the engine could directly turn the wheels, it seems. The Prius manages 50 mpg combined with a 1.6 kWh battery pack. Imagine if it had a 16 kWh pack that could properly capture *all* the regen.

According to Ford, their 10 kWh plug-in Escape Hybrid gets 88 mpg city and 50 mpg highway in traditional hybrid mode! In plug-in mode, it gets 120 mpg for the first 30 miles.

It seems like all the extra energy storage in the Volt should *increase* extended-range fuel efficiency, not hinder it.

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Reality is already here. In Europe.

Saw one yesterday here in Lisbon... a Taxi!

We don't get the turbo 1.4L engine. It will be offered on the Astra but not on the Cruze. For now at least.

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I would feel the addition of the 1.4 Turbo and a six speed in the Cruze will do well but in the Volt tied to the electric drive system should see also some good numbers when it has to run. If those numbers are not as good or better than the Cruze than GM will have a marketing issue here.

I suspect when the car is on gas it will do well on MPG but will just not have the zip of the full electric mode. This is based on early reports on the Volt by the engineers who are working on it. It will be a car that many here will want to keep in electric mode to keep performance to what we would expect. I just hope the gap is pretty close by production time on the two systems.

Edited by hyperv6
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I would feel the addition of the 1.4 Turbo and a six speed in the Cruze will do well but in the Volt tied to the electric drive system should see also some good numbers when it has to run. If those numbers are not as good or better than the Cruze than GM will have a marketing issue here.

I suspect when the car is on gas it will do well on MPG but will just not have the zip of the full electric mode. This is based on early reports on the Volt by the engineers who are working on it. It will be a car that many here will want to keep in electric mode to keep performance to what we would expect. I just hope the gap is pretty close by production time on the two systems.

It should do better in City, but not in Highway. The marketing solution will probably be what they have been doing to date:

1) only talk about city without expressly mentioning you are only talking about city

2) use yearly averages ("230 MPG")

3) use trip averages (40 mile electric + 20 mile ICE)

4) don't use the EPA methodology at all ("up to 40 miles")

5) If really trapped, talk about city/highway combined numbers or send in Lutz to give his "close enough for plausible deniability" answer.

Regarding not having the zip of full electric mode... are you suggesting they are going to intentionally limit power use on the ICE? The Volt generator is already only 71 HP so it isn't like it can afford to be de-rated much more.

I imagine one thing they are considering is tapping into the 8KWh dead-weight reserve to get the MPG numbers up and then and dealing with all the early battery failures later.

Edited by GXT
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It should do better in City, but not in Highway. The marketing solution will probably be what they have been doing to date:

1) only talk about city without expressly mentioning you are only talking about city

2) use yearly averages ("230 MPG")

3) use trip averages (40 mile electric + 20 mile ICE)

4) don't use the EPA methodology at all ("up to 40 miles")

5) If really trapped, talk about city/highway combined numbers or send in Lutz to give his "close enough for plausible deniability" answer.

Regarding not having the zip of full electric mode... are you suggesting they are going to intentionally limit power use on the ICE? The Volt generator is already only 71 HP so it isn't like it can afford to be de-rated much more.

I imagine one thing they are considering is tapping into the 8KWh dead-weight reserve to get the MPG numbers up and then and dealing with all the early battery failures later.

I expect them to push combined and city. But the main focus will be the 40 miles all electric.

The interview I read said that the car on gas will just not have as much power as it will under electric. THey quoted HP ratings and it was down. Also the RPM would be rather high to keep the electric flowing in high demand. But this was a few months ago and recent work may have addressed this.

The high RPM's were an issue because of noise. They figures with the car quiet under electric mode then under gas generated power it would be of some concern.

It will be interesting if GM tells how they deal with many of the issue this car has that normal cars don't we only get snips of what issue they have had to deal with. I remember the first one I read about was old gas in the tank. They said at one point they needed to address the gas in the cars that were only driven to work and home on electric and seldom used the gas. The fuel has a shelf life and could degrade in some cases. I noted on cold start it will fire the engine up so I expect it may hace some kind of engine cycle system. I know our Home Generator cycles once a week for 15 min just to keep running and ready.

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I expect them to push combined and city. But the main focus will be the 40 miles all electric.

I also think they should focus on the 40 miles electric, however if they have to advertise the EPA numbers (and I think they do), then 32 miles city and 25(?) highway isn't going to look so good. I suspect that is why they want to talk about the 230MPG number... however I think that will really bother consumers. Look at the outcry about the Prius numbers when it was rated at 80MPG and "only" got 50. 230 to 35 is so many times worse.

The interview I read said that the car on gas will just not have as much power as it will under electric. THey quoted HP ratings and it was down. Also the RPM would be rather high to keep the electric flowing in high demand. But this was a few months ago and recent work may have addressed this.

Under gas it is supposed to perform the same as under electric. Apparently the generator cannot produce enough electricity to keep up with the motors under heavy draw, but that is one of the reasons that the Volt turns on the ICE with 30% of the battery capacity remaining. Theoretically a driver needs significant HP only in spurts, and when the demand exceeds what the generator is able to produce the Volt will dip into that battery reserve to maintain performance.

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