GM-VOLT : Chevy Volt Electric Car Site

Your Range Will Vary

We have long heard that GM is targeting a 40 mile electric only range and a 300 mile gasoline range for the Chevrolet Volt.

Engineers have repeatedly said the Volt is meeting range expectations and have explained that the 40 miles can be achieved both on the city and highway cycles, which is fairly non aggressive, and doesn’t take into account significant electric accessory draws.

According to GM vice chairman Bob Lutz, the Volt’s electric range will vary considerably in the real world. He noted that some customers could become unpleasantly surprised and even “perplexed” at how drastic the range will be reduced under some driving conditions.

Though GM has in place special provisions to allow the car to be maximally consistent in range delivery, physics are physics, and 8 kwh is 8 kwh.

Lutz told a reporter from the Dow Jones that he drove the Volt for a weekend recently during the cold Detroit winter, and found he got only 28 miles of electric range.

Of course, with the Volt this will be far less important then in pure EVs, as the range extender will always be there to kick in and keep drivers going.

Pure Electric Volt

On the flipside, Lutz also told reporters at the Auto Show that GM is planning to build a pure electric version of the Volt too. This will be for that segment of people who want it and to compete against such vehicles as the Nissan Leaf.

For as long as the Volt concept has been in existence a certain contingency of people have expressed interest in such a vehicle as many comments on this site over the years can attest.

Lutz wouldn’t say when such a car would hit showrooms, but noted the process for building it would be “technologically trivial,” and just a matter of removing the range extender and expanding the battery pack.

“Once you’ve done the Volt, pure electric is trivial. You just leave some parts out,” Lutz said.

Source (ABC News)

GM has talked tirelessly abut how aerodynamic the Volt is, how its shape was born from the wind tunnel, and how important aerodynamics are for the car to achieve its 40 miles all electric range.

Yet for all that talk, the company has never released any official figure for the vehicle’s coefficient of drag (CD). This is the numerical measurement that indicates how slippery a car is, and unlikely to be slowed by wind resistance.

Bob Boniface who is chief of Voltec design finally provided us the details that were obtained when GM measured the Volt and its competitors on its own wind tunnel.

“We had the comparably-equipped 2010 Prius with 17 inch wheels, and the new Insight,” he said.

“The Prius came in at .30,” said Boniface. “That was a number that was verified in our tunnel, in Chrysler’s tunnel, and in Ford’s tunnel.”

“The Insight was 0.32, and the Volt was .28,” he said.

“I’d like to test the Volt in the same tunnel where Toyota got their 0.25 value,” he teased.

He expanded:

This number is for the Volt IVer which is representative of our production car. We were resistant to give out the number earlier for two reasons. One we wanted to wait until we tested our IVer. Also, we didn’t want to report it out until we saw where the competition was because we know that those numbers depend on how the tunnels are calibrated.

If I quoted 0.28 a year ago people would have said ‘aha’ the competition got 0.25. But its really all relative to what tunnel it was tested on.

The base Prius with the smaller wheels may come in lower, but we don’t offer 15 inch wheels.

EV-1
According to GM’s aerodynamics engineer Nina Tortosa, the old method of testing yielded .19, but with current testing methodology it would equate to .21.

“But that vehicle didn’t have a rollover and frontal impact structure of today’s standards,” said Boniface. “You could not sell that car today. That’s not to say we wont get to .21 again with another car. We always try to get drag down but we have to protect our styling flexibility.”

Corvette
The current base Corvette is the most slippery and its a 0.29, slightly less aerodynamic than the Volt.

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!

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.

One question the Volt engineering team is often asked by journalists is how much accessory electric draw will effect the Volt’s 40 mile all electric range.

Clearly there will be an effect.  During the recent 30 to 40 degree mornings I, for example, have been driving my MINI E electric car with the heat on moderately for the first time since I got the car in June.  This is resulting in around a 10 to 15% decrease in range.

Conventional gas cars are able to use the heat of the gas engine to heat the car but pure electric cars and the Volt in EV mode don’t have that luxury instead having to rely on electric heating elements.

Indeed GM announced in August that using some unspecified average amount of HVAC and city driving schedule, the Volt would achieve 25 kWH/100 miles.

As was reported yesterday, a fleet of eight integration Volts are currently on a three day extended test drive which will total 1200 miles of driving.

Among many other things, engineers have been testing the HVAC and Volt engineer Andrew Farah explains how the Volt will handle this issue when he was asked how HVAC draw will affect range.

There is going to be an effect , there is no question about it. What we’re trying to do is give the customer an opportunity to decide how much they want it to have an effect.

For example, one of the things that the Volt has that other cars don’t is not only do you select what temperature you want and things like that, but you can also select if you want it to use full available power because you’re interested in being 100% comfortable 100% of the time, or whether or not you want to restrict how much power the system can use.  Yes that will take a little longer to heat or cool the cabin, but again it really has to do with what the customer is interested in doing. We try to make it easy for them to make that kind of choice.

So it seems the Volt will let you dial in an economy HVAC option to extend your EV range if desired.  It is also believed that the Volt will be able to programmably precondition the temperature of its cabin while plugged-in, using grid energy, therefore requiring less energy from the battery once driving begins.

So what are the priorities of we early adopters?  Will you choose to limit your HVAC power to extend range, or just go for sheer comfort?

The Chevy Volt has two configurable LCD screens, one behind the wheel where traditional gauges are typically found, and one atop the center stack. The latter will also be a touch screen. I have seen it in person in a pre-production car and was very impressed with its crispness, vividness and high definition.

We understand a lot of information will be available on those displays, they are configurable, and the driver will be able to choose among many options.

A primary function will be to provide the driver with feedback on how fuel efficient he/she is driving and utilizing accessory loads such as HVAC.

As anyone who like to hypermile hybrids knows, seeing real-time instantaneous MPG is a useful measure to adjust driving behavior as one moves along varying road conditions.

I asked Tony Posawatz who is the Volt vehicle line engineer if that value will be provided while the car is running in charge-sustaining (generator) mode.

“I don’t think we will show instantaneous mpg,” he said. “We are working a lot on what information to show and how to present it right now.”

“The OnStar capabilities with VOLT will be mind boggling,” he said. “Stay tuned.”