GM-VOLT : Chevy Volt Electric Car Site

On Thursday, December 24th, I took delivery of my Chevrolet Volt. I opted for Cyber Gray Metallic with black leather and dark accents. Shortly after my delivery, I drove approximately 400 miles to northern New Hampshire to visit with family for Christmas. While I intend to write some future posts about my delivery experience and subsequent long trips (including a soon-to-come 375 mile trip to Central NY), I wanted to take a moment to write this review about the Volt’s performance in snow.

As I arrived to visit my family, I was greeted with about 2-3 inches of loose snow pack on all the roads. I was a little worried that I may be sliding around with the Volt’s low rolling resistance tires. As I started to drive around in the snow-filled streets, I was pleasantly surprised to find that the Volt behaved more like a tank than a compact hatchback.

This particular town in New Hampshire has a fair amount of hills as well, and despite the snow and hills, the car seemed to accelerate effortlessly in anything I threw at it. I could get the traction control light to blink if I floored the car, but that was expected. Otherwise, I was able to accelerate as quickly as I wanted, and the car handled the conditions effortlessly. It was amazing. I have not had any experience in freshly fallen snow just yet, but so far I am very impressed. My previous vehicle, a Honda Civic, would’ve spun a fair amount in these conditions even with snow tires, and the same is true for my relative’s SUV and pick-up truck.

I also had my father and uncle both test drive the Volt within the past day or two. My uncle, who at first expected some sort of golf cart in the garage, commented, “it’s like a real car” after driving it. (Of course it is! Here’s a good example of how we can all help to dispel the electric car myths and show people what the Volt is really capable of.) When trying the vehicle on snowy hills and trying to accelerate faster than he expected the car to be able to handle, the Volt continued to perform effortlessly, and he then commented, “it’s as if there’s no snow at all”.

Needless to say, both my father and uncle were impressed with the Volt’s handling and ride quality, especially in the snow. I was consdering getting snow tires, but at this point I’m content in using the all-season tires and the Volt’s stunning traction abilities.

I’ve also posted a video below showing the Volt negotiating up a steep grade, stopping, and then resuming up a hill. The hills don’t look as steep in the video as they really are, but hopefully it helps get the points across.

I hope to have more posts about my Volt experience in the near future, here as well as in my forthcoming VoltNation blog.

Happy Volting!

Drivers of the 2011 Chevrolet Volt have three driving modes to choose from; normal, sports, and mountain mode.

The mountain mode is rarely used.  It acts to cause the range extender turn on at higher charge point of the battery.  This allows a deeper battery reserve for use when travelling up a long steep grade.  In nearly 2000 miles of driving I have never found the need to use it.

When the car is powered on it is in regular mode by default.  This provides a standard accelerator experience. Pressing the drive mode button twice causes the car to shift into sports mode.  Once engaged the driver will feel the car surge forward, and it becomes much more spirited in acceleration.

GM Volt director Tony Posawatz once mentioned that the car would get the same efficiency or EV range whether the driver was in sports mode or regular mode.  Top power out put is the same 110 kw, and flooring the pedal produces the same response in both instances.

“On the various EPA federal test procedure cycles, the efficiencies are basically the same, says Posawatz.

It is true, though that driver behavior is a more prominent factor.  Aggressive use of the accelerator in sports mode will lead to more range reduction than the same use of the accelerator in normal mode.

“Sport mode may cause you to have a bit more fun and if you fully realize the fun opportunities, you will be a bit less efficient,” says Posawatz.

In my experience driving the car, I tend to prefer sports mode, and use it all the time.  Tony Posawatz also drives a captured test fleet Volt and uses it a bit differently.

“I have found that I use Sport mode and have fun when I know that I will make it to my charging station without using gas and with time to charge,” he said.  ”It is my guilty pleasure.”

“Similarly, I have changed my driving a bit to see if I can beat the “video game” and improve my numbers,” he added.

Braking is another issue.

When in D mode, the car softly coasts similarly to a conventional car when the foot is off the accelerator. L mode engages a strong regenerative drag when the foot is off the accelerator that allows the driver to simulate a downshift effect and get motor braking, sparing the disc brakes from wear.

It has been my preference to drive at speed in D mode, but when needing to slow or in stop and go traffic I use the L mode.

Posawatz explains that overall efficiency doesn’t differ much between these two settings either.

“Relative to D vs. L, there also is not a lot of difference in efficiency between the two,” he said. “Going down Pikes Peak, you want to be in L.”

“You want to use the coast of drive and then shift into L as you approach a stop, he added. “I use the L a lot because it is a more engaging drive, especially in Sport and on winding roads.”

In the latest installment of GM-produced two minute transparency videos, the company gives us a taste of what its like to test the Chevrolet Volt braking system.

Featured in the video is Performance Integration Engineer Valarie Boatman who describes how GM tests braking, stability, and traction control in Volt prototypes.

She notes that the stopping time test is very important and is measured as a pass or fail.  The Volt’s brakes she says “are phenomenal,” and they are much faster than the brakes in a conventional car.  This is because the Volt’s brakes use an accumulator which is more responsive and rapid than conventional vacuum-boost brakes.

Also measured is the ability to steer while braking and brake while steering.  In this test, she measures the car’s yaw rate or rotational behavior, which is also measured on a pass fail basis.

For stability control the car’s tendency to spin out of control is measured, and engineered to be kept at a minimum.

Traction control is measured by seeing how fast the car can accelerate without spinning the wheels too much.

On all counts the Volt delivers.

She notes the testing process just for the brakes ” takes months and months” of eight to ten hour workdays, just to get things right.  In the end though she finds working on the Volt “is a really cool opportunity.”

See video below:

Electric cars not only offer instantaneous torque but continue to provide linear acceleration throughout the driving velocity range. Torque and acceleration are greatest at the low-end and then flatten out as high speeds are reached.

One reporter’s observation of a 67% calibration Volt prototype on the highway brought into question highway performance.  As some here may know, I recently had the opportunity to experience a near-final Volt going from 55 to 80 mph ont the highway and although linear felt performance was quite acceptable.

Combustion engine cars operate differently. At higher speeds, if the driver floors the accelerator  pedal, the automatic transmission will shift down a gear, engine speed and torque will increase, and the car will accelerate.  Among the uninitiated, the lack of this type of responsiveness could disturb some would-be electric car buyers.

As far as I can tell, or know, the Volt does not simulate this experience.

However, according to a test drive from Edmund’s Inside Line, the LEAF does.  Apparently Nissan believes it was necessary to reproduce the passing gear experience in its electric car for greatest customer acceptance.

Edmund’s reports the following statement as attributed to Mark Perry who Nissan North American product planning and advanced technology director:

Engineers programmed the electronics to add a bit of power at the very end of the accelerator pedal’s travel, and when you floor the Leaf you do feel a little extra surge – not quite like having a passing gear, but enough to let you know the powertrain is responding to the signal your right foot is sending.

Edmund’s apparently did not get it quite right though with this description per a direct communication between Perry and GM-Volt.

“The (LEAF) electric motor still has sufficient torque to have good passing speed from 55 to 70,” Perry told GM-Volt.  There are “no gears or “step down.”  With respect to O’Dells comments, “he mixed two pieces of info but intention is correct,” said Perry.

Nonetheless, some other interesting comparisons between the LEAF and Volt were delineated in this review.

The LEAF, as does the Volt, has both a normal braking mode and an eco braking mode which gives the driver a little regenerative drag, allowing the car to be slowed without the brakes.  The LEAF, however, has only a normal and Eco power mode (slower) which determines overall driving power.  The Volt has a normal and a sports power modes, with the sports mode adding about 20 kw of power.  The fact that the Volt has more power and acceleration speed  may be part of the reason why GM engineers didn’t think a passing gear simulation was necessary on the Volt.  The LEAF motor’s peak power is 80 kw, whereas the Volt’s is 110 kw.  The LEAF has a CD of 0.29, the Volt’s is 0.28, the LEAF weighs about 3500 pounds and the Volt 3900 lb due to the presence of the gas engine.

A surprising point of the LEAF review is that Nissan allowed the journalist to take the test car up and down public roads in San Diego, even up to 82 mph.  GM has said it is legally “not allowed” to let anyone but GM employees drive Volt prototypes on public roads, and thus all media drives have taken place on pylon-lined parking-lot based test courses.  That is everyone expect Jay Leno, who for some reason did get to take the Volt on public roads.

The presence or absence of a passing gear simulation on an electric car is an interesting issue.  How important do you think it is?

Source (Edmunds)

I had the chance to ride in the Chevrolet Volt prototype that GM staff drove from Austin Texas to New York City on July 4th.

This particular prototype, called “a golden IVer” due to its proximity to a final production car, had been built in December 2009, and had nearly 10,000 engineering miles on it. The software controls were more than 99% complete according to Will Handzel, the GM controls engineer who actually drove the car. Interior surfacing was still a bit rudimentary and there was a bit of wear and tear inside.

This was my first chance to ride in the Volt (I had the passenger seat) in real-world highway driving situations, though I have driven it for about an hour, sub-50 mph around around a test track.  We took the car about 15 miles from Liberty Park in NJ to midtown Manhattan.

I found the car very cheerful, pleasant and bright. It was spacious and airy inside. Even though the day was bright and sunny, the LCD displays were very bright, crisp and vivid. I saw the OnStar navigation system in action and it worked perfectly, as did the handsfree phone and the capacitive controls, though Will felt they took a bit of getting used to.

When we started off in the car it had about 4 miles of EV range, and once again I missed the switchover to generator mode, never noticing it. The car was smooth and solid all the way. The only sound I could notice was from the fan from the air conditioning which worked terrifically, in comfort mode, on a day it was more than 95 degrees outside.

I specifically asked Will to demonstrate accelerating from 55 to 80 MPH, while we were on the highway. When I asked him, he said throughout his 1776 mile drive, and indeed all his Volt driving, passing on the highway was never a problem.  ”We never had an issue,” he said.  Acceleration from low speed and stop certainly wasn’t a problem, the car springs onto the highway with gusto.

Acceleration from 55 to 80 was strong and linear. There was no customary downshift effect people may be accustomed to in traditional vehicles, but, that really didn’t matter. The car swiftly made it to high passing speed in a constant and confident fashion.

Yes, this is different than a standard gas car, but in my opinion represented no trade off or loss of function. It worked wonderfully well.

It was also very quiet while driving.  After getting out and standing aside it, while it was idling in the heat, the engine could be heard running.

Still no final word on final fuel efficiency numbers, as GM still says they are being negotiated with the EPA, but obviously will be finalized and made public soon. Expectations are that fuel economy will be somewhat above that of the best-in-class standard gas compact car.

In conclusion, there are no surprises here, the car handles capably in the highway setting.

You can check out my experience in the video below:

The Opel Ampera is the identical sister car to the Chevy Volt only sporting Opel design cues.  It will be built side-by-side with the Volt in Michigan for export to Europe where it will go on sale in 2011.

Like the Volt, only a little later, Opel is beginning to allow journalists to test drive an Ampera. Famed British publication Telegraph had its chance at the wheel and author Andrew English has produced an interesting review.  GM has been careful to only allow journalists, myself included, the chance to test drive Volts at modest sub-50 mph speeds, limited to pylon-flanked parking lot impromptu tracks.  English had the chance to take an Ampera out on the highway.

He was pleased with the spacious and attractive interior calling it “comfortable, classy and commodious.”

He found acceleration strong noting the car “charges hard” up to 50 mph. After that he perceived, “the single-speed electric motor’s flat torque curve has begun a nose dive and acceleration at high speeds is poor.” Perhaps this is why GM hasn’t allowed US drives beyond 50 MPH. That was the fastest speed I could hit on a roughly half mile track, though one US reporter was said to take a Volt to 92 MPH at the Warren Tech Center, on a side road.

English suspects the perceived power fade at high speed is because the Volt/Ampera’s top speed is100 mph which is lower than most similar-sized gas sedans which is typically 130 mph.

He claims GM has a solution forthcoming:

General Motors is working on the problem and this autumn plans to unveil a mechanical direct-drive from the engine to the front wheels through the existing twin-clutch planetary gearbox. This would reduce the energy losses of turning petrol power into electricity to drive the car at high speeds, and would also give the Ampera more spritely overtaking performance.

This claim, if true, is rather shocking because it flies in the face of everything GM has said in the past and would mean the gas engine could power on even during the first 40 miles.

I reached out to Volt spokesperson Rob Peterson who with utmost respect for the reporter denies this is the case.  He also notes the Ampera English drove is a 65% calibration build, whereas current Volt test cars are at a much more refined 99%.  This is what Peterson had to say about the powertrain change claim:

This report is inaccurate. First off, the Volt cannot be driven without electric power. It always makes use of electric power within the drive unit.

Secondly, we have no plans to make any mechanical or control strategy changes prior to launch.

The team is in the final stages of validation and durability and have not identified any reason to make any changes. We have a very innovative drive unit that includes a number of clutches and a planetary gear-set which is highly efficient and exists in our pre-production vehicles today. For competitive reasons we won’t provide more details on the operation at this point, but will soon.

Source (Telegraph)