• Nov 30, 2009
2011 Chevrolet Volt – Click above for high-res image gallery

Three years ago this December we first walked into a Manhattan conference room for a background briefing on a new concept being developed by General Motors for the upcoming Detroit Auto Show. Earlier that year, the release of a documentary called Who Killed the Electric Car made the then largest automaker in the world the subject of some well deserved criticism for its handling of the end of the EV1 program. The movie and announcement of the all-electric Tesla Roadster lit a fire under GM to get back into the plug-in electric vehicle game.

What we saw that day in NYC was a description of a new powertrain architecture then dubbed E-Flex. GM folk on hand that day included vehicle line executive Tony Posawatz and former VP for environmental affairs Beth Lowery. They explained that among the biggest lessons learned from the EV1 program were that range anxiety and lack of practicality would make a car like EV1 nearly impossible to sell in the mass market. The engineers went back to the drawing board to address those issues and came up with the extended range electric vehicle, or ER-EV. The Volt concept was approved for production mere months after it was revealed at the 2007 Detroit Auto Show. At this week's LA Auto Show, GM is publicly showing the production intent version of the Volt. Before that, however, we were among the first to drive a Volt with its range extender running. Read all about it after the jump.



Photos Copyright ©2009 Sam Abuelsamid / Weblogs, Inc.
We've had two previous in-motion experiences with the Volt. Last April we had the opportunity to drive one of the powertrain mules, which put the renamed Voltec powertrain into the body shell of the Cruze that shares its platform with the Volt. In August we got to ride (not drive) in one of the pre-production Volt integration vehicle engineering release prototypes (IVERs) with now former global chief engineer Frank Weber.

We trekked out to Dodger Stadium on Sunday afternoon before this week's press days for the LA Auto Show for our session with the actual preproduction Volt. Chevrolet set up a driving loop in one of the parking lots where we got to try out a variety of different maneuvers with the car. This time we would get to actually drive the pre-production car from pure battery power to its charge sustaining mode.



The Volt has evolved significantly over the past three years. We've all the heard the story about the first wind tunnel evaluations of the concept and how it purportedly performed better backwards than forwards. While that may be somewhat of an exaggeration, the concept was bad in terms of aerodynamics. In production form, this new body is proclaimed to be the most aerodynamically efficient car that GM has ever built, although the company is declining to say exactly what the final coefficient of drag number is. Like the concept, the production Volt is a five-door hatchback with seating for four adults.

In the spring of 2008 when we visited the GM wind tunnel in Warren, MI, we saw a 1/3 scale model of the where the Volt design was going, but it remained covered in duct tape. We did learn then that aside from the front fascia, perhaps the most important aspect of the shape was at the trailing edge of the car where the air separates. Looking back at the EV1, that car featured a long tear drop tail to help ease the air stream off. Because of the need to make the Volt a four-seater with a real trunk, that shape was not a practical alternative.



Instead, the aerodynamicists spent many hours in the wind tunnel carefully shaping that trailing edge to get the air to come off in a controlled fashion. The result is some interesting detailing at the Volt's hind quarters. A sharp edge runs vertically down each corner while a lump in the lower body also contributes, and a full belly pan empties out into a diffuser under the rear bumper. The overall effect with the rest of the car is a fairly aggressive stance and a surprisingly attractive overall shape. The only questionable element remains the thick black border under the side windows. We'd definitely prefer more side glass and a lower belt-line.

While most compact cars of this size have three rear seat belts, the reality is that only three small children will usually fit comfortably. The Volt is limited to two rear passengers because of the battery pack down the center tunnel, so you might need to leave the third kid home. However, behind the rear seat is a surprisingly cavernous cargo area made possible in part by the tall rear deck.

The basic powertrain architecture and specifications remains unchanged, but practical realities have made changes necessary. The originally planned 1.0-liter three-cylinder turbo has been supplanted by a 1.4-liter normally aspirated four-cylinder. The four-cylinder is claimed to achieve better fuel consumption than the triple, hence the change. The engine and generator also now sit out ahead of the traction motor instead of on top of it.



While the engine and its position have changed, the operating principle has not. As far as GM is concerned, this is an electric car. Only the 110 kW traction motor ever provides drive torque to the front wheels. When the battery reaches its "depletion" point of approximately 30 percent charge, the 100-hp engine kicks in to drive a generator. For the most part, the generator sends electricity to the electric motor that's driving the wheels. The engine mainly operates at constant speeds where it can be controlled efficiently. Since power demands can fluctuate, any surplus is fed to the battery, although the engine/generator is not specifically set up to charge the battery.

Because the battery can be drawn down to provide extra power beyond the capability of the generator for hill climbing or acceleration, the charging capability is used during off-peak demand only to replenish the battery to its "depletion point."

When we arrived for our drive session, the car was plugged in to get some juice back in the battery. Vehicle chief engineer Andrew Farah rode shot gun with us as we set out with the battery gauge indicating six miles of electric range. The driving loop consisted of a number of corners of varying radius, a couple of chicanes and a fairly long back straight along with two stop signs.



The car that GM made available was one of the 80 IVER pre-production prototypes built this past summer. Unlike the other IVERs, this one was cleaned up and finished for auto show display and media drives. Most inner surfaces of these IVERs don't have the proper graining that will be on production cars or the production light clusters, but GM pulled together enough prototype parts to make them look essentially complete. In addition, unlike most of the IVERs that were finished off in primer grey, this car was painted in the same silver-green color that was the subject of GM's color contest. The winner of the contest will be announced on Tuesday here in LA.

Like many modern cars, the Volt doesn't uses a fob instead of a key with a start/stop button on the left side of the center stack next to the shift lever. Pressing the button produces a green glow from within. We shifted into Drive and rolled out silently with the Volt running purely on battery power as we circled the loop trying to run down the battery so we could experience the charge sustaining mode.



While sucking the juice out the battery, Farah pointed out some of the features in the car. Above the start-stop button are two other buttons with Leaf and Sport labels. It turns out that the default operating mode for the Volt actually limits the maximum output of the motor to 90 kW (121 hp) in order to help maximize efficiency. The Sport mode releases an additional 20 kW bringing the output up to the full 145 hp. Even in the normal mode, the instant torque of the electric motor means that the Volt feels strong accelerating from a stop. We didn't do any official timing, but with Sport mode engaged, the Volt certainly felt like it could hit 60 mph in the mid-eight second range.

When we drove the Cruze mule last spring, the electric drive system behaved pretty flawlessly except for a couple of hiccups with the brake system, which is a fully blended system that combines friction braking with regenerative braking. We specifically looked for those hiccups in this Volt and couldn't get the brakes to misbehave. Farah acknowledged that there are still a few glitches in the brake software and calibration work is still being done. Even at this point, 11 months from Job 1, the brakes feel better than they do on many hybrids using the same system.

Another feature of the Volt is the Low position on the shift lever. The Volt doesn't actually have a transmission as such, just a reduction gear. There is no actual low gear. The Low position provides increased regenerative braking when the driver lifts off the pedal. In Drive, lifting off gives about 0.1 g of regen braking, similar to what you get in a conventional vehicle from engine braking. In Low, the lift off regen is boosted to about 0.25-0.3g, about what you get from downshifting. The main purpose of this is to save the brakes when going down a long hill.



Eventually the battery meter dipped down toward the 0 miles left point. When running on the battery, a battery meter dominates the left side of the LCD display with the ghost of a gas gauge above it. As the car switches from charge depleting to charge sustaining mode, the gauges switch place. On the right side of the display is a power gauge. A mode button on the left side of the dash swaps the energy gauge over to the other side and eliminates the power gauge for a simpler layout.

Getting into charge sustaining mode doesn't necessarily mean the engine starts up right away. In fact there is nothing in the car that tells the driver that the engine is running. According to Farah, the intent is to make everything as transparent as possible for the driver. He tells us that the Volt team is designing the car for mainstream audiences rather than the hyper-miling crowd. They wanted people to just get in the car and focus on driving rather than watching all the gauges and trying to eek out every last foot from a gallon of gas.



We didn't even realize the engine started for the first time until we came to a stop and heard it running. The most noticeable thing at first was when the engine shut off. Farah told us that the team was not yet satisfied with the engine shut-off quality and is continuing to calibrate it. While it was noticeable, we still felt the shut-down smoothness was better than many current production hybrids.

When we first talked to GM about the Volt three years ago, the thought was that the engine would simply run at a constant speed to maintain the battery charge. As development has continued, that strategy has evolved. The output of the engine/generator is based on the needs of the battery and motor, not what the driver is demanding. As the level of the battery changes, the generator is controlled to provide the necessary, electrical output. The engine speed in turn is selected to maximize the load on the engine. An engine runs most efficiently at full load. If the electrical demand is low, a lower engine speed is used in conjunction with the generator control to get the desired load.



Currently the engine can operate in a range of about 1,400-4,000 rpm. According to Farah, the maximum engine speed will likely be reduced as they finalize the calibrations, although he didn't say how much. As we continued running in charge sustaining mode, we were never able to feel the engine start and stop while the car was in motion. However, after a series of hard accelerations we were able to occasionally hear the engine running when it went into higher rpm modes. The sound was similar to or better than most other comparable compacts, but Farah was adamant that it was not good enough. Additional work is still being done both on the engine control and the general vehicle noise, vibration and harshness (NVH) properties to improve this. Farah admitted that more road noise was still coming through on these IVER vehicles, especially in the back of the car, than was desirable.

In terms of handling, the Volt felt capable but obviously we couldn't evaluate much in a parking lot. Body roll was reasonably well controlled, a behavior aided by have the 400-pound battery pack mounted low in car. In fact, according to Farah, the Volt's center of gravity ended up being about two inches lower than the Cruze. We did toss the Volt around a bit in the corners and it felt reasonably well balanced below 8/10ths, but that did turn to understeer as we pushed harder. Farah declined to say how much the Volt weighs, but he did tell us that weight reduction efforts have brought the weight of the base car (minus the battery) down to about the same as a comparable conventional car. So the Volt weighs about 400 pounds more than a Cruze, which should put it at around 3,500 pounds.



It's been a tough three years for General Motors since we first learned about the Volt. The automaker has gone through bankruptcy and emerged as a smaller company that is majority owned by the U.S. government. When we first wrote about the Volt, many of our readers groused that it was nothing more than smoke and mirrors, a simple publicity stunt. As we've followed the development since then, the proportion of people who think the Volt is vaporware has shrunk somewhat, although many still doubt whether the car can succeed commercially.

Now that we have driven the car in both charge depleting and charge sustaining modes, we can say that this car is definitely not vapor. The Volt is real and it certainly appears to work. Whether it can actually hit 40 miles on a charge, what mileage it will get in charge sustaining mode and how long the battery will last are questions that remain for another day.



Photos Copyright ©2009 Sam Abuelsamid / Weblogs, Inc.


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    • 1 Second Ago
  • 68 Comments
      • 5 Years Ago
      Good article, some questions: is there any info regarding GM hybrid plans or is Volt the only game in town till 2012? Do they expect people to be able to afford Volt 40k+ price tag and high maintenance cost any plans for rebate etc?
        • 5 Years Ago
        Well the rich hippy/techie crowd may go after it and it will come with an $8K tax rebate.
      • 5 Years Ago
      Yeah.
      The Volt concept car reminded me of the old Saab 9x concepts I used to lust over. The production Volt doesn't look as bad as I thought it would, but it is kinda bland...
      • 5 Years Ago
      Great article and I wish GM well but I think this car is nothing more than a novelty car for a very tiny consumer niche. First off, there is no infrastructure in place such as charging stations for any electric vehicle in any major city. Unless you live in a house with a secure garage for charging, you might have problems finding a way to charge the Volt at home. Its completely impractical for city dwellers who live in condos, apartments and the like - you can't charge it from the street. The limited range could be an issue for commuters and lets not forget the car's potential high maintenance costs from everyday wear. Then you also have the car's price, its high - again limiting to only those consumers who can afford it. I can see all those "going green" celebrities getting their hands on one but for regular people - the need for such a car is questionable.
        • 5 Years Ago
        Limited range? Huh? The range is only limited by the size of the gas tank. When the gas tank nears empty, go to a gas station.
      • 5 Years Ago
      Those A-pillars look ABSOLUTELY monstrous! In fact, just looking at the pics, I'd have to wonder how poor visibility is all-around in this vehicle.

      Very glad that GM seems to be doing all the right things, developmentally-speaking, though!
      • 5 Years Ago
      It AMAZES me how many idiots work for automakers and how many GENIUSES read Autoblog instead of working for the automakers. Never ceases to amaze me. Why, if GM just read the comments on here they'd probably produce the most incredible car EVER. They couldn't help it. It would just be world-changing. The things that we think about that never ever seem to cross the engineers minds! Buttons! Design! Just ask us! We KNOW!

      Why aren't they reading this stuff?! All their problems could be solved - Snap! - just like that.
        • 5 Years Ago
        ain't it the truth?
        • 5 Years Ago
        if only autoblog had a comment of the day...

        well played sir.
      • 5 Years Ago
      Now put the concept car body back on the thing and I'll get in line.
      • 5 Years Ago
      Looks like it will be a decent ride for those who want this kind of car.

      Personally I'd rather have a 2010 Corvette!
      • 5 Years Ago
      I think it's about time we saw it in a different color. Like that purple it was in on the transformers 2 set.
      • 5 Years Ago
      My question is, why is it only getting 42.2 MPG in that pic?
        • 5 Years Ago
        I know the 250 MPG or whatever was smoke and mirrors, but I was expecting something higher than the Prius at least.
        • 5 Years Ago
        "300 miles on 8 gallon tank = ~38mpg. "

        You forgot to run the batteries down to recharge territory. That's the entire point. The the mpg goes way up in a valid manner.

        Wake up everybody !!!!!!! (not just chad)
        • 5 Years Ago
        Why is this so hard to understand???

        The only time you get 38 mpg is when you drive 300 miles IN ONE TRIP!!

        When you drive 40 miles (like to work and back) you use 0 gallons of gas! That's WAY more than any Prius!! And every mile less than the max range, increases the mpg.

        And the cost of electricity to completely charge it in Michigan is about $0.90/day.
        • 5 Years Ago
        Not bad if that is the Gas only mpg. What were you expecting?

        http://www.insideline.com/chevrolet/volt/2011/2011-chevy-volt-eight-gallon-fuel-tank-assists-340-mpg-range.html

        300 miles on 8 gallon tank = ~38mpg.
      • 5 Years Ago
      Nice article. Looks like the Volt project is right on track.
      • 5 Years Ago
      So the ICE will never charge the battery above 30 percent of capacity? Interesting. What happens if you're taking a drive that's hilly, like through the Rockies, or I-75 through Kentucky? The ICE would be running a lot, and the battery could be frequently dipping below depletion, to handle hills that the ICE powering the traction motor couldn't manage. What if the generator couldn't bring the battery back to the depletion point? Would acceleration up hills begin to suffer?
        • 5 Years Ago
        i'm pretty sure the engineers are smart enough to not let this be an issue. in fact i'm not just pretty sure, i'm 100% certain. they tested it up pike's peak in range extended mode and it was fine.
        • 5 Years Ago
        I think those concerns are essentially non-issues.

        A 140hp gas engine will be plenty to power the car through any of the scenarios you mentioned. The ICE will still be running a lot if you were to take a trip through the Rockies or along I-75 in KY. I'd assume that either of those trips would be considerably longer than 40miles, once that 40miles is up, the ICE will be running regardless anyhow.

        Secondly, your comment(and many others) seem to think that 140hp is necesary to get any car moving, or at least it seems that way. That's not true at all. The times that this vehicle(or any vehicle really), needs its full power are very rare occasions. For example, take a drive up I-70 west of Denver into the mountains(I took that very drive yesterday in fact). There are some areas of considerable grade and elevation gain to be sure, but it's not like it's a constant 50mile hill. Even if it were, it doesn't mean you'd be using 100% of your engine's power to get up the hill all the time. What really happens is you cruise along at 65mph or so(that's the speed limit for most of that drive) and occasionally you'll be met with a steeper grade and you'll either dip into your reserve battery power to make it up the grade at your current speed or you'll slow down to reduce the load on the engine. Then a mile or so down the road when you reach the top of that higher grade, you'll go back to your cruise speed and the ICE will recharge the battery to the 30% level assuming you used anything below that level.

        Thirdly, torque is a very important part of the equation. I own a VW GTI with the 1.8T engine and in the numerous times I've driven up I-70 into the mountains(probably 20-30 times a year), I've been able to do so without having to shift out of 5th gear for the most part. I just set the cruise at 70mph and go. I never worry about overworking the engine and it keeps speed without issue even on the steepest highway grades and even loaded with 4 people, all our gear and a rack with 4 snowboards on top. The torque of the engine gets the job done. The Volt may be down on power a bit from my car, but it also has considerably more torque. Not to mention that it won't be affected by altitude like my ICE car is.
      • 5 Years Ago
      Interesting video about the development of the Volt:

      http://www.youtube.com/watch?v=SP-n7pmWX-k
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