2011 Chevrolet Volt First Drive

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2011 Chevrolet Volt First Drive - Car News
We go for a spin in a prototype of GM’s Great Electric Hope.

BY TONY QUIROGA
April 2009


2011 Chevrolet Volt First Drive

Specifications

VEHICLE TYPE (Chevrolet Cruze–based prototype): front-engine, front-wheel-drive, 4-passenger, 4-door sedan

ESTIMATED BASE PRICE (NOVEMBER 2010): $40,000

ENGINE TYPE: 1.4-liter DOHC 16-valve inline-4, 100 hp (est), 90 lb-ft (est) (range-extending only); electric motor, 149 hp

TRANSMISSION: 1-speed direct drive

DIMENSIONS (Chevrolet Cruze–based prototype):
Wheelbase: 105.7 in Length: 178.5 in Width: 70.7 in Height: 58.2 in

PERFORMANCE (MFR’S EST)
Zero to 60 mph: 8.5 sec

Shell


A key component in General Motors’ attempt to survive and regain technological relevance is the 2011 Chevrolet Volt. Probably the only car in GM’s lineup that didn’t draw long sighs and eye rolls from a mistrustful U.S. Congress during recent hearings, the Volt is essentially an electric car that has the potential to outgreen current hybrids like the Toyota Prius and Honda Insight. But unlike the full electrics of the past, the Volt carries a gas-burning engine that automatically kicks in to provide juice once the onboard battery pack’s charge is depleted.

T-Shaped Battery Is the Heart of the Volt

We recently had the chance to drive the Volt—or at least an engineering mule of the Volt powertrain cloaked in the skin of a Chevrolet Cruze, the brand’s upcoming replacement for the compact Cobalt. This June, the Cruze mules will be retired, and for the first time, the Volt’s powertrain will be mated to the Volt body.

According to Tony Posawatz, the vehicle line director for the Volt, the Cruze-based mules represent 80-percent-correct versions of how the Volt powertrain will feel when it arrives in showrooms in November 2010. But GM wasn’t ready for us to fully experience the Volt; our drive was restricted to an electric-only experience, which is how the company imagines most customers will use the Volt.

“The beauty of the Volt is the size of the battery,” affirms Posawatz. Weighing in at 400 pounds, the lithium-ion pack allows the Volt to travel as far as 40 miles on electric power. The battery, made of about 400 waferlike cells, sits beneath the center tunnel of the car. It’s six feet long and branches out under the rear seats, forming a T shape. (Having a center tunnel in a front-drive car gives the Volt mule’s cabin the feel of one from a rear-wheel-drive vehicle.) Like most traditional electric cars, the Volt will recharge via a wall plug; the engine is simply to get you to your destination when the charge is depleted. A full charge via a 110-volt outlet is expected to take six to seven hours, and GM anticipates a two-to-three-hour charge time with the optional, Chevy-supplied 240-volt charging system.

Although the maximum total power output of the Chevrolet Volt battery pack is 16 kWh, the Volt only uses about 50 percent of the battery’s total power. By not charging the battery over 80 percent or discharging below 30 percent, GM hopes the pack will last 10 years or 150,000 miles in the car. After its life in the Volt, the battery will still be able to store about 12 kWh, and GM envisions that it could be used as an energy-storage device in a home once removed from the car.

First Impressions Are Promising

In the Volt, the battery feeds a 149-hp electric motor that drives the front wheels. The response and the immediate power are what we’ve come to expect from electric cars. The Volt is by no means a sports sedan, but it will briefly chirp its tires when pulling away from a stop. Acceleration is acceptable; with four occupants on board, the Volt felt like it could probably run from 0 to 60 mph in about 10 seconds. GM’s 0-to-60 target for the production Volt is a bit more aggressive, at 8.5 seconds. The single-gear transmission provides seamless and CVT-like acceleration from a stop. Unlike a gasoline engine mated to a CVT, the nearly silent electric motor doesn’t scream as it propels the car forward under hard acceleration. There is a bit of a whirring sound from the motor, but it is far from the spaceshiplike hum emitted by the electric motor in the Tesla roadster.

What isn’t yet clear is how the Volt will behave when the battery is depleted and the gasoline engine kicks in to provide more juice. In this so-called range-extending mode, the electric motor will be limited to the power provided by the 1.4-liter four-cylinder engine under the hood. The gas engine is never used to charge the battery; the engine turns a generator that directly feeds power to the electric motor. If the engine is revving at 2000 rpm and making 25 hp, the electric motor will be able to make only 25 hp. If more power is needed, the gasoline engine could conceivably run at its power peak at a very high rpm. Taking the point further, if the gas engine is rated for only 100 hp (our estimate of its power output), the 149-hp electric motor will be able to make only 100 hp. The upshot: The Volt will be quicker running on battery power than it will be when the gas engine is providing the electricity.

Unable to try the gas-fired solution for ourselves, we asked Posawatz how the experience will change when the battery is discharged and the gas engine comes on. “The work being done by the development guys as we speak is to create a gentle feathering of engine rpm,” he said. “So you don’t even notice that the engine kicks in. And to try to operate at the right points and to transition the rpm points depending on the load you’re getting—to behave like someone would want it to behave. You may get into a position under an extreme grade or hill climb where the engine rpm will be pretty loud—running pretty hard. At a certain point in time that rpm will be relatively unpleasant. This is the challenge of different road loads: How can we keep the NVH reasonable for a customer?”

Judging by our drive, the Volt will work quite well as an electric car. But without getting the chance to drive it with the gas engine switched on, we wonder how the experience will change once the battery’s charge is depleted. GM imagines most Volt buyers will rarely operate in the range-extending mode and will instead primarily run the car on battery power by plugging it in as often as possible and driving fewer than 40 miles at a time. To those folks we can say that the future will feel surprisingly conventional, if eerily quiet.


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