Driving the Chevy Volt isn't special, and that's good

We've had our first taste of the drive system under development for General Motors' pioneering Chevrolet Volt, piloting a test mule based on the Chevrolet Cruze at the company's Warren (Mich.) Technical Center, and it left us hungering for more. Yes, it's an electric car, but mostly, it's a car--one you could imagine driving every day without feeling as if you were engaged in a lab experiment.

Frank Weber, vehicle line executive for the Volt, gets his nose out of joint if you call the drive system a hybrid. True, it has both an electric motor and a gasoline engine, but the system--dubbed Voltec--should more correctly be called an extended-range electric vehicle, because it operates all the time in pure electric mode. The gasoline engine never drives the car; it kicks in only after the charge in the lithium-ion battery pack is depleted. The engine then runs a generator that maintains the charge level.

From an operational standpoint, this is "extended-range" mode, but the engineers prefer to call it "charge-sustaining," not least because their engine isn't going to run hard enough to restore the charge to 100 percent. Instead, it will generate just enough to keep the state of charge at or just above its minimum while the car continues to run purely on electricity until the driver can plug it into the grid for a recharge. This not only minimizes the use of gasoline but also takes out some of the complication inherent in the charging system.

In fact, our first behind-the-wheel experience with the system was in a car with its gasoline engine and charging system disabled. We didn't get anywhere near the vehicle's intended 40-mile range limit--confined as we were to the Tech Center campus--so we can't really tell you what it's like in extended-range mode.

There was room enough to make a few sprints to 62 mph (100 km/h on the mule's metric speedometer) and get a taste of how the car would perform in regular use. GM says it should hit 60 mph in less than nine seconds, and that felt about right. The car was still accelerating strongly as it approached the speed where you'd be looking to merge onto an interstate.

Except for being extremely quiet, lacking even the motor and gear whine that characterized our other experiences with electric cars, the most notable distinction was that driving the vehicle was utterly ordinary. We noticed, too, the lack of interruptions for gearshifting, smoother even than the liquid progress found in the latest luxury cars with seven- and eight-speed automatics. We were left thinking that GM should be rushing Voltec into its luxury brands.

Integration of the regenerative braking with the regular hydraulic system is good, and Weber promises that it will get better still. It's better than what you get in most hybrids today. There are two selections available via the transmission lever. In normal drive mode, the car coasts when you lift off the accelerator pedal; in low mode, it goes into regenerative braking as soon as you lift off. Old-school car guy Bob Lutz referred to it as "engine braking." It would be useful in city traffic or spirited driving on a twisty road but is too aggressive for highway use.

The supposedly crude mule we drove is one of 35 being retired soon, to be replaced with "production-intent" prototypes using the Volt bodywork and interior. We saw stacks of battery packs ready to go into those cars, which we look forward to driving in the fall.

By Kevin A. Wilson