"I'm as excited about the development of the Volt as I am about the vehicle itself," said Welburn, whose Volt design team has been working to make the plug-in electric more aerodynamic, thus increasing its range.

"In the old [GM] culture, you waited for the development of the technology to be used in the vehicle before you started designing it. In this case, the technology is developing as the vehicle is being designed."

Although there are still battery questions and other engineering problems to solve, GM expects its pedal-to-the-metal development approach to have the Volt in production sometime in 2010.

What will roll down those assembly lines is a dramatic departure from what the big automakers are doing now.

Unveiled as a concept car at the 2007 North American Auto Show in Detroit, the Volt compact is a pure electric, not a hybrid. In a hybrid, an electric motor and gas engine are employed singly or in concert to drive the vehicle's wheels. The Volt's wheels are driven only by an electric motor. The car's small on-board engine is used to drive a generator that recharges the batteries powering the electric motor.

The beauty of that engine/generator tandem is that it adds about 600 miles to the vehicle's battery-only range of about 40 miles. This solves the pure electric's ancient problem - limited range.

For many people, that battery-only range would be enough to meet their daily driving needs. They would simply plug their Volt into a 110-volt outlet overnight, drive to and from work or the mall, and then plug in again. They would have driven emission-free, and then refueled for pennies on the dollar compared with the cost of gas.

And if they have to drive more than 40 miles between charges, causing the engine/generator to kick in, that tiny engine will get better than 100 miles per gallon and cause little pollution.

Besides being cleaner and cheaper to run than any hybrid I can think of, the Volt is expected to be priced in a middle-class ballpark.

"It's a Chevy, so it has to be affordable," GM spokesman Mike Albano said.

The intense efforts to make the Volt more affordable and economical are particularly apparent in the efforts of the people working on its body design.

One of their chief goals has been reducing aerodynamic drag, which accounts for about 20 percent of the energy consumed by the average vehicle. In a conventional vehicle, better aerodynamics mean improved fuel mileage. In an electric such as the Volt, it translates into more miles per charge, hence more range.

Welburn said decreasing wind resistance was tougher with a compact such as the Volt than with a longer car, because it was harder to keep the air flow "attached" to the vehicle after it left the back of the compact's relatively short roof. And when it detaches, it causes counterproductive turbulence.

Working with aerodynamicists in GM's wind tunnel, designers were able to tweak the original Volt body enough to cause an approximate 30 percent reduction in its coefficient of drag. The result is something of a rarity: a car with a coefficient well under 0.30.

GM says those aerodynamic enhancements have added six miles to the Volt's battery-only highway range and three to its city distances.

If the Volt is a home run, it will mute the deserved criticism GM has received for scrapping its promising electric-car development program several years ago.

In fairness, we also might note that GM did not exactly contract amnesia when it called what amounted to a temporary halt to its electric-car development. The Volt will use a number of the innovations GM developed for its earlier, experimental electrics.

It is also true that GM has done its Volt development without the benefit of a $25 billion subsidy from the Japanese government, which is what Toyota reportedly got to develop its hybrid technology.

GM's Welburn chuckled when I mentioned this.

"You said it, I didn't," he noted.