No brake on green speed

It was enough to make pit crews sweat. Cars racing on an auto-cross course at Maryland's Mason-Dixon Dragway and not once needing their gas tanks filled.

Purveyors of earplugs were uneasy, too. The track was eerily quiet.

Last Sunday, the cars racing were all electric -- no roaring engines. No exhaust fumes.

There's a big difference between watching a crew scrambling to refuel a car mid-race and watching someone plug the car up to an electrical outlet. It's the difference between watching professional wrestling and watching croquet.

But Plug-in-America, a non-profit organization that promotes electric cars, keeps plugging along on its mission to promote electric cars and touting their eco-friendly features. This was the ninth year for the electric car race, and each year, the entries get better.

The winner was a sleek, dark red Tesla Roadster, clocking in at 103.9 miles per hour. The $109,000 Roadster is powered by a special lithium battery that can cost up to $30,000.

But think of all the driver saves on fuel and earplugs.