Yesterday GM shocked the automotive world by announcing that their upcoming electric-drive new Chevy car named Chevrolet Volt will gain an EPA city mileage rating of 230 mpg. It's an astounding claim - one that would make the new Chevy car more than four times as efficient as Toyota Prius. And yet, even the federal government says it can't back up GM's math.
The new Chevy car is one of several so-called Extended-Range Electric Vehicles, or EREVs, in development. An EREV functions as an electric car until its batteries are depleted to a certain level; then it starts a small gasoline engine. That engine, however, doesn't drive the wheels - it merely acts as a generator to recharge the batteries. Chevrolet Volt, GM says, can travel about 40 miles at any speed before its onboard generator kicks in.
That number is significant, because Department of Transportation figures show that most Americans drive less than 40 miles per day. For most of us, owning the new Chevy car could mean rarely ever using gasoline.