How GM's E-Flex Propulsion System Works

E-Flex and the Environment

GM wants the E-Flex platform to be an environmentally friendly one in terms of emissions and fuel economy. They're on the right track so far: E-Flex-powered cars produce no emissions whatsoever for the first 40 miles (64 kilometers) driven. While the car's running on battery power, the electric motor puts out none of the chemicals and air pollutants for which gasoline-powered cars have been so maligned.

Once the internal combustion engine kicks in, GM engineers estimate that drivers will get about 50 miles per gallon (21 kilometers/liter) with the range extender. The Chevy Volt concept car touted an overall range of more than 600 miles (966 kilometers), but the production version has a range of about 360 miles (579 kilometers) due to a reduced gas tank size. GM engineers simply decided the extra tank space and additional weight weren't necessary.

GM officials insist that the change makes sense. "Since people almost never drive over 400 miles without stopping, why carry all that extra fuel around that you may never use?" Darovitz asked. In fact, most people may not ever use gasoline, since GM estimates that more than 75 percent of U.S. commuters drive less than 40 miles (64 kilometers) a day [source: Chevrolet].

If all goes according to plan with the E-Flex vehicles, those drivers will never use a drop of gasoline or produce any harmful emissions during their daily commutes -- although the reduced size of gas tank may ironically boost the vehicles' fuel economy. But just in case these drivers decide to test their new powertrains and hit the open road, the cars still get about 50 miles per gallon (21 kilometers/liter).

So, when can you buy the Chevy Volt and for how much? What else can drivers find on the E-Flex platform? Find out on the next page.