Introduced at the North American International Auto Show here, the Chevrolet Volt will draw power exclusively from a next-generation battery pack recharged by a small onboard engine -- if the technology is ready in two or three years.

"We have a thoroughly studied concept, but further battery development will define the critical path to start of production," said Jon Lauckner, a GM vice president for product development.

The Volt is designed to run for 40 miles on pure electric power, making it marketable for everyday family use.

For the average American driver who drives 40 miles a day, or 15,000 miles a year, the Volt will require no fuel and lead to an annual savings of 500 gallons of gasoline, GM said.

Unlike current gas-electric hybrids, which use a parallel system twinning battery power and a combustion engine, the Volt will be driven entirely by electric power.

GM has been stung by criticism that it conspired to kill the EV1, an experimental electric vehicle program it launched in 1996 and killed by 2003. The documentary film "Who Killed the Electric Car?" released last year criticized GM for first developing but then abandoning electric vehicles.

GM said the Volt will have advantages over the defunct EV1, including smaller batteries, faster recharging, more room for passengers, and a faster maximum highway speed.

"For most drivers, the Volt will use little or no gasoline," GM chief engineer Nick Zielinski told reporters.