GM says Volt will be rated at 230 miles per gallon

The Chevrolet Volt - the electric vehicle General Motors Co is counting on to recharge its image with consumers - is on track to hit an unprecedented fuel economy rating of 230 miles per gallon in city driving, the automaker said Tuesday.

GM Chief Executive Fritz Henderson said the Volt would get a "triple-digit" fuel economy rating for combined highway and city driving based on a draft standard developed by the U.S. Environmental Protection Agency.

"The Volt is becoming very real, very fast," Henderson said in an announcement at GM's technical center that was webcast to the public.

The Volt, which will be introduced late next year, is designed to run for 40 miles from a single charge of a lithium-ion battery pack. After the battery is partly depleted, a small engine will kick in to recharge the battery and power the vehicle.

In drafting standards to calculate the published mileage rating for the Volt and other upcoming electric vehicles, U.S. regulators have made assumptions about how much a typical driver will rely on the traditional gas engine.

Those standards, which will also provide a crucial benchmark under recently tightened federal fuel economy standards, are due to be published later this year.