General Motors said Tuesday that its Chevrolet Volt with its rechargeable battery is expected to get at least 230 miles a gallon in city driving. The car is scheduled to be released in 2011.

G.M. said the number was based on developmental tests using a draft federal fuel economy methodology for plug-in electric vehicles.

The Volt uses a battery pack and is powered by an electric motor with a 40-mile range, and the calculation essentially assumes that most drivers using the car to commute will stay within that range and will not need the car’s gasoline-powered generator to produce electricity. The majority of time, drivers in the city will be in an electric mode, the company said during its presentation.

“Most Volt drivers will operate on a daily basis without having to use a drop of gas,” G.M.’s chief executive, Fritz Henderson, said. He said he was also confident that highway mileage would be “triple-digit.”

http://www.nytimes.com/2009/08/12/business...