In an official announcement today GM revealed that the EPA mileage figures for the Chevrolet Volt will be over 230  MPG city,  with a combined city/highway average of 100 MPG .  According to GM, these numbers are based on developmental tests using a new federal fuel economy methodology for plug-in electric vehicles which measures kilowatt hours per 100 miles traveled, calculates the petroleum equivalent of electricity, then takes into account the predicted degree of gas operation.  In the case of the Volt, it assumes that most of the miles driven will fall within the cars all-electric range of 40 miles.  GM expects the Volt to consume as little as 25 kilowatt hours per 100 miles in city driving, which at averaged (current) U.S. energy prices works out to a minuscule 3 cents per mile.

GM has been quietly paving the way for today's rather astonishing announcement  with a cryptic add campaign via T.V. and Internet which shows only the number 230 (with a happy-face electrical outlet replacing the -0-) and today's date.  If, as some auto industry experts believe,  mileage numbers are becoming the new horsepower in terms of marketing, Volt sales might be expected to get a tremendous boost  from these numbers. From the way that this information has been promoted thus far, it appears that GM is ready to capitalize on this possibility.  Chief executive officer Fritz Henderson was quoted as saying "... a vehicle like the Volt that achieves a composite triple-digit fuel economy is a game-changer.”

Mr. Henderson later noted "The key to high-mileage performance is for a Volt driver to plug into the electric grid at least once each day.”  The photo above is the first ever of the Volt's home charger.

Specific numbers for gasoline mileage while in "range extend" mode (with the on-board gasoline engine driving a generator to power the vehicle) have not been released by GM.   According to Frank Weber, global vehicle line executive for the Volt, “Actual testing with production vehicles will occur next year closer to vehicle launch."