230 mpg claim for GM Volt is not believable

GM's claim that their new Volt can get 230 mpg is incredible. By that, I mean not believable.

The EPA has always rated fuel economy for cars that plug into the grid based on the energy equivalent of the electricity they use. For example, the 2001 Toyota Toyota RAV4 EV was rated at 104 mpg.

GM says that in all-electric mode the Volt will go 100 miles on 25 kilowatt-hours. Under longstanding EPA rules, that amounts to only 140 mpg. And all-electric mode is the most efficient scenario possible for this car that can run on both grid power and gasoline. The only way GM could claim 230mpg is if they are only counting the gasoline used and not the electricity.

That makes the 230 mpg claim a lie, and GM should know better.