Chevrolet has claimed that after testing pre-production versions of the Volt 'extended range' electric car it's set to post over 100mpg as its official combined fuel economy figure, and 230mpg in the city. Put that in your Duracell and smoke it, Prius.

General Motors is making the claims tentatively because the tests that generated the numbers aren't official yet, but they should be shortly when the US Environmental Protection Agency (best known here for the dastardly scheme that saw Springfield encased in a glass dome in The Simpsons movie) rubber stamp them as a standardised way of labelling electric cars in America.

Converted to UK mpg it means the Chevy Volt - which is due in America in late 2010, though more likely to be early 2011 - is capable of an almost silly 276mpg in the city. However, that's assuming the driver charges his Volt at an external fuel source every day, does a sensible amount of daily mileage, and drives alone with minimal air conditioning use. European tests will no doubt be different to those agreed in America too.

If you've not been listening, the Volt is driven by electricity alone, but carries an onboard petrol engine that acts as a generator and kicks in when the battery runs low and charges it on the go. It means the Volt will be capable of around 300 miles between charges (and fuel stops), but that those doing short commutes need never tap into its fuel reserves in theory.