Cranking the Volt to 100 M.P.G. - NYTimes.com

Cranking the Volt to 100 M.P.G. - NYTimes.com: "Because the Tesla never consumes petroleum while driving, the E.P.A.-required window sticker lists the energy consumed in kilowatt-hours of electricity. Translating the Roadster’s numbers — 32 kilowatt hours per 100 miles in town and 33 on the highway — to more familiar units using a textbook conversion factor yields impressive ratings of 105 m.p.g. in the city and 102 on the highway. But applying the adjustment factor devised by the Energy Department, which takes into account not only energy content but also such considerations as scarcity of the fuel and production and distribution efficiency, yields far more impressive mileage figures: 256 m.p.g. in the city and 249 on the highway."