necro81 writes "General Motors, emerging from bankruptcy, today announced that its upcoming plug-in hybrid vehicle, the Volt, will have an EPA rating of 230 mpg for city driving (about 98 km/L). The unprecedented rating, the first in triple digits, is the result of a new (draft) methodology for calculating the 'gas' mileage for vehicles that operate primarily or extensively on electricity. The Volt, due out late next year, can drive approximately 40 miles on its Li-Ion battery pack, after which a gasoline engine kicks in to provide additional electricity to charge the battery. Running off the gasoline engine yields approximately 50 mpg. Of course, the devil's in the details, because the conversion of grid-based electricity to gasoline-mileage is imprecise." Now we know the meaning of the mysterious "230" viral marketing campaign.