Edmunds – 2011 Chevrolet Volt
Edmunds does a good job of explaining exactly what the Volt is:
“The Volt is a four-seat, four-door ‘series-parallel plug-in hybrid’ hatchback with a lithium-ion battery pack that can power the car’s 149-horsepower (111-kilowatt) electric motor by itself for an estimated 40 miles in the city. After that, the gasoline-powered inline-4 engine primarily supplies electricity to the motor for as many as 300 additional miles. All told, the Volt is the most advanced hybrid to date and quite possibly the most fuel-efficient car you will be able to buy.”
They note that there is no standard way to determine fuel-efficiency. If you never fully deplete the battery (by going a short distance at an easy clip and recharging the car every night) then you may never use any fuel. But over longer distances, you’ll use gas. Edmunds measured the fuel economy of the Volt with an empty battery and found it to be 31.4 mpg. In their long-term road test, they found the Volt varied between 47.9 and 111.5 in “apparent” MPG.