Motor Trend is running a long term test on the volt. So far they have over 25k on it with no warranty issues.
They say in their article they are keeping meticulous records on it so far and this is the result.
The epa says the car gets 93 "empg" in electric.
MT is getting 103.4
The epa for gasoline driving is 37mpg.
MT is getting 38.7.
Looks like its living up to the specs so far. And no battery fires.