Nickname for a powerful Chrysler V8 engine from the 1960s that had a hemispherical combustion chamber. The name has since been trademarked by Chrylser and applied to a new, 345 horsepower V8 that does not have the characteristic hemispherical heads. The new engine is not really a hemi; DaimlerBenz, the owners of Chrysler and Dodge, wanted a name that would convey the power of the new engine so they picked Hemi.
The copyrighted term Hemi and the accompanying engine have been marketed with a series of commercials featuring actor Jon Reep.
Q: That thing got a Hemi in it?
A: Well, if you mean, does it have the new, 345 horsepower Chrysler V8, then yes. But if you mean, does it have the legendary Mopar V8 characterized by hemispherical combustion chambers, then no, this thing does not have a Hemi in it.