:The civilian " Hummer H1 " started out as a variation of the same basic vehicle as the military HMMWV-but those vehicles are very wide-almost impossible to park, brutally uncomfortable, uncrashworthy, hideously expensive to fuel and maintain, etc . So for the last 10 or so years, Hummers H2's and H3's have been nothing much more than an alternative body shell bolted onto a standard GM SUV chassis & engine ( I kinda recall it was a Chevvy Tahoe ).
