The H2 (or whatever that giant incapable thing is) is definitely gas and a joke as an off-road vehicle. Basically it's a Tahoe or Suburban skinned to look sort of like a real military Hummer. More or less a toy for the uh, phallically inadequate.
Here's a couple H2's in action:
weak front end
and
stuck on a tiny tree stump
A real Hummer is a totally different vehicle.