The movie was Damnation Alley and the vehicle was the Landmaster. Both have wikipedia pages.
I built a stair climber platform based on those wheels in high school. Very cool! The other show is linked from the landmaster page "Ark II".
Damn you now I need to watch them again

they bring back good memories of making mom crazy!
Enjoy
http://en.wikipedia.org/wiki/LandmasterThe Landmaster vehicle, features a hinged center section, and a unique rotating 12-wheel assembly. The "Landmaster" was custom-built for
the film at a cost of $350,000 in 1976. [4] ($1.4
million in 2010 dollars) [5]
The Landmaster should not be confused with the superficially similar but simpler Ark II.