I watched as a really young kid, don't know the actors, post apocolyptic type maybe nuclear disaster? Focus on 3 or 4 characters, they drive a car type tank. They are looking for food and people? They find a starving boy child in what looks like a furnace or oven? They feed him lots of food but he dies because of it. Then I remember a scene where there is some sort of flood or tidal wave and it washes them away and when they get out of the vehicle there is a valley with green grass and horses eating. Some reason my brain says Kurt Russel is in this movie but I don't think so.

Sounds like Damnation Alley

Your right that's it... sorry about the time frame I just remember watching it as a 6 year old which would have put me in 1981. I guess it was Jan Michael Vincent rather than Kurt Russel. Thanks a million

You're welcome.

It was one of the high points of my young nerdling life when I once saw this movie's signature vehicle parked in a lot just off a highway in L.A.