I used to do rust repair at my welding shop (now retired). I have seen other makes of suvs and trucks that were less then 10 years old the had unrepairable frames, and a large number of those were not plow trucks.

The manufacturers have really stepped up the planned obsolescence and they have figured out making poorly designed under carriages is the fastest way to sell new trucks. when the bottom rots out, no one can use them. To their advantage, they get to blame the road salt and other chemicals used to clear the roads.

I wouldn't buy any used truck without climbing under it with a pick hammer and hitting questionably spots. If the pick hammer blows through, that section is gone. Pick until you find something solid, and see if a patch can be welded in. If a patch can not be easily welded in, walk away from the truck.

In the next 10 years, all those fancy electrical components going bad will be the next vehicle killer. Gene