Not sure why I got downvotes. I live in a shuttle bus with a similar running cost to an overland truck. Massive offroad tires are $500-1000+ each. The engines hold gallons of oil and changes cost over $100 for materials. They typically get 8-12mpg.

If you stay parked somewhere for a long period of time sure, your costs will be low. But in that case it doesn't matter what you're living in, maintenance costs will be roughly the same.