Why are you so excited about 38" tires? Why not get a truck with 48" tires...........or a truck with 60" tires?

None of them make much sense and all can be considered ridiculous when fuel is $4.00............so, if you're going to be ridiculous, you might as well get the largest tires that you can find.

Personally, I don't understand what the attraction might be.............if you want the height, just buy a 10 wheel tractor and drive it around without the trailer. Probably get about the same fuel economy..........maybe 10 mpg.