Well, it's so hard to figure without knowing the kind of mileage their truck gets. I know lots of folks that might get 12 miles to the gallon, 10 if their hauling empty, as low as 5 or 6 if they are hauling loaded. I, personally, would never even own a truck that got such sh!tty mileage, but lots of people put up with exactly that.
Depends a lot on how much of the trip you can do at 'no load' highway cruising speed, too. When towing, our Dodge Ram w/Hemi MDS (that can run on 4 cylinders when possible) will easily vary from 17 mph to 10 mpg on the highway depending on how hilly it is. Posted via Mobile Device