Ram towing mileage

Just this past weekend towed my car trailer, with my buddys AMC on it to the drags.
6.4 4.10 gears 4wd, 8 mpg but that was up and down WVa hills with the cruise control set at the speed limit.
Not bad since it only gets 10 mpg empty.

Now I do have a small enclosed trailer 5x8 that I tow behind my Wrangler, and it will get over 20 mpg towing, the jeep is a 4 cyl turbo.