Wouldn't it be beneficial to tow an enclosed trailer with a truck with a cap or, even better, a van. If an enclosed trailer (for karts) is no taller than a van, then a van would get much better gas mileage than a truck, would it not?
I'm debating giving up my V10 truck to get a 5.4V8 Van. I'll be pulling about 1000 lbs less weight than the car/open trailer and the enclosed trailer should not drag nearly as bad with a van in front of it.
The theory is this: I get 13.4 highway with nothing behind the V10 truck, 10-11 towing highway. I'm thinking I should be able to get about 15mpg highway, 13 plus with the enclosed trailer (assuming the advantage of low drag). The guy with the van (a good friend) is checking his mileage loaded (2000lbs) and unloaded for me.