This confuses the snot out of me. I get 15-16mpg pulling my boat with a 3/4 ton pickup. I get about the same mileage pulling a 7x16 enclosed trailer that empty weighs twice as much as my boat + trailer. I think there is a lot more windage there then you would think. The absolute worst mileage I've gotten was 7mpg doing 70 through Illinois into a headwind way over weight, (like pickup and a 24' enclosed car trailer packed full of crap were close to 27,000 lbs), it confuses me why something so small like a beach cat would drag my mileage down so far. Heck, I put 7 boats in that same car trailer going out to the mini-mega in NY last year and averaged 12.7mpg! I get around 20mpg empty btw.

or, the air comes off the back of my pickup in the least cat-towing-friendly way possible.