I see where you are coming from. I am in the same place, sort of. I want to be able to haul my samurai and my dad's tracker. I need at least 24' of trailer, but I really want 28'. The problem is that anything 28' long is way over built for what I am going to be towing. So we are going to build our own. As for the mileage thing every little bit helps and when you start getting taller the mileage falls off. For example when I towed my friends camaro to Dallas for him I got 14-14.5mpg, but towing my zuk on the same trailer I get 12.5-13 tops. The camaro is an easy 1000lbs more than my zuk but the zuk catches a ton of air.