just got back from a small trip pulling a bumper hitch cattle trailer, three horses, the bed packed full of wood, hay and camping supplies. the trailer im guessing weighs about 2000 lbs the horses were around 1500 pounds each and i dont know about how much what was in the bed weighed plus three adults in the cab. Im impressed with my truck which is a 04 single cab stx with a 4.6 3.55 gears running on 33 inch tires. The mods that i have are intake, magnaflow exaust, edge evolution set on level 2, prodgy brake controler, firestone air bags i was running about 20 lbs of pressure. it was around 120 miles of highway, interstate and back roads with some pretty good hills. the hottest my transmission got on the edge was 170 on the return trip home. on the way to the camp site it managed to hit 160. Im glad i changed my tranny fluid with amsoil before i left the house. the amazing thing is that my truck didnt have the factory tow package. I had to buy my own trailer hitch and install it my self.