Ole Buddy. I have a Ford F250 4X4 about same gas engine as you, yes it has tranny cooler and even tranny temp gauge. I pull a 18 ft bumper pull stock trailer, when loaded with four horses and or full load of hay, it pulls hard, makes the engive work and yes eats up gas. I also have same truck 99 F-150, same engine 4X4. The only differance is stopping...this is where you need to take heed...The F-250 has much bigger brakes than the 150. Yes I have electric brakes on the trailer but believe you me, if you need to stop fast the trailer will push the 150 all over the road where the 250 will hold its own much better. Good luck. Rich