Ford Deisel all the way. Mines a '93 no turbo on 35's and i get 13-15mpg. Dads stock 2000 gets 19-20. I bielieve that a heavier rig is always better when towing. Towing 2300 lbs with a rig that wieghs 7-8000 lbs is safer than with one that weighs 4-5000lbs. Ever see a toyota pulling a skiboat down the freeway and it starts whipping back and forth? Looks like the tail wagging the dog. What kind of milage do v-6 toyotas get nowadays anyway? My roomates 2000 only gets 10-12 but its lifted on 35's so id be curious to hear what the nonlifted ones get.
I dunno about that 35lbs per horsepower thing. My deisel is rated at 185 hp. it definatly outpulls my roomies 190 hp toyota, its not even a funny comparison.