I replaced my 86 F150 with a 302 in 2 wheel drive, it was a great truck., with a 94 4x4 F250 with a 460. Never looked back and still have that truck. In 02 I bought a 4x4 GMC 2500 with a 496, leaps and bounds of power over the 460. 460 being top dog when I bought it. The 460 is actually more fuel efficient pulling a trailer over the 496. But the 496 is like driving a 60s muscle car. In 05 after Katrina gas was @ $3.50 a gallon so I bought a 05 Dodge 2500 4x4 with a Cummins. Big truck capability with small truck fuel mileage. Had that truck all over the continent. If you drive a lot, that's where a diesel shines. And pulling is what it does best. I have gotten in the 20s pulling a trailer with it. But staying in your budget is going to be tough in this market. I'd hate to have to look for a vehicle right now. And fuel efficiency isn't going to be the same as with the fuels of old.