My dad bought an '88 F-150 Supercab 2wd Shortbed with a 300 I6 and 5spd in 1990. The truck never got higher than 15mpg empty, and got around 9mpg pulling a 14' camper. He drove that truck for many years and it was certainly capable of doing anything. It ran perfect and was one of the cleanest '88 Fords trucks I've ever seen.

He sold that truck in '02 or so because he bought some property and needed a bigger truck to haul the tractor and trailer around. He bought an '89 F-250 Supercab 2wd Longbed with a 460 and C6 Automatic. That truck never got higher than 12mpg, and pulling the same camper on the same trip it averaged 9mpg. Pulling the Ford 9N on the 18' trailer it also got 9mpg, even with double the weight behind it. Again, a great truck with plenty of power, super clean, and well taken care of.

I drove both trucks several times, around town, long trips, etc. The 300 truck was comfortable and would get out of it's way easily, but the 460 would just plain scoot. When pulling the 18' trailer with my RX-7 Turbo II on it to the dragstrip 120 miles away with the 300-powered truck, I could really feel the trailer behind me. It was a slow ride up to 65mph, and going uphill required downshifting and slowing to 50mph. Pulling the same car on the same trailer, on the same trip to the same track behind the 460 truck, I didn't know the trailer was behind me. Getting to 70mph felt as if there were no trailer, and going up hill the engine pumped out enough torque that I didn't have to slow down at all.

That's my personal experience. The 300 I6 is a great engine when backed with a 5spd in the right sized truck and is a very respected engine. The 460 is a powerhouse, plain and simple. This really is comparing apples to oranges.