I think a fully prepped for mpg F100 would be hard pressed to get close to 30, but it seems to me 25 should be quite easy.

You just have to do everything possable, and not skip out. Intake, exhaust, electric fans, under pulleys, tuning, keeping the truck clean, and a tonneau cover. Then you can add roller rockers, and taller thinish tires on lighter weight rims "with-in safety limits" to finish up if you wanna go the last inch.


I've gotten 22 hwy out of my 07 gmc, and its bigger in every conceivable way then my 66 F100.

Also a guy I knew was getting 24+ hwy out of a 77 chevy with a 4.8 4l60 transplant. It wasn't fully tuned yet when I knew him. So its hard to say how much would of been left in it if any at all. It was tuned to get running and lose the codes at that point, and not for anything else.

Diesel is a game I don't understand, but car-crafter was getting over 30 with with his. Plus alot of performance parts, and rims not really that good for mpgs. I would be interested in building a diesel mpg miser if I ever get a chance.