I have an 86 E-150 with a 4speed on the floor.... it's going to be a basket better than the 460 auto E350 I've been driving. I got it so I can travel (mostly highway) and keep it affordable, and the different estimates on the different sites all give different city and hwy mpg esitmates...

What could I expect with an empty 1/2 ton with a 300 6cyl and 4spd on the highway, and is there anything I can do to improve that? It has a factory 1bbl carb on it too by the way... thanks!

 

At speeds less than 62 mph [very important when you are pushing a "brick" through the air] would be 18 - 24 mpg, if your original computer controlled feedback system is still functioning as designed.

Keep engine in tune, tires properly inflated, carry no excess weight, check alignment, make sure brakes are not dragging, do not have a roof mounted cargo carrier, use the A/C, 194F thermostat and possibly synthetic lubricants.

Shift into the next higher gear as soon as possible without lugging the engine and accelerate like an old man [pretend there is an egg between you foot and the accelerator pedal].

I had an 1984 F150 [4.9L] with 2.47 rear gears and 4 speed manual O.D. It was a real dog on acceleration, but could return 26+ mpg @ 60 mph.

 

https://www.ford-trucks.com/forums/3...nline-6-a.html

8 Pages of MPG stuff there. The subject has been pulverized.