ya my numbers were to high for my rpm
im runnin a lil over 2500 at 70 i got 4.56 gears im pretty sure

1992 f250 non turbo 4x4.22.7 mpg on the highway not going over 65 mph.bad news is i get about 12 mpg in town driving.

i just changed my fuel filter and water separator filter, engine oil/filter, tranny oil/filter, transfer case oil, diffs oil, and rear greased all my nipples on the truck and serviced everything else as well and it went up from 14town/16highway to 17town and 20/highway... i have never seen blacker nor thicker oil in my whole life LOL...

i have a 1990 f250 non turbo with 491,000 kms and i get around 23 mpg US not imperial. doing no more than 100 km ( 60mph) on the highway.

when i have the truck loaded to about 11,000 lbs Gross combined weight i get around 14-15 on the highway. going about 90-100 kms.

My 90 with 4:10 gears and a 5speed gets about 17 riding around town. I got dual straight pipe exhaust and a "different" air intake.

fyi ... i took my 93 f450 dually PS 7.3 on a 400 mile round trip in one day thru the crazy mtn pass in BC Canada (i hate with a passion ( no other road to get there )... your either going up or down 6-8 % grades for long stretches towing a 16 ft tandem axles trail king trailer 14 gvw and got approx 15 mpg ...nopt bad considering the insane road i was one .... did i mention i hate that road ( eyes rolling) it handled it with ease .........

hope that helps

That route really does suck. We usually travel it once a year to Edmonton and back from vancouver.

Mine gets a solid 15 mpg. It's a 94 idi turbo, auto, 4x4, crew, flatbed, and stock size tires. Have no idea what the rear end is.