Since I bought tons f250/f350s so I doing list trucks that was good.
1987 f250 reg
6.9L V8 diesel IDI NONTURBO
T18 4 speed
Unknown could be 157 or 257 or 357K miles
Best Fuel Economy Empty:
23 mpg but it alway load with tools. 1000 pound Speed were 60 mph
Best Fuel Economy Loaded (truck plus dump trailer/ 5k pound concrete) Estimated 13,500 pound
Load / Driving: 13 mpg
1999 F250 reg
auto 4R100 it slipping
Empty it about 5400 pound. Best mileage down highway 60 mph. 17 mpg.
On speed limiter it got 16 mpg with 1200 pound of brick in bed.
Best Fuel Economy Loaded (truck plus trailer/ 9,700 lb F350 dually box) 16,700 pound at scrap weight scale. It got 5 mpg rpm were 3500 most time.