like what Harte 3, if you drive 75 your mileage will suffer even if you change trannys or gear ratio. Wind resistance at 75 mhp is more than double the resistance at 50 mph. This is a big deal in a aero brick like a 93 F-150.
1995 F-150, 300-6, 4x4, ex-cab, sb, 3.08 5-speed, 2 1/2 in. exhaust w/flowmaster 50, MSD + ignition upgrades, canopy, 171,000 + miles Gone but not forgotten: 1965 F-100 240 3spd lwb "the green hornet"; 1991 f-150 300 5sp 2wd sb, 1960 F-250 4x4, 223 six, 4sp with wrap-around rear window, two-tone paint.
Tow vehicle: 2012 F-250 4x4 6.7 diesel XLT s/c lwb 20+mpg