whats going on fellas...sold my dad my truck...its a 2000 f150 4x4 4.2 v6 with 285/75/16 buckshots..107,000 miles....could someone tell me how to calculate the mileage..cause it wont calibrate to that size of a tire...want to know wat kinda mileage he gets, comes factory it says with 235 but that would look terrible..had 255 when i bought it in 2003...i reckon total mileage on the tank with the 285s is around 275 or less....love to know fellas...preciate it...