The 2012 Ford F250 XLT 4X4 Crew Cab bolt pattern is 8-170 mm. This means there are 8 lugs and the diameter of the circle that the lugs make up measures 170 mm or 6.69 inches across. To get a close measurement of your 8 lug bolt pattern without a bolt pattern tool you should measure from the center of one lug to the center of the lug across from it.
