Is there a formula I can use to calculate the optimum rim width for a tire size? I'm ultimately trying to figure out if I should use an 8" or 7" rim for a 255/60/15 tire. Thanks in advance. -- Bill M 65 Coronet 500 'vert http://1962to1965mopar.ornocar.com/mmo62008.html 73 Dart Sport. 21 Model T Depot Hack