Robert Paul Andrews wrote: > ...upgraded to 15" wheels...recalibrate the speedo You can go to any size wheel, and by changing the aspect ratio of the tire, get the same diameter, therfore no speedo recal, no change in gearing. section width (mm)/aspect ratio(dimensionless)-wheeldia(in) Therefore a 205/60-15 has a diameter of (205*0.60/25.4)+15+(205*0.60/25.4)inches Glenn