Dan, Right now I am running 16" front rims with 205/45 16's. The rear's are 17" rims wearing 245/45 17's. Working with Dan Deutsch and Luke at Tire Rack we found that this combination closely matches the stock wheel/tire combination diameters, thus no need for recalibration of the speedometer/odometer. Hope this helps, Matthew VIN #10365 VIN #16816