no need, it's a +1. as long as you went from a 55 or 60 series profile to a 45 profile, the diameter is the same.Red99Stang said:Alright guys, here's the story...just got home from a tire store and updated to some 17 inch Cobra rims. SO..do I need to get my speedometer recalibrated or what? It seems fairly accurate while I'm driving..but any insight would be nice. Thank you!