Quote Originally Posted by H3_VX View Post
Only thing I want to be able to do is recalibrate for tire size.

With my oversize tires, I just use a more "analog" method-- the Discount Tire website "Tire Calculator". It will show your projected travel speed at various MPH settings.

http://www.discounttire.com/dtcs/infoTireMath.dos

For example, my oversize tires (275/65R18) run about 5 MPH above my actual speedometer reading. So if the posted speed limit sign says 60 MPH, then I just put my speedometer needle on 55 MPH with no worries.