What's behind the speedometer Error, and tires... Confused about it... How does it work?
Is this the same thing with rims?

 

If the overall diameter of your tires is larger than your factory tires was, then your car will be traveling faster than indicated by the speedometer. Opposite is true if new tires are smaller than factory, you will be traveling slower than indicated by the speedometer.

Has nothing to do with the wheel diameter, only the diameter of the tires...