Wheel-Tire size comparer
Wheel-Tire size comparer - RIMS-N-TIRES
This is an awesome site to compare how different wheel and tire sizes will affect fitment and the speedometer on your car. The image above shows the difference between the stock BBS wheels that come with the 2006 STI and the new WedsSport Weds TC105N that I have on order. The link to the actual data is here.