Originally Posted by schwank

I have the 18" factory option turbo twist rims on my S. I just ordered a new set of Bridgestone 960AS Pole Positions from TireRack in the following sizes:

F: 225/40-18
R: 265/35-18

As you can see the sidewall height number drops down when using a wider tire. But if you do the math, the sidewalls are less than 3mm variance since that number is actually a ratio.

Hope that helps!