On Tue. Mar 24 I'm going to attempt to put some Bridgestone Potenza 275/35/18's on the rear of my 2009 328i. I know the 09 M3's have an option of 265/35/19's but their wheel wells, I'm relatively certain, are more flared. If you go tire rack, pick your tire and then go into the specification page for that tire you will see numerous numbers, sizes, diameters, tread width, section width, required wheel width. Compare those numbers to your existing tires and then start looking at your car. The biggest place to look, in my opinion, is the front wheel well with the wheel fully turned, i.e. turn wheel full left and check the back of the tire in relationship to the back of the left wheel well. This is guessing at it's best but you can go over sized quite a bit if you do some studying.
Last edited by Skywagon; 03-21-2009 at 05:52 PM.