Originally Posted by demosthenes
When my run-flats are close to worn out, I'm going to replace them with Michelin PS2's and carry a compact or full size spare in my trunk. My brother has PS2's on his E46 and he loves them.
The run-flats are fine on nice roads, but they can get harsh on rough roads, even with my 17's. The 18's are probably a bit rougher.
Actually the 18's are a bit softer than the 17's. The reason being there is less of a side wall. The 17 have more of a side wall and that makes them stiffer. When I ran 17's on my 325xi everytime I hit a bump or pothole I felt liek the car was going to fall apart. Everything was shaking so badly. However when I picked up my 335xi cpe I had the 18's with rfts and the ride was softer due to there being less side wall and being less stiff. But I took them off anyway and put on yokohama advan S.4 all seasons anyway