Although I had 235/40/18 on my B5 S4. I found that the tire was just a little noisy. But if I parked it for a few days it seemed to flat spot itself, giving me a thumping sound for a few minutes until it warmed up. On my wife's 04 A8L, she has 275/35/20 Michelin P/S A/S. Very stable tire with a good ride. I've never been a big fan of Michelin but that's all they had from Tirerack in that size for a A/S tire. I just put the Michelin PS2 on the S4 (255/35/18) and it is buttery smooth and quiet.