Originally Posted by Used2be
Don't get me wrong, I also like the B18 rim, a very good looking one piece which I prefer to the bolt-together look. It does fit the style of the car, and I hope the after market will come up with some lighter than stock 19s that look as good. Even for track day use I'm not convinced that 20s will out perform 19s given the same tread width. Perhaps if I were such a good driver that the slight delay in response from the slightly more flexible sidewall made a difference, maybe, but since that isn't the case I'll go with the look I like.
I do think the 19s will outperform on the track for sure. For my purposes, I prefer the look of the 20s. I dont track and am more than satisfied with what the car can do with 20s. For the way I drive, I wouldnt notice the difference bewtween 19s and 20s. And as for three piece wheels, I have them now and in the past, they just dont hold up to these roads here. I also think Monoblocks suit the sportiness of the M5 better than three piece wheels with a lip.