Originally Posted by Tinker
that's interesting. The German site (www.michelin.de
) didn't have that size available anymore. Both sites also show the attached list of available dimensions for the Michelin Pilot Sport which is missing the relevant size for the rear axle.
I just received an answer from Alpina. They tell me I could also use the following dimensions :
Front: 225/45 ZR17
Rear: 245/40 ZR17
Does anyone run these dimensions on a B8? How will the car handle with these tyres? The rear tyres will have a circumference which is approx. 3 cm bigger than the original dimension. I've taken of 4% from the circumference since it seems to be common practise (see also www.m-forum.com
) when calculating the speed.
265/35 - 18: 1.86 m
245/40 - 17: 1.89 m
255/35 - 18: 1.92 m
265/35 - 18: 1.94 m (not sure, if this would fit)
Mill, if I remember correctly, you run yours on 255/35 - 18. They are even bigger than the 245/40 but you also have the shorter rear-axle (2.93 vs. 2.79) which slightly over-compensates for the bigger tyres.
If my math isn't all wrong, this would be the speeds at 6000 RPM in sixth gear (the gear ratio is 1:0.828 I belief)
Tyres 2,79 2,93 3,15
265/35 - 17 290,1 276,3 257,0
245/40 - 17 295,1 281,0 261,3
255/35 - 18 298,8 284,5 264,6
265/35 - 18 302,1 287,6 267,5
Are most of you still running the stock size or have some of you switched to other dimensions ?