Originally Posted by bmw335iguy
To add to my first comment, I have a 135i with Forgestar F14's that have the same specs as your ARC 8s and I run Michelin PSS size 235/40/18 and 265/35/18.
Slight rubbing in front even after 2 sessions of fender rolling, and slight rubbing rear inner wheelarch lining from the extra wheel height when rear suspension travel is near to maxed out. Stock M-spec suspension. I trimmed the parker (that holds the lining from the inside) to prevent punctures, not too concerned about the cloth lining.
For my next set of PSS I will probably go with 225/40/18 for my front tires to stop the rubbing there. "