[XC3LLR8]

I've ordered the ZTK package (performance wheels, etc.) which includes 8.5" and 9.5" wheels. I've always preferred a more meaty tire over anorexic sidewalls in both looks and protection, while knowing you may give up a little in razor-sharp turn-in. With this in mind I've started looking at Michelin Pilot Sport 4S's in plus sizes, while staying within specs of Tire Rack's Rim Width Range.

I couldn't figure out why a 275 would have a more narrow Tread Width than a 255, so I started an online chat with Tire Rack. Turns out BMW will establish tire specs for specific models, and in this case the 275's Tread Width is for new M3's and M4's. I'm guessing when you have a tread width that is significantly more narrow than the rim width it makes initial turn-in feel much more responsive, and this is the effect BMW is going for?

Moral of the story: If you want a tire with more tread, and appears wider, make sure you compare the other same size / same brand options to the ones spec'd for BMW.

When it's time for new tires I'm considering 255/35 for the front, and 275/35 for the rear. Quality spacers will be used for final fitment perfection, just as they will with the OEM tires.