[newbmwowner1]

I am a new owner of a 2011 328xi wagon. When I bought it, the dealership offered to help out with tires (the rear ones were shot) so I had them replace the stock runflats with Michelin all-seasons (can't stand runflats). I've been driving it for about a month with runflats on the front and the all seasons on the back, figuring I'd swap out the run flats when they ran out of tread. However, I just read online that using different manufacturer tires on an AWD system can be really bad for the transmission. Can anyone validate that for me? How serious is it? The runflats have like 80% tread so I'd hate to swap them out early, but I would obviously do that over risking grenading my transmission. Just not sure how important this is. Thanks!

[chatch10]

From what I understand as long as the tires are within 1% rolling diameter of each other then you are fine and it won't mess up the AWD system.

My biggest concern would be traction as you have two different sets of tires that will handle differently. I would swap out the front run flats to match the rears and maybe you can sell the run flats to make up some of the cost.

[John 070]

This is what I've always heard....staggered tires introduce understeer, but not on a vehicle that came with them, that is for traction. Can anyone explain? So if my 335i had ZSP, and another one did not order it, and they stagger the tires, do they introduce understeer? My guess is no. But say you take a car that is always square, and you stagger, then yes?