Originally Posted by GregW / Oregon
I'm guessing 265F & 285R will be easily possible with the right offset wheels. You can even do that on the E46. Some ran 265 x 4 on the E46 to get rid of the inherent understeer. That is not as much of a problem with the E92, so a staggered setup should be fine.
I used to run 285/30-18 on my E46 front and back. Worked great though the front stuck out just a bit.
I would like to run a 9.5" rims for the front of the E92 and go to the same 285/30 setup for autocross use. If anyone finds info about front offsets before I do please post it.
As to the question about 11" rears. Yes it might cause understeer, but the car would still be faster with the extra traction. It would just need a different driving style.