[K8_M235i]

I run 245/40r18 square as well. My wheels are 18x8.5+40, but I need at least a 5mm spacer on the front to clear the strut.

I am RWD. I wonder if there is a small difference with the strut/knuckle with xdrive that pushes the wheel further away from the strut.

I run a 10mm spacer front because I'm running -2.5* front and rear camber. I also run a set of 17x9 +42 with a 10mm spacer front and 255/40r17.