Getting 255-40-17 on the appropriate 17x9s (they are pinched on an 8.5 - they are barely square on a 9") on the front of a stock fendered 1 series is possible but requires all the pieces to be perfect.
You need coilovers with short springs above the tire, camber plates (set at max negative camber, for sure more than 2.5 degrees negative), and a perfect offset wheel (for a 9", around +35). With those things, the 255s will fit perfectly. Adding the 1M arms will make it harder to clear and will have it rub under some circumstances.
I have gone through this exact process on my 128 and have tested the above thoroughly. Below is a photo of my car with 17x9 +35F, +50R with 255-40-17 RE71Rs WITH max camber plates and M arms. It rubs. Before the arms it was perfect, but the car is faster with the extra camber from the arms (-3.6 instead of -2.8) so I tolerated the rubbing.
-Mark
