Originally Posted by RunFat
Thanks for all that useful info. I'm going to get the rear fender rolled, so I'm considering ARC-8 with these specs: 18x8.5" et38 front, 18x9.5" et35 rear.
Q1: With 235/40/18 up front and 255/35/18 in rear, the tire diameter difference is 1.472%. Is that under acceptable limit? 225/40/18 would be almost identical to rear in diameter, but do you not recommend that because it might be stretched up front? If I wanted to do PSS which measure ~ 10mm wider than most tires, would you still suggest 235/40/18 or would you recommend 225/40/18? I was thinking 8.5" et38 ARC-8 with 225/40 PSS and 9.5" et35 ARC-8 with 255/35 PSS would look noticeably wider and more aggressive than my stock. What do you think? And thanks AGAIN.
Q2: Going from stock 8" to ARC-8 8.5" wheel up front gives "10mm LESS clearance on the strut side, and the outside edge of the wheel will EXTEND an extra 2mm". Since you recommend 8.5" up front I assume I have sufficient space on strut side to give up additional 10mm? Can you comment on that?
The 1.472% difference in diameter is acceptable, but the 225/40/18 can also be used if you would prefer a similar overall diameter. We usually recommend the widest tires that is able to fit on a car with the particular wheel size and offset, and the 235/40/18 happens to be the widest tire that would fit on the front of your e90 LCI. The 225/40/18 will be a little bit stretched, but if you are okay with not getting the widest tire on the front, it can work.
Yes, there is sufficient space on the strut side to fit the 18x8.5" ET38 ARC-8 wheel on your e90 LCI. There is adequate clearance from the wheels and tires to the OEM struts of your car.