I am getting ADR M-Sports in the mail hopefully the end of this week or the around of next week. The fronts are 18" tall by 8.5" wide and the rears are 18" tall by 9.5" wide. The front currently has Kuhmo MX 245-40-18 and the rears currently have Kumho MX 275-35-18. I was wondering what is the max tire size that I can fit safely on the front 8.5" and the max tire size that I can fit safely on the rear 9.5". What offset do you think would be best for each? Thanx in advance guys.

 

I would stick with the 245/40 and go with a 275/40 rear. Thats the common setup around here. There is a thread at the top of the wheels/tires... section that has acceptable tire sizes for different size wheels.

I have 9" fronts with 245 and 10.5" rears with 275, so you should be fine with the same size tires on smaller wheels.