I put a 225/40/18 on the front and had the oem size 225/50/28 on the back and car was doing crazy things like abs was actuating at random times. I don't know if that size would be ok on all 4 wheels, but I think having the same size tire would be fine. I ordered a set of 225/45/18 to put on an extra set of wheels that I have that are 18x7.5 and I'm hoping they work.