I was running 185/70 13's when I first put my car on the road but had rubbing issues at the front. One reason was the wheel offset, but the other issue was the overall diameter as it rubbed on the toe board. I've since switched to 185/60's, but it reduced the ground clearance and has increased rpm at speed (smaller diameter). If I were to do it again, I would go for 175/70's in the front and 185/70's in the rear (S2 with a Zetec so a bit more weight in the back).