I had 225/40's on mine as George said, rears not much of a problem but the fronts were just a ball ache. Even when I had my arches rolled and flared. More stretch/less tyre wall needed to get it sat good.
Looking at your sig has made me more determined to get some
So, i've had a look on tyrestretch and even 215 on 8.5 looks pretty gnarly, is that still pretty safe or will I into problems.
I thought the standard 18s were 8.5 by the way, i take it this is not the case?