I was wondering what the max tyre width could be on a 18x9.5 inch wheel for best handling.

255's would be best, if you go bigger the sidewalls may roll over under hard cornering.

yeh I thought as much, same width tread as the rim. Bugger. Is there any safe way of increasing rim width? The rims I want are two piece I think, if that helps.

No safe way to expand a rim, gotta get wider ones.

Is it possible then to get a bigger 18 inch rim and put the centre in? I don't really want to go to a different wheel.

No, any major re-working of the wheel will weaken unless the wheel is essentially re-manufactured, but the cost of doing this would be more than the cost of a new wheel.

lol yeh alright cool thanks:smile: