Can you fit 245/45 or 245/40 tyres onto the standard R32 GTR 16" rim? Would it cause sidewall problems? I'm thinking mainly for track use? Yes I know the obvious answer is change to 17s, but assume that isn't an option at the moment.
I'm sure its possible. As I understand it the wider tyre makes no positive difference if it's too wide for the rim. 245 I think should ideally have a 8.5 to 9" tyre. Check the website of the tyre manufacturer and it'll say if an 8" rim is suitable