I did a quick search and didn't turn up much although to be fair I didn't page through all that much.

I've got a 2012 G37x sedan with 225/50/18 stock tires and I'm wondering what is the widest tire I can fit without modifications? There seems to be a lot of clearance so I'm pretty confident I can fit a 255/45/18 but was wondering it anyone has been able to fit a 285/40/18 and if so with what offset?

 

It's the first sticky in the wheels & tires sub-forum
https://www.myg37.com/forums/wheels-and-tires-307/