I am planning on buying a set of wheels and tires from someone tonight. Specs are
Front: 255/35/20 width 9 offset 25
Rear: 285/30/20 width 10.5 offset 27

I have a g37 AWD coupe. I did the math for the rolling diameter and its 1.1 percent which falls under the 3 percent rule.

wiht the offsets, would I rub or would I need spacers?

 

I bought used ones that were F:20x 9.5 +18 235/35/20 and R:20x 10.5 +24 275/35/20 and it rubbed a lot in the back, I had to stretch the rears with 255/30/20 for it to work with my coilovers and then I still had to shave the rear brackets. Good luck!

 

you'll have to trim your rear bumper bracket. I am running 255/35/20 on 20x10 +20 on the front and 285/35/20 on 20x10 +25 rear and had to shave it almost all the way, but now no rubbing whatsoever.

 

Just double check if you can go staggered with the AWD model. I've read and been told numerous times that's a bad idea.