I just picked up 4 17x9 rims with 38offsets. I was wondering what size tires will fit on all 4 corners without rubbing issues? Whats the widest tire combo for this setup?

For the rx8 you should run 245/45/17.

Rishie

What about something wider like a 265 or 275/40/17 ?Will they fit?

The 275/40/17 might work, but it will be close up front.

Rishie

^^ it will be more of an issue in the rear than the front with a 38mm offset

255/40-17 all around would be my recommendation, a 275/40 will be too squeezed on a 9" wheel, you won't get the extra contact patch area down