9.5 All the way around
 

Hi guys, I just recently bought a 93 300zx N/A, and just wanted to know if I could run 17x9.5 all the way around. The car is lowered about two inches on Megan Racing spring and Koni yellows. I am currently running 17x8 (f) and 17x 9 (r 40 offset) no issues and just wanted to know some input. Thanks

It's definitely possible, even seen someone running 10's all around. It almost completely depends on your offsets. Let's say your current rear is right at the outside edge where you're comfortable having your wheel, the 9.5 must have an offset of 1/4" more than the current wheels. 40mm + 1/4" = 46.35 so ~46/47 offset should bring you outward the same distance.

The tires come in to play a bit too with their bulge, but that's another story.