I'm looking for Extreme Performance Summer tires on Tirerack and none of the really high end tires come in 235/50/R17. Has anyone tried 245/45/R17 on their rear 17" OEM rims? These are a lot more common size it seems like. Can you vary the 50 to 45 ? Does that just leave more wheel well showing? Will 235 work on the 8" wheel?

 

8-inch wheels offer lots of variables. You can go anywhere from 225 to 245 mm.

 

What about going 45 rather than 50? Does that just leave more of a gap between the tire and the fender?

 

There are any number of tire calculators on the net that will tell you the overall diameter of various combinations. Not rocket science, you just have to spend a couple minutes searching and reading.

A 245/45-17 tire will have about .6 inch smaller diameter than a 235/50-17 tire. Since it is the radius of the tire that determines gap between tire and fender, that would give you .3 inch more of a gap. So between 1/4 and 1/3 of an inch.

 

I think I went with a 255/45/17 on my stockers... not exactly sure though

 

Pretty much stuck, like the G35, with that 8" wheel in the back. Haven't found a 255 with the right diameter and the 265's that do fit require a wider wheel. That wheel limits you to oem sizes.

 

What would happen if I went with 225/50/17 or 235/50/17 or with 45 series? Will it work?

 

About an inch shorter than what should be on there.