what large wheel and tire sizes work on a C4S?

 

I have an 09, for that car the front are 8Jx19 ET 57 (235 width), and rear are 11Jx19 ET 51 (305 rear). some winter tires are 295 in width with the same offset wheel will work fine.

I looked for 18 inch wheels for winter and had a hard time finding something that would fit. Good luck.

 

Go BIG!!! I have 20's on my 997 4S. Im running 325 25 20 in the rear. The ride is very similar as to when I had my 19's.