Max Wheel Size
 

I got my tC about two week ago, white 5 speed. I was wondering can a size 18 x 8.5 width can fit on a tC.

8.5 is a bit wide.. you may need a spacer.

Check Tires.com... they have the sizes that will fit.

Oh yeah, get this.. supposedly our tCs will take 20s... sweet!

Yeah in theory you can put 20's on these bad boyz but it will ride and rubb like crap. A good pair of 18's or 19's should do. Watch the width though.

Found out 8.5s should work without spacers.. although the spacers will give it a little more of an aggressive-BMW style look

A more aggressive look with the spacers will make the tC look even better, but I guess Its a personal thing. Try H&R hubcentric spacers, they are a great product.

19x8.5 up front 19x9.5 in the rear, looks really good

brent

8½ Width
 

You should be able to run a 19×8.5 wheel with ET45 or so with 235/35R19 tires no problem. If you space it or use a lower offset, you may need to roll the fenders. It will look alot nicer though.