whats the largest tire width wize i can smack on the tC w/ stock rims....dont flame me f*kers......

I suppose that depends on what you mean by "can", and how safe you want to be.

It's technically dependent on the aspect ratio of the tire, not just the wheel width. For both safety and optimal performance, if you're using 45 series or lower, then the wheel should be at least 85% of the tire width. For aspect ratios of 50 or greater, the wheel only needs to be 70% of the tire width.

This means that the 215/45 on the tC's 17x7" wheel is perfect. That said, many people have used 225/45 on the stock wheel without issues, but I wouldn't recommend anything wider without going to a 50 series tire, which also isn't recommended. Now I'm sure you could find some place that would sell you a 235 or even a 245/40 and get them on the stock wheels, but it wouldn't be safe and the performance would suffer too.

245/40 is probably the largest tire you can go with stock wheels

Our fitment team recommends 225/45R17's!

Upgrade your wheels to 17x8 and go for the 245.40.17. With the stocks go with a 225.45.17. If you put the 245.40.17's on your stocks they'll look like donuts. but if you must, against recommendation, anyway... at least look at the Falkens, they tend to run a little narrow.

DONT DO THAT! haha im jk do whatever you want. its your car.