ive got 18x9.5 99 C5 rims. what is the biggest size on can put on the back? also will 275/40 fit on the front? the car is lowered with eibach prokit and bilsteins. think they will rub??
justin

 

Stock sizes really belong on there, you could stick 255s on the front though, you could even go wider, but stock or 10mm bigger is all I'd go.

 

I run 275/40x17 on all four corners on my '95 Trans Am. I use ARE 17x9.5 rims with stock backspacing (whatever that is). The '97 Camaro SS comes stock with 275/40x17 all the way around. I have no idea what that equates to in an 18" tire size. My T?a is lowered using HAL shocks and springs (adjustable coil overs) now but was previously lowered using an Eibach Pro Kit. Never had a problem with tires rubbing on the road courses or at the drag strip.

Later ... Larry S.