Sport Cup 2 Tires, when do they need changing?
 

Everyone who sees my Sport Cup 2 tires (and are not a Corvette owner) on my C7 Z06 tells me my tires are bald. I tell them that is the way they came! But how do I know when it is time to change them since the tread is so thin to begin with?

All tires manufactured have tread wear indicators that show when you get down to 2/32nds(?) of an inch which is minimum legal tread or you can have the tread measured at any place that sells tires. I replace my tires whenever I feel the traction is less than desirable.