Maximize tire size
The stock sizes for GS and Z06 w/ 18s & 19s is 275-35-18 front and 325-30-19 rear. (Who knows what the previous owner was thinking?) Those sizes fit with no rubbing and the car performs very well. There are lots of choices of different tires in those sizes so why not stick w/ stock sizes?
Because everybody loves big fat tires!
Several other size combinations will work, like 285-35-18 front and 335-30-19 rear for example. And lots of guys run 345s with an appropriately sized tire on the front with no ABS trouble. just make sure that the % difference between front & rear diameter is very close to stock. The tire calculator is your friend here.
If your local chain tire store is clueless, and most are, check out Discount Tire and Tire Rack. (same company btw)
I thinking when he or she was buying the tires they choose base and didn't know the GS is same as Z06. Thank you for different size maybe I can find matching set with that combo.







