I apologize if this has been beaten to death. I've searched many places and found a spreadsheet but my tire size is not listed. I recently bought a 2003 Z06 and prior owner just installed Extreme Contact Sport tires on the rear in the (unfortunate) size of 275/35/18. I need to replace the fronts and I think the following size will maintain the correct ratio of front-to-rear balance to keep the TC and AH functional: 255/40/17. The rear diameter is 25.6" and the front will be 25". Is this close enough to keep TC and AH from going nuts?