I have a 2015 2LT RS and I'm going to be replacing the pads and rotors on all four corners. My question is how do I know if I have the 15" brakes or the 16" brakes? I've tried entering my VIN into parts websites and they list both as correct. I purchased the Power Stop Z23 kit and I'm hoping that I got the correct size rotors. Also the torque specs are very different if you have the larger rotors and I don't want to get that wrong either. I read that the larger brake package was called J60 and the smaller was J67 or J93 but how do I know which is on my car. Thanks for any help.