Thanks. I have an 18x9 front wheel. I thought the common belief was that the rotor usually has to be 3" smaller than the wheel diameter.
No, I do not need a 15" rotor to stop the car, I was just wondering and mulling the options.
It depends on the shape of the parts but back when I was building 13" brake kits they were all designed to work with Ford Mustang 17 inch rims. So if your 18" rims are caliper "friendly" then you should be able to put a 14" rotor in there. A 13" rotor with a big caliper should easily fit inside an 18" rim unless you have the world's worst wheel design.
