What size brakes are used by the E46 M3?
The standard E46 M3 is equipped with four-wheel vented discs measuring 12.8-inches in front and 12.9-inches in the rear. With the exception of U.S.-spec M3 models, the brakes also feature cross-drilled rotors and a two-piece “compound” design whereby the aluminum hat is connected to the outer portion of the rotor via steel pins, which greatly reduces rotor deformation under havy braking conditions. All M3 CSL and M3 ZCP/CS models sold worldwide are fitted with larger 13.7-inch front brake rotors that are also cross-drilled and incorporate the two-piece compound construction. The rear rotors are the standard 12.9-inch cross-drilled items.
