As long as you use o.e. rotors (cast) on the front wheels of your mercedes, you must use o.e. brake pads to keep the factory level of braking. The o.e. pads are full of graphite which will constantly make your front wheels black. When my rotors finally needed replacing, I bought Zimmermann cross-drilled rotors instead of o.e. Then I bought Rotex Gold brake pads which have no graphite in them and do not make the wheels black. What a difference! Same braking power. P.