DeutschTuning proudly offers BMC C63/GLC63 (W205/X253) Air Filters. We highly recommend BMC since they provide better air flow from stock while still maintaining proper filtration to keep your engine running smooth. OEM paper filters present an elevated resistance to the passage of air and consequently a reduction in engine performance. Compared to a paper filter the BMC air filter permits a notably higher air flow passage, producing less than half the Pressure Drop (difference between the air pressure before and after the filter element) over the paper filters. This doesn't compromise the filter's engine protection efficiency: thanks to the combination of the different oiled layers, containment of all impurities is guaranteed as far as 7 microns, while paper filters generally require total filtration of particles as small as 10 microns. So BMC air filters let more air into the engine while still protecting it better than paper ones. In addition, a traditional paper filter must be replaced regularly during routine maintenance whilst the BMC air filter is reusable and has a general life-span equal to that of the vehicle.