BMC Performance Air Filter For Porsche CayennePrice Per Filter (Some Models Require Two Filters S,Turbo,GTS) PerformanceBMC air filters are designed and produced to ensure a higher air flow than original paper filters. In F1, for example, BMC cotton filters minimize the loss of air flow pressure passing through the air filter; this way ensures the best conditions for full exploitation of maximum power. Therefore the benefits of replacing the original paper filter with BMC cotton air filter,