On the topic of filters, I have looked inside the Fram PH8316 equivelant to stock filter and it has a metal plug about an inch deep inside? I don't think this is a bypass, do you have any idea? Would you agree that this plug would reduce the efficientcy because only one inch of linear filtration is realized, which then in theory would equal one third total filtration capasity. I can't see it being a bypass because if pressure is needed then the oil should flow through the media before activating the valve? For what it's worth the lowest micron count filter I found was Amsoil EA034 @ 15 micron absolute.