Does this filter have a bypass? I ran the wix/napa gold this season and my oil was black after 20 hrs. When I ran the the mobile 302 my oil stayed almost clear. The Napa has a bpv and the M302 doesn't, right? I searched and couldn't find the right thread.

It does have a bypass, the pressure differential required to open it is is fairly high though (18lbs IIRC), also it has a gasket on the valve to ensure it is sealed when closed, I believe the Napa/wix does not. M-1 filters also have anti-drainback valves.

I did have a problem with one of the old style M-1 filters where the internal screen partially failed. That issue has been addresed acording M-1. Not had a problem with the new ones but then i have only run about 5 so far.