We call for a 12-18psi bypass valve If I recall correctly. It's not a 100% science in bypass valve technology, just as long as it has one in the general area of PSI, you're good. However I did read that the location of the bypass valve my play a role in how good a filter is. b/c when the valve opens oil washes over a dirty filter and then goes into the engine. I know the PL20195 is like that b/c I opened it. Next I'm going to cut Pure one OEM filter and OEM Mobil 1 filter open see how they have it placed. Ford filter is supposed to have the Bypass at the top, meaning oil doesn't wash over the element when it opens. I'll update everyone when I get some more filters that i'm interested in cut open.