It's not the oil pressure, it's the oil flow (GPM) through the filter that makes the delta-p across the filter that the bypass valve actuates from. There could be 100 PSI of oil pressure, but a lower flow rate than on another engine that makes 75 PSI of oil pressure but has more oil flow volume out of the pump.I'm sure your right about Subaru but my infiniti VQ37 has the same filter number as a Altima 4 banger and I'm pretty sure the Altima don't make 100psi regularly like the VQ,s do so don't know how true oil pump pressure has to do with deltap...same filter number even for Acura tl and dozens of other cars and motors and pumps
And like I said in a previous post, a filter that is OK to use on a vehicle that has higher requirements (like a higher flow oil pump flow rate) is still OK to use on another vehicle that has less flow rate - like possibly your example of the Infinity V6 to the Altima 4-banger. If a filter can handle the most demanding oiling system out of the 100 of vehicles it can be used on, then it's still going to work on all the other 99 vehicles.
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