Originally Posted By: ZeeOSix
If the oil pressure gauge is after the oil filter and the engine uses a positive displacement pump (most likely does), then you'll never know what effect the restriction in the filter has unless you rev the engine enough to see the max pressure produced when the oil pump is in pressure relief mode. If the pressure gauge was before the filter, then you could tell if filter A is more or less restrictive than filter B.
Correct. But that's still an entirely reachable situation (especially on a cold start), so it's not hard to test.
If the oil pressure gauge is after the oil filter and the engine uses a positive displacement pump (most likely does), then you'll never know what effect the restriction in the filter has unless you rev the engine enough to see the max pressure produced when the oil pump is in pressure relief mode. If the pressure gauge was before the filter, then you could tell if filter A is more or less restrictive than filter B.
Correct. But that's still an entirely reachable situation (especially on a cold start), so it's not hard to test.
