Understood, but there has to be a reason GM has had it and continues to have it. Not trying to start a battle or anything, just thinking out loud...or typing out loud...
It should only open up when there is 7-9 PSI difference between inlet and outlet (in my understanding). If there is more restriction than that, you would be under the assumption that the oil filter is clogged for whatever reason and the engine will soon be starving of oil pressure. Pressure valve opens up to allow the engine to maintain proper pressure, although your oil is now no longer filtered.
So what's worse, not enough oil pressure or dirty oil? You have to assume that you have something already in your oil causing the filter to be clogged, and that same oil would then be distributed to bearings throughout your engine if the valve opens... but again, vs having no oil pressure.....
Almost a chicken vs egg conversation!
