I went from using the Mobil1 m1-113 oil filter(for almost 20k since new) back to the AC Delco PF48. However I am still using the Mobil1 5w30 ext life synthic oil (which happens to be dexos1). The valvetrain noise would only happen for 1-2 seconds max right after start up. I have also notice that before with the Mobil1 filter my oil pressure guage would stay mostly around dead center on the guage at all times, now with the AC Delco filter the guage drops a little from center at idle or really low rpm but dramatically raises past center under acceleration or at higher rpm's. In addition. when I had the filters side by side, the AC Delco's six holes are larger than the Mobil1's six holes, improved flow mabey??? Good luck...
Ok, I sorta see where yer going here, but I think that your thinking might be backwards:
For starters, I'm concerned that my oil pressure drops so low at warm idle while in gear. It's between 1/4 scale and dead center which is I think is about 30 PSI:
However when racing it up a bit (1,500-2,000 RPM), it just crests 1/2 way, or dead center as you say which is probably a tad over 40 PSI:
In years of rebuilding motors, "higher" oil pressure was always seen as the better thing, not "lower". So if you had a filter that was yielding a "higher" oil pressure at idle, then to me, this was the better filter, no ?
As far as hydraulic lifters, and oil film barrier bearings (rod & crank bearings), you typically want "pressure", not "flow". In fact, as engines wear, higher "flow" (associated with increasing bearing clearances as engines wear) is seen as a "bad" thing since higher "flow" usually results in lower overall "pressures".
Edited by mokeman3, 10 November 2011 - 11:48 PM.