I am wondering if the extreme efficiency of the fram ultra (99% @ 20, 94% @ 10, and I even heard someone say 80% @ 5 microns) would create a large pressure differential and cause it to bypass often. The bypass valve is extremely flimsy and easy to push because of the weak spring and plastic valve. This seems like the biggest weakness of the ultra. If it bypasses often, that 99%+ becomes 0% lol.
Also, wouldn't the Wix XP have the lowest pressure differential of nearly any filter? (with fiberglass media and 50% @ 20 micron efficiency). If so, you get the filtering efficiency of many OEM filters, but with excellent flow, and the toughest construction.
Also, wouldn't the Wix XP have the lowest pressure differential of nearly any filter? (with fiberglass media and 50% @ 20 micron efficiency). If so, you get the filtering efficiency of many OEM filters, but with excellent flow, and the toughest construction.