I have recently installed a dual filter setup and have a question for anybody who might know. I currently am not using a bypass filter, just two stock Napa Golds. My question is this, Should I change both at the same time, or alternate changing (ie. Change one with every oil change). The reason I ask is that in some of the reading I've done there were people who claimed that oil filters actually get more efficient at removing particles after they have been used a while. This logic seems sound, in that as they clog up with soot, they will filter better, but let less oil through. By alternating the replacement cycle, would that in effect increase the efficiency of the dual filter setup.

I'm just wondering and would appreciate any input on this. Eventually i may try a bypass filter, but I prefer to use parts that are readily available and they don't seem to be. Shipping to Alaska is a little $$$

Seems they've been trying dual filters on 18wheelers here but given them up for some reason. This should tell you something.

You must always flow enough oil. I would change both each time and use bypass filters.

I believe the NAPA filters you are using have bypass valves in them. A non bypass filter would leave them open to unhappy customers.