Oil filters, all cars

I read a lot about oil filters lately and “efficiency” seems to be a key word to assess how good a filter is.
I see bypass oil filters take a small amount of oil from the flow and pass it through a filter that can catch virtually every particle. The oil is said to be analytically clean. I take it zero particles over one micron or similar great filtration results are typical. This is all the time after the initial cleansing, which happens quite fast.
So if the bypass valves are leakers, like on the higher end current Frams, or if the media shows pores open at 100x on Whip City Wrencher, what difference would it make? It’s nothing compared to a bypass filter where most of the oil is unfiltered, but the result is cleaner oil on the bypass filter. So the leaks and pores and “efficiency” rating seem meaningless.
I was trying to be happy with my Fram Ultra current model, but then saw the light leak tests, or paths the oil will go through unfiltered. On the surface that seems not good.

 

Very true. So I think the leaking bypass valves on Fram Ultra, most Champ Lab, and the Toyota oil filters won’t matter. Since a bypass oil filter “leaks” maybe 90% of the oil flow, and the other 10% filtered very well keeps the oil clean. But at first look, the leaking valves seem horrible.
I think full flow filters should not be leaking oil unfiltered though, bad engineering. They aren’t meant to do that.

 

Some engines have the bypass valve in the block but most have it in the filter. What I am writing about is the bypass valve not seating properly when it is closed.

 

Searched and found this leakage test. The older Fram Ultra has the bypass valve gasket shown in the pictures. It seems they changed to no gasket. He did find a leaking bypass valve in the Wix xp, and said if the test shows such leakage it’s a fail, and no reason to even do an efficiency test. Sort of long I don’t know if I watched all of it. He could get to the important parts and skip a lot.
I saw the Purolator had no leakage in the bypass valve.