OK - more data for non-believers ....
Toyota 3.4L v-6
Looking at them with Premium filters typically 95% or better (Ultra, TG, Boss, PureOne, etc) versus Toyota brand normal filters at 60% or so (very loose) filters.
Compare/Contrast wear rates at 100k miles and 200k miles.
Theory is that "better" filters would make engines last longer; that should be reflected in the wear rates being lower from UOAs correlated to premium filters.
And yet reality says .... Nah - ain't true ...
Wear rates were SLIGHTLY lower with the premium filter at 100k miles exposure, but at 200k miles, the disparity all but vanished. Maybe it just takes longer for engines to burnish in with premium filters in use?
Regardless, the disparity is TINY and not consistently "better" from metal to metal.
Look at the stdev; there is huge overlap. DAILY USE FACTORS AND TYPICAL NUANCES OF EACH INDIVIDUAL ENGINE HAVE FAR MORE AFFECT ON WEAR THAN DOES A MODERATE FILTER EFFICIENCY CHOICE.
The data shows that filtration is not having a substantial effect. The conclusion I draw is that once oil is clean enough, making it cleaner does not substantially increase the longevity of the equipment.
I cannot tell you what level of clean is necessary; I can only say whatever that value is, Toyota seems to have figured it out because tighter filtration is not making a tangible improvement in wear rates over the LONG term. As I have said before, it is more likely that the add-pack (controlling soot) and the TCB (controlling asperitive contact) in short-to-moderate OCIs that makes all the difference.
If we wanted to know how important the filter is to the overall system in terms of engine wear, we'd need a control group with NO filter, to see the effect as a singular variable holding other inputs the same. To date, I've not seen any study ever attempted in that regard. All the SAE studies to date have either been run in grossly exaggerated conditions that completely ignore the topic of OCI, or they were run with really outdated equipment and lubes. None of these have any bearing on today's engines and lubes.
If you are going to run really long OCIs, where contaminant loading might well usurp the host lube's capabilities if unassisted, then BP filters and premium filters would be paramount to success. But if you're running "normal" OCIs (typically set by the OEM) and using a decent fortified lube, the filter efficiency just isn't important past a certain point; clean enough is good enough. And "better" does not reveal itself in reality.
The reality today is that engines are designed, made and operated well enough that lube filters matter, but only to a certain point. In fact, it's been that way for well more than a decade now. Some engines just continue to soldier on simply because they are well designed and are almost immune to wear, and the reality of catastrophic events are more likely to take them out of service than a wear-induced death. Ford 4.6L mod motors. Toyota 3.4L engines. GM 3.8L v-6. Etc ... some of these run seemingly forever and never get anything but routine oil/filter changes with jobber type products. How many CrownVics are out there still today with 300k, 400k, 500k miles on them running in taxi service? Do you think they are getting Mobil 1 and Fram Ultra filters????
My son's 4.6L Grand Marquis was running great at 126k miles, until a jerk fleeing police crashed into him and totaled it. My wife's 2005 Grand Marquis was running superb at 255k miles until it also was struck and "totaled" (we bought it back for my son). The UOAs from my 4.6L fleet (3 Grand Marquis) show that normal oils and filter are likely to make the engine outlast the car either from crashes, rust degradation, etc.
Anyone who wants to buy the "best" is welcome to do so; spend your money in a manner you see fit.
Here's the Toyota 3.4L filter data .... As you can see, premium filters really don't alter wear much and the longer the engine wears, the less effect there is.
Maybe it just takes 150k miles to "break in" a 3.4L Toyota