Continued OT
Yes even before the Amsoil ISO test results release, highly respected member river rat's similarly respected oil filter testing posted on this forum showed the no endcap type filters to be relatively inefficient as compared to their endcap type peers. His testing design was repeated on the
Mitsu Evo forum and it showed similar results for the no endcap type Mitsubishi oem filter. As aside, like the loss of Jim Allen posts, river rat's contributions are missed in this quarter.
As for the Honda A02 efficiency, speaking directly to the lead engineer at Fram Labs a few years back, while he didn't give specific efficiency data, confirmed the Honda oem to be significantly less efficient than aftermarket peers. Even gave me a possible reason, but admitted that reason to be speculation. Since Fram makes the A02 thinking he would some idea about it's efficiency. Not to mention, he's a straight up guy.
Now whether one believes the Amsoil ISO test data, up to the individual. Really makes no difference to me, I'll keep my opinion. I will say that many posters here that didn't care for the previous vague Motorcraft FL820S spec prior to the Amsoil test, embraced the respectable Amsoil finding when it was added to the their site. And the reason the Amsoil results are oft linked is because the OEM filter manufacturers generally speaking, keep their efficiency specs as propriety. That is a fact.
All that said, for many/most including some of those posting or reading this board, efficiency specs are nothing more than minutia. And as it's their vehicles, it's their choice. I'm cool with it.
Lastly and perhaps most important as it seemed to be lost in the Amsoil quote/comment, as the first sentence in initial post alludes to, filter flow has never been a concern of mine in pc use. So the flow vs efficiency discussion (ie. favors flow) is irrelevant to me. My .02+