Originally Posted By: Rand
What is (B.) based on.. seems kinda random.
I think he's pointing to, generally, a better flowing filter, for a longer OCI. The Germans have done that for some time already with their fleece filters. They may not get the 99.9% efficiency at some low micron level, but they will handle an outrageously long OCI without clogging up.
And his point C is well taken, too, considering that something with a thread end bypass and sized like the Wix 51365 has significantly less filter media than the dome end bypass Bosch 3300, for instance. On a short OCI, it's not likely an issue.