Originally Posted by
pawpaw
Lets think about this some more.
Since we don't know to what specifications Napa has their filters made, nor do we know when they may change vendors or filter constuction to help their bottom line, (after all they are in business to make a profit) & napa doesn't make engines nor test them for hours on end, to decide how their filter should be made.
But Ford does & has to warranty their product, & specifies a filters construction, inside & out, after all of those hours of testing & engine tear down & inspection.
So it seems to me Ford would likely know how to specify the construction of a filter for their engines, or when any changes may be needed to a filters construction later!!!!
Thus it seems to me the benchmark to meet, is still the manufacturers product!!!!
That would be great if Ford actually did all those things that you mention.
The reality is that the test data likely came from the filter manufacturer. And the specs likely came from industry standards.
Now Ford may specify a more expense filter media, but that does not mean that no one else uses that same media in its filter.
And you forget, Navistar made (and still makes) the 7.3 and it has its own specs, which are public knowledge.
Ford's specs (if they differ from Navistar's specs) are also well-known to the other filter manufacturers. Long gone are the days that manufacturers can void your warranty for not using OEM parts. Just look at the back of any motor oil for the long list of specs that particular bottle of oil meets, include Ford and Honda's specs for 5w-20. So aftermarket parts manufacturers know full well what the OEM's require. It is no big secret.
So while I agree that all things being equal, going with the OEM is a good choice, paying a great deal more for OEM may not be the best choice.