I'd put a 6-pack (consumed individually at the sports bar of your choice) on it that they're identical. There are only so many product offerings to choose from and at this level nobody is making anything specific for the incredibly low volume that AMSoil is buying. AMSoil can tout whatever efficiencies they want but nobody is publishing actual numbers from a testing rig.
I mean, they are all tested to the same standard
(ISO 4548-12) But this is why I'd like to see Andrew test the EaO (along with the new Fram Ultra).
would have access to more insider info than I do, but AFAIK, AMSOIL still states that they use the Donaldson media, which RP wouldn't. They also used Donaldson's air filter media in the EaA filters, which I assume you've seen, so there was/is some relationship with Donaldson and AMSOIL. Those filters were also being custom made.
Here's an older pamphlet for the EaO, which shows 98.7% at 15 microns, tested using the same protocol that Andrew and everybody else is using, ISO 4548-12 (no mention of size however):
The RP tested well, getting 96.5% at 15-microns in the size tested by Andrew:
I will stand by my statement until proven differently. Also, AMSoil is crazy asking the 50%-70% higher pricing over the RP filter. It's just insane.
Which, in the context of this discussion, makes sense if
they are sourcing the media from Donaldson and having Champ assemble the can. If you look at some of the Fleetguard filters, and Donaldson filters, that fit passenger car applications, it's clear they aren't the one putting the can together, but they provide the media.
Of course, if they aren't still sourcing the Synteq media from Donaldson, then they are just over-charging for the filter. So, it comes down to whether AMSOIL still maintains that they are using the Donaldson media or not.