- Jun 19, 2019
- Killdeer, North Dakota
Upon doing a little research on the websites of Royal Purple and Amsoil I noticed that Amsoil has published a 99% @ 20 micron efficiency rating while Royal Purple has published 99% @ 25 microns, 98.7% @ 20 microns, and 80% @ 10 microns. As these two brands have been acknowledged as having similar, if not identical, internal filters in the past I do wonder if Amsoil has had the filter media in their specific brand filter improved or perhaps it has always been that way for both brand filters but a newer form of testing has shown improved results? As far as Fram goes the Ultra/Titanium internal filter is officially rated as 99% @ 20 microns and it has been suggested here on BITOG that the efficiency may be as good as 98.7% @ 16 microns and 80% @ 5 microns but those are unofficially published numbers. So as far as efficiency goes it appears that Royal Purple / Amsoil have produced an oil filter that is at least as good as a Fram Ultra/Titanium and as far as officially published efficiency ratings it may even be better.