A good synthetic vs conventional comparison below.(Before R&P, I believe EP was used).
Honestly I’m not to impressed with either of the results. I’ve seen very high mileage internals look like new with M1 TriSyn PAO/AN/Ester formula. Which is now used by HPL courtesy of Dr. Rudnick.
I called PG because of this confusion. Official ISO numbers for PG made 10K filters are:
98.7%@15 microns
99.5%@20 microns
99.9%@25 microns
Marketing from the various brands decides which to publish. Service Pro shows all.
Thanks for your hard work. Much appreciated. Since the Royal Purple, Amsoil, and Endurance are the same filters this is a good starting point(to add an Endurance at 15). Hopefully as time goes on we’ll have more data!
It was me. Holes were carefully drilled then opened with needle nose for a wider view. Leaf spring was 100% not disturbed. That’s exactly how it came from the factory. Many have been tested out of the can. My test was an in can test to prove assembled pressure made no difference. If you search...
Here’s the master thread on the Endurance.
Nobody is saying it’s “catastrophic” it’s just not the efficiency you’re paying for IMO. It’s a manufacturing/QC defect.
https://bobistheoilguy.com/forums/threads/fram-endurance-flashlight-test-in-canister.386911/