Do what you want.
We all Will.
But you haven't proven a thing.
Neither have you.
You have yet to show a real life drawn out court battle over AMSOIL
The records are sealed.
I know of no cases where anyone had a warranty problem using extended oil changes with an AMSOIL recommended fluid for 38 years
Your just not telling us.
millions of vehicles
Can you prove that with DOCUMENTATION, sure sounds like a Sales Pitch.
The proof is in the pudding (and the oil).
Amsoil sure turns into PUDDING after 17,000 miles.
So it is best to pick an oil with the best warranty
I already read Amsoil's Warranty, and its worthless, I could care less about Pennzoil's Warranty since the oil is fine for me.
Some oils don't seem to offer any written warranty. Your choice...
My uncle has a 1979 Pontiac with 220,000 miles that he has done yearly OCI's on the cheapest oil he can get his hands on, so he has done fine with his cheap oil that I would guess has absolutely no kind of WARRANTY.