When the topic of Amsoil comes up it’s usually opening up a can of worms...
Historically, I’ve always used the boutique oil brands like Motul with an OEM filter. They always had great UOA’s and I never had any issues. Admittedly, I’ve also never had an issue with any of the top oil brands like Mobil1, Castrol and Pennzoil Ultra Platinum either and at some point you’re simply splitting hairs. This is particularly true for folks like myself that tend to over maintain their toys. No doubt Amsoil is a good oil with great UOA’s across the entire line including during extended intervals. I simply always avoided Amsoil because of all the die hard Amsoil fanboys preaching it’s merits and didn’t care for their buying process. But, one of my friends decided to become an Amsoil dealer so I helped him out. I suggest if you are really interested in Amsoil to do some research on BITOG and decide for yourself.