Amsoil has some good and mediocre products just like everyone else. I use a couple of their niche products, but no oil. Pricing is criminal and when one tacks on shipping if they don't live near a DC, that just adds insult to injury. It is indeed a cult like following. I can get very high quality oils and greases from a company that has been making lube products in N. America longer than anyone else (over 175 years), is one of the top 500 most technological advanced companies in America, developed the lubes for the Apache Attack Helicopter and M1 Abrams tank, makes some specialty greases that even Shell oil could not replicate so Shell buys it from them, pricing that competes favorably with anything on the shelf, and delivered FREE to my home. Schaeffer oil. For everything from my semi truck on down to my portable generator and lawn mower.