Hi All, I did a search on this till I was cross-eyed and still didn't find the answer. I am considering switching to Amsoil. I know their Signature Series has a superior ad pack. When I was searching their website and their "faqs" section, This question was asked: What kind of base stocks does Amsoil use? Are Amsoil synthetic lubricants PAO based? Here is their answer that I copied and pasted here:
It would seem to me that they are not strictly using Group 4 PAO base stocks. To me, their answer looked elusive. At the risk of igniting a "firestorm", shouldn't something this expensive be group 4 PAO based? Has dino base stock refining gotten so good that it doesn't matter anymore? The reason I'm wanting to know is because it's not too easy to do my own OCI's like I used to and am looking to extend them. (I've started using oil analysis too). Thanks.......
Answer: AMSOIL maintains formulation details as proprietary and does not divulge specifics regarding the type of synthetic base stocks used in its synthetic lubricants. AMSOIL developed the world’s first API-qualified synthetic motor oil in 1972 and has remained the leader in the synthetic lubricant industry by continually researching new technologies and demanding only the highest-quality raw materials. As the company moves forward with new technologies it is increasingly more important that this information remains proprietary. AMSOIL views synthetic base oils the same as it views additives, with each having its own set of unique properties. AMSOIL does not insist on a particular type of base stock, but insists on particular performance parameters. AMSOIL chooses whichever synthetic base stock or combination of base stocks delivers the desired result and tailors its lubricants to be application-specific (gasoline, diesel, racing, transmission, gear, extended drain, extreme temperatures, etc.). At the end of the day, the type of base stock used to formulate the oil is inconsequential; the product’s performance is what matters.