On another forum I frequent, there is an oil section, and one of the posters there wrote the quote below. I invite those who know a lot about these oils to comment.
quote:Is it true that Amsoil is purely a blender, buying basestock PAO from Mobil and additive packages from Lubrizol? And is Super Syn (whatever it is) really superior to Amsoil's add-pack?
In basics, there are two components that are used in the manufacturer of todays motor oils. There is the basestock and there is the additive package. It is the balance between the two that makes an oil good or great. Amsoil uses a PAO basestock made by, guess who, Mobil. Their add packs come from Lubrizol. Amsoil is a blender not a manufacturer of motor oils. They do not have any refineries making product from crude oil. Their PAO basestocked oils are not API certified because the add packs exceed API limits. The primary reason is because of the levels of Zinc and Phos used in their formulations. These anti-wear agents are suspected of being harmful to your emmissions system. In the non-scientific testing I have seen, the Mobil One will out distance the Amsoil. If I had to guess I would probably say it is due to the inclusion of Mobils Super Syn. Amsoil will be higher in cost due to the MLM marketing where many hands are in the pot seeking profit. If you have the need for a synthetic, Mobil One is a good one.