0W20

[1stToyota]

Originally Posted by firemachine69

Almost all of the AMSoil line-up is "true" synthetic (commonly referred to as 'group 4'), Mobil 1 is an extremely hydrocracked dyno oil (referred to as group 3 or 3), meaning not "truly" synthetic in that sense, but acceptable by the governments definitions.

I think they (Amsoil) might even have some 'group 5' products, but not so sure about their XL series being anything but 'group 3' ...or at least that's what I was told about their popular XL series.

edit:

http://www.amsoil.com/articlespr/article_xl7500.aspx

All Amsoil XL series is group III to get API approval:

"AMSOIL Changes XL-7500 Formula To Enhance Oils, Stay Competitive

Q: AMSOIL will be using a different formula for its XL-7500 Motor Oils. Why did AMSOIL change the formula?

A: Our XL-7500 oils are the oils of choice in the retail oil change market, and primarily because of warranty concerns the customers in this market require API-certified oils. In order to obtain API SL/ILSAC GF-3 certification and still remain cost-competitive with the other oils sold at retail oil change outlets, we had to change to Group III basestocks. To obtain API certification with our top tier basestocks would have priced our Dealers out of the market.

Q: Are Group III basestocks synthetic?

A: Yes, they are synthetic. Group III base oils are highly processed oils and were classified as synthetic in 1999.That year, the National Advertising Division (NAD) of the Council of Better Business Bureaus ruled in a complaint by Mobil Oil Corp. against Castrol North America Inc. Castrol claimed its product, Syntec, was a synthetic oil even though it had used Group III base oils since 1997. The ruling by NAD said Castrol presented evidence that constitutes a reasonable basis for the claim that Syntec, a Group III based formulation, is synthetic motor oil."