I've done a quick scan through the Amsoil site, hard to do because it has a lot of links.
They do say that this oil and that oil is recommended for engines requiring API x, y, z certification, but they don't come out and say that they are actually certified.
There are on the other hand a number of web sites,
http://www.performancemotoroil.com/A...Licensing.html, for one, that go in to detail on why Amsoil doesn't apply for API licensing on all of their oils. Cost is claimed to be a key factor. I find this interesting because many of us look for API certification and won't buy an oil that doesn't have it. By spending the bucks to go through the API certification and licensing procedure they would expand their market considerably. $125,000 to $300,000 is pennies (or less) per unit sold and would be made up by the increased market I would think.
There are other web sites that mention that the real reason Amsoil does not submit all their oils for API certification is that they contain too much phosphorus (in the form of the additive ZDDP (Zinc Dialkyl Dithiophosphates))
Now I don't know how much of all of the above is true, but it is clear to me when I go to the Amsoil site that they sure don't go out of their way to tout unambiguously that they are API certified and licensed.
Personally I'll stay with an oil like Shell Rotella T, Chevron Dello 400, Mobile 1, etc. that I can go and buy from the auto store and that has the API rating clearly stamped on the bottle.
