Originally posted by Abus:
I'm not comfortable with saying that AMSOIL would have to downgrade their formulations to meet API.
A. Phosphorus is not the only way to built a strong additive package, though it happens to be a relatively cheap way.
B. Last I checked VOA's of ASL and ATM Amsoil showed under 1000ppm phosphorus anyway, so they'd be under the API cap.
I beleive you are correct on " B " and for " A " one has to look no farther than the new Mobil Clean 7500 for proof . They are calling this oil a blend but in my opinion it's as much of a synthetic as Amsoils 7500 , Valvolines and other brands non pao/ester oils at a much lower cost . $2.18 per quart currently .