AMSOIL not API certified?

You should visit the extensive discussions on the internet group "Bob is the oil guy" Just google bitog. I suggest that the phosphorous/catalyst question is a very good one for you to present there.

They also have a virgin oil analysis library there which shows two (other) versions of AMSoil with about 1200 ppm P. Mobil I has about 700 ppm P. I cannot tell you if this difference is critical.

 

Amsoil's site says:

http://www.nordicgroup.us/oil.htm was last updated in 2002, so maybe things have changed?...

 

Most of the Amsoil oils are not API Certified. The only ones that are certified are hydocracked/hydro processed group 3 (petroleum) XL series oils, and the Diesel Blend -Hence the name "American Petroleum Institute"

The main reason IS the phosphorous level. Does phosphorus damage cats? Yes! This isn't the only reason.

But, only if the oil volatilizes/vaporizes and ends up in the exhaust stream or the engine burns oil. If you have any engine that burns oil will damage the cat anyway! The phosphorus rating from the API is to protect the cat for 150,000 miles.

If you were to use a petroleum oil or synthetic oil and change every 3000-5000 miles and this oils had the low NOACK rating you are going to introduce just as much if not more phosphorus into the exhaust stream, which could damage your cat. The maximum allowable NOACK volatility percentage is 15%. Most of Amsoil oil are in the 5-8% range. In many cases more than half less than the allowable limit than set by the API.


Since 1972 Amsoil has been formulating oils for performance and reduced engine wear while extending drain intervals. Now I know that cats have not been used since 1972 but how many people have you heard of that run Amsoil and damaged cats?

 

The AMSOILs you would be putting in a Prius are API certified. This is very old info you are dealing with. AMSOIL does not even offer a non-API oil available for the Prius presently. The Gen I and Gen II would use 0W-30 or 5W-30, both API certified. The Gen III uses 0W-20 which is API certified. Since I have all of the above cars and have been using AMSOIL for many years now with over 10+ UOAs, I have the proof that the 0W-30 is a very good long life oil. It will take some time to evaluate the new 0W-20.

 

Actually this is not old info. The ONLY API Certified oils "the API starburst" by Amsoil are the XL (group 3) line and the diesel blend.

Not that this is a bad

 

Your right, I'm wrong. I went back and read the fine print on the oil containers. "For use in engines that use API certified oil..."

 

You brought up the KEY points right there!

An oil that will last 20,000 miles with no noticeable oil consumption, is far better for the motor and the emission controls, than an oil that is changed every 3,000 miles and uses half a quart between changes

Remember that the bare minimum spec API oils are designed to shear ON PURPOSE. Thus, oil consumption