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The prevalent sources of phosphorous in motor oils are additives called zinc dithiophosphates (ZDTPs). Currently, these versatile additives act as oxidation/corrosion inhibitors and aid in the ability of a lubricant to reduce wear. The automobile manufacturers, however, have demanded that lubricants contain a maximum of only .10% phosphorous. Their reason is that some manufacturers believe that higher phosphorous content levels will poison the catalytic converters on their cars before they reach 150,000 miles, which is the number of miles that their vehicles will be required to pass EPA emission standards. There has not been total agreement within the automotive and lubrication industry about whether phosphorous levels over .10% actually do harm catalytic converters in the long run. What they have failed to make allowances for is the NOACK volatility of an oil.
The maximum allowable NOACK volatility percentage for the new SL/GF-3 passenger car motor oil specification is 15%. Most of AMSOIL motor oils are in the 5% to 8% NOACK volatility range. Studies have shown there is a correlation between NOACK volatility, oil consumption and the amount of phosphorous from motor oil that will end up in the exhaust gasses. Therefore, oils with higher levels of phosphorous but with low volatility, such as AMSOIL motor oils, present no more risk to catalytic converters than low phosphorous oils with higher NOACK volatility. This has also been demonstrated for years in actual application through state mandated exhaust gas testing on our Dealers' and customers' high mileage vehicles using AMSOIL synthetic motor oils. State inspectors are continually amazed at the low emissions levels generated by vehicles using AMSOIL products. So much for poisoning catalytic converters.
I find this interesting also. Sure, the NOACK volatility has a relation to the phosphorus in exhaust gasses, but they've neglected the factor of oil consumption. All engines use oil. Some more than others, and some MUCH more than others. Oil loss isn't usually because of burnoff, although this contributes some, it's usually the normal amount getting by the rings and valve stem seals. This gets burned and releases its phosphorus. In a brand new engine that burns very little, not a real problem. If you're using more than a little, watch your converter.
I have a feeling the API set a limit so that it would be safe in an oil burner to not plug the converter, too fast anyway. I would have serious doubts about running Amsoil in one of these.
It's not just the old vehicles that burn oil regularly. I've seen new vehicles blowing blue smoke, and my dad's chevy used about 1 quart every 1000 miles when it was new and using synthetic. I had 5 or 6 quarts in it by the time the GM oil life system said to change it! (I switched to dino and it doesnt use any now, go figure)
Had I used Amsoil in the above mentioned chevy, would I have had converter problems? Maybe, maybe not. But I'm sure the chance would have been greater.
It is a given that the major vehicle manufacturers and the major oil companies have for decades worked to develop engine oils that are technologically on the leading edge (there is a reason we no longer depend on single weight oil). Major oil manufacturers (who happen to be API certified) and major vehicle manufacturers (who happen to have a vested interest in how long their vehicles last) recommend oil of x quality and oil changes at y intervals. The major oil/vehicle manufactures have spent tens of millions of $$ on oil research. Should i instead follow the advice of a little company that doesnt want to or cant get API certified? amsoil may be an ok oil, who knows? But why should i pay big bucks for oil to a person (the amsoil salesman) who stands to profit a bunch when i can safely utilize the expertise and decades of oil research experience provided by the oil manufacturers/vehicle manufactures by simply buying a good quality API oil, of the right API rating, and changing it according to the manufacturer's recommended change interval? Something about amsoil reminds me of PT Barnum's famous statement "a sucker is born every minute" But obviously, anyone who wants to try/use amsoil then that is their choice. IMO.
Last edited by 03f150man; Mar 2, 2004 at 12:01 AM.
Hey, OilDude, you wouldn't happen to be an AMSOil distributor, reseller, or prime customer, or primate customer, or whatever they call it, would you?
I'm on record, and my web page back me up: I sell software and motorcycle accessories. As far as oil and trucks go, I'm just another consumer trying to find my way through the marketing hype and mass confusion.
I'm curious: what's your story?
Last edited by marklawrence; Mar 2, 2004 at 12:04 AM.
Amsoil threads always end up with someone attracting the wrong kind of attention to themselves and losing their posting privilage. You guys have put a lot into this thread already and I don't want to disrespect that by removing it from the forum. So instead it's locked and still available for viewing, if not replys.
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.