Larry Crider
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Modern engines are becoming ever harder on the motor oil that lubricates them. As engines and oil sumps have gotten smaller reducing the volume of oil the engine holds, performance enhancing additions like turbo changing have become common.   

Throw in government mandates for constantly improving fuel economy and pollution control, and you have constantly increasing demands placed on motor oil.    

Between advancing new technologies, and ever increasing performance mandates, the oil formulation industry has been continuously changing….. As it must!   

API (American Petroleum Institute) has represented the interests of all the oil manufactures and first created oil classification groups in 1947.   

Since the “S” and “C” categories were introduced about 1970, API has worked closely with both ASTM (American Society for Testing and Materials) and SAE (Society of Automotive engineers) to stay on top of development of engine oils that meet the needs of changing motor oil performance demands.     

In 1987 though, the AAM (Alliance of Automobile Manufacturers) told the API they were not happy with the way API went about approving new motor oils. AAM created a new committee called ILSAC (International Lubricants standardization and Approval Committee)   

ILSAC is made up of nine OEM’s from both North America and Europe and the latest ILSAC standard is called GF-5, an improvement of the former GF-4 mainly aimed at improving motor oil fuel economy benefits and motor oil robustness and protecting complicated new emissions systems.   

As of this writing the API’s most recent categories are “SN” and “SN resource conserving” which apply to gasoline powered  passenger cars and light trucks. API “SN” introduced October 1st, 2010 matches ILSAC GF-5 fairly closely.   

In 2010 though General Motors  introduced its own motor oil specification through the Dexos 1 oil licensing program and consumers driving model year 2011 and newer GM vehicles will have to use a motor oil recommended for Dexos 1 applications.   

Dexos 1 has performance features that exceed those requirements of API SN/ ILSAC GF-5 in some areas and are less strict in others.   

Dexos 1 requires performance to be enhanced over what API SN/ ILSAC GF-5 requires in the following areas; engine sludge protection, volatility, piston cleanliness, turbo charger protection, resistance to oxidative thickening, wear protection, seal compatibility, and corrosion protection.   

Dexos 1 requirements for emissions systems durability, fuel economy and E-85 emulsion retention (use with gasoline containing alcohol) are somewhat less than what API SN/ ILSAC GF-5 require.   

The Dexos 1 licensing program requires motor oil manufactures to pay a licensing fee to General Motors to use the Dexos1 approved logo; essentially making the sale and use of Dexos 1 motor oils a profit center for GM and increasing the cost of the oil.   

Early on the concept GM had for the Dexos 1 licensing program required motor oil manufactures and end-sellers alike to pay a per-quart fee to GM for every bottle of GM Dexos approved oil sold.   

In actual implementation though I believe this has changed to a flat fee per year for manufacturers and end-sellers. Since I’m not privy to GM’s decisions and because the Dexos 1 licensing program is still evolving and has changed more than once since its inception only GM and the manufacturers/ end-sellers who have entered the program know the actual fee’s that add to the retail price of Dexos 1 motor oil.   

While a quite a few motor oil manufactures have started making oil that meets the Dexos 1 specification, at the time of this writing any number of motor oil manufacturers including Valvoline and Amsoil have balked at paying this fee saying it does nothing for the consumer but drive up the cost of the oil and are refusing to join GM’s program.   

The reality for the consumer is that as long as the motor oil you choose says that it is formulated for the Dexos 1 spec you are covered even if the manufacturer has not purchased the right to use the Dexos 1 approved symbol (paid GM’s licensing fee)   

Dan Peterson, Amsoil Inc Vice President of Technical Development stated in a recent interview that while each of the specifications outperforms the other in some certain areas that Amsoil has formulated its full synthetic motor oils to exceed the requirements of API SN, ILSAC GF-5 and GM Dexos 1 in all areas.   

Currently Amsoil OE and XL, 5W/30 full synthetic motor oils meet and exceed Dexos 1 requirements and Amsoil has plans for other such products   

Amsoil Inc. introduced the first full synthetic motor oil to meet American Petroleum Institute requirements in 1972. Today Amsoil is considered the world leader in synthetic motor oils and lubricants.   

By Larry Crider, lubrication specialist  

 Corpus Christi, TX 78411