Motor Oil Specifications – The Process of Change

by Thomas F. Glenn

Thomas F. Glenn, President, Petroleum Quality Institute of America

The PQIA has recently fielded many questions about the new API SN Plus Service Category and although some are technical, many others we received are more general and look to understand why specifications change and how the new specifications come about. The short answer why they change can be summed up by pointing to the following drivers:

  • Government regulations mandating improvements in emissions and fuel economy performance
  • Continuous evolution in engine hardware
  • Performance issues with current specifications
  • Interest in higher performance, longer lasting lubricants, and other consumer and OEM based benefits

Although other factors sometimes come into play (i.e. availability of engine parts for testing), government regulations and changes in hardware are the leading reasons new engine oil performance specifications are introduced.

To meet the challenges of these changes, engine manufacturers will sometimes look to additive companies and lubricant manufacturers for fluid solutions. This can result in new specifications and approvals. The process to bring new specifications to the market is complex and varies somewhat between gasoline and diesel engine approvals. This article focuses on the gasoline engine oil approval process.

The Process of Change  

New motor oil specifications are developed through a process that brings together the thoughts and leadership of several organizations with many talented individuals that have expertise in motor oil blending, engine design and manufacturing, additives, base oils, testing, and other areas. The specifications most readers are familiar with in North America are those of the American Petroleum Institute (API) and International Lubricants Standardization and Approval Committee (ILSAC). The process for developing specifications are defined in API 1509; the Engine Oil Licensing Certification System (EOLCS). Embodied in API 1509 is Appendix C for light-duty gasoline claims and Appendix D for heavy-duty diesel claims.

Although it does not capture the details and efforts that industry engages in to develop new specifications, PQIA created a Quick Reference chart to provide an overview of the process.

As shown in the PQIA Quick Reference, the process begins with a request to the API for a new specification. The request can come from any individual, company or association and it must include data and justification to demonstrate a need for a new specification. Original equipment and engine manufacturers are the primary source for such requests.

Whereas the process in North America typically starts with API specifications, it should be noted that OEMs can impose other, sometimes more stringent, requirements. A primary example of this is dexos1™ which is administered by General Motors (GM). Although GM is open to input from other industry stakeholders, they hold the trademark and have the ultimate authority as to the make-up of the dexos® specification, rules around approvals, timing, and licensing requirements. Original Equipment Manufacturer specifications can widely be seen on both gasoline and diesel motor oils. From a commercial viewpoint, key OEM specifications can sometimes become a must-have level of performance that supersedes standard industry specifications. As such, lubricant suppliers must meet these specifications to supply motor oils for use in vehicles where such OEM specifications exist.

Quote6132018In addition, there are other organizations that may influence products in North America, including ACEA (which is the European equivalent of API specifications) and JASO which is widely used in Japan.

Assuming a request for a new specification provides the required information, it’s moved on to the Auto/Oil Advisory Panel (AOAP). The AOAP comprises two groups, typically referred to as “Auto” and “Oil.” The Auto group includes representatives from the Engine Manufacturers Association, Alliance of Automobile Manufacturers, the Society of Automotive Engineers, and other interested parties involved in automobile manufacturing. As expected, the primary interest of this group is that of the car and truck manufacturers.

The second group within the AOAP are referred to as “Oil,” and they bring to bear expertise of lubricant and additive manufacturers and others involved in producing and testing motor oils. Included in this group are major oil companies and independent lubricant manufacturers, lubricant additive manufacturers, and other industry stakeholders.

Representatives from the “Auto” and “Oil” groups evaluate the need for new specifications, and when the need is seen, they develop, debate, and iterate on the testing protocols, specification limits, and other details. In the process, the AOAP interacts with the ASTM’s Passenger Car Engine Oil Classification Panel and independent testing laboratories.

The AOAP produces a draft specification which is then moved on to the Lubricants Group of the API. The Lubricants Group formalizes approvals, drafts user language, establishes the licensing timetable, BOI and VGRA guidelines, and develops licensing requirements.

The next step moves the specification to commercialization which starts with the first use licensing date. Although many lubricant manufacturers have products meeting the new specification already on the fill lines in advance of the first licensing date, claims of meeting the specification cannot be made until the first licensing date set forth by the API. This allows all marketers, large and small, the ability to deliver these products in a similar time frame.

In summary, evolving engine hardware and changes in government regulations for fuel economy and emissions are the primary drivers for new motor oil specifications. Various stakeholders provide the resources to develop these specifications, including Auto (AAM, ILSAC, EMA, and JAMA) which represents the various car and engine manufacturers and Oil (API and ACC) which represents lubricant manufacturers and marketers, base stocks suppliers and additive manufacturers. Select independent testing laboratories are also a key stakeholder and provide the facilities used to test approved lubricants and play a large role in the development and maintenance of engine tests used by industry to support these processes.

The process to develop a new specification requires immense effort on the part of many organizations and talented individuals, intense attention to detail, and millions of dollars invested in formulating and testing. Because of this, the process typically takes a good deal of time and can be a bumpy road along the way. But at the end of the road, new specifications are born and for good reasons which can benefit engine manufacturers, consumers and the environment.

Acronyms Used

AAMAlliance of Automobile ManufacturersILSACInternational Lubricant Standardization and Advisory Committee
ACCAmerican Chemistry CouncilJAMAJapan Automobile Manufacturers Association
ACEAAssociation des Constructeurs Européens d’Automobiles (European automobile manufacturers association)JASOJapanese Automotive Standards Organization
APIAmerican Petroleum InstituteOEMOriginal Equipment Manufacturer
AOAPAuto/Oil Advisory PanelPQIAPetroleum Quality Institute of America
BOIBase Oil InterchangeSAESociety of Automotive Engineers
EMAEngine Manufacturers AssociationSTLESociety of Tribologists and Lubrication Engineers
EOLCSEngine Oil Licensing and Certification SystemVGRAViscosity Grade Read Across
GDIgasoline direct injection  


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