This SAE Standard outlines the engine oil performance categories and classifications developed through the efforts of the Alliance of Automobile Manufacturers (Alliance), American Petroleum Institute (API), the American Society for Testing and Materials (ASTM), the Engine Manufacturers Association (EMA), International Lubricant Standardization and Approval Committee (ILSAC) and SAE. The verbal descriptions by API and ASTM, along with prescribed test methods and limits are shown for active categories in Table 1 and obsolete categories in Table A1. Appendix A is a historical documentation of the obsolete categories.
For purposes of this document, active categories are defined as those (a) for which the required test equipment and test support materials, including reference engine oils and reference fuels, are readily available, (b) for which ASTM or the test developer monitors precision for all tests, and (c) which are currently available for licensing by API EOLCS.
The current processes for initiating new classifications were developed through the cooperative efforts of the Alliance, API, ASTM, EMA, ILSAC, and SAE. New ILSAC classifications are developed using the procedure defined in API 1509 Appendix C. New API "C" categories are added using the procedure defined in API 1509 Appendix D. New API "S" categories are added by the API Lubricants Committee.
The API Engine Oil License and Classification System (EOLCS) for gasoline and diesel engine oils and the International Lubricants Standardization and Approval Committee (ILSAC) Standards for Passenger Car Engine Oils are incorporated within the API EOLCS together with the SAE J300 Engine Oil Viscosity Classification and form the most widely used referenced systems for automotive crankcase oils. While SAE J300 classifies engine oils by their viscometric or rheological characteristics, SAE J183 provides a comprehensive background on the API and companion ILSAC classifications that also address other characteristics of engine oils such as wear and oxidation resistance to ensure appropriate lubricant protection and performance for the automotive engine.
Such a collection of API and ILSAC classifications provides a gathering of the laboratory and engine tests required to define and meet these classifications. This information is believed highly important to those interested in the identification and comparison of the critical factors important to each classification as well as their eventual utilization. Perhaps of more importance is the clarification of differences among API and ILSAC classifications for those oils identified only by the API 'doughnut', those identified by the ILSAC 'starburst', and those engine oils carrying both trademarks.
This J183 Standard also includes explanations of the tests used in evaluating and categorizing engine oils as well as information about the background of their development and significance.
Essentially, the SAE J183 Standard is for reference and education on the complexities and relationships among automotive engine oil classifications.