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), the International Lubricant Specification Advisory 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 thus 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, or for which the Category Life Oversight Group has established equivalencies between unavailable tests and newer, available tests; (b) which ASTM or the test developer monitors precision for all tests; and (c) which are available for licensing by API EOLCS at time of writing. 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 Annex C. New API “C” categories are added using the procedure defined in API 1509 Annex D. New API “S” categories are added by the API Lubricants Group.