This specification covers engine oils for light-duty and heavy-duty internal combustion engines used under a variety of operating conditions in automobiles, trucks, vans, buses, and off-highway farm, industrial, and construction equipment. Automotive engine oils are classified in three general arrangements: S, C, and Energy Conserving. These arrangements are further divided into categories with performance measured as follows: SH, SJ, SL, SM, CF-4, CF, CF-2, CG-4, CH-4, CI-4, CJ-4, Energy Conserving associated with SJ, and Energy Conserving associated with SL. Different bench and chemical tests shall be performed to help evaluate some aspects of engine oil performance.

1.1 This specification covers engine oils for light-duty and heavy-duty internal combustion engines used under a variety of operating conditions in automobiles, trucks, vans, buses, and off-highway farm, industrial, and construction equipment.

1.2 This specification is not intended to cover engine oil applications such as outboard motors, snowmobiles, lawn mowers, motorcycles, railroad locomotives, or oceangoing vessels.

1.3 This specification is based on engine test results that generally have been correlated with results obtained on reference oils in actual service engines operating with gasoline or diesel fuel. As it pertains to the API SL engine oil category, it is based on engine test results that generally have been correlated with results obtained on reference oils run in gasoline engine Sequence Tests that defined engine oil categories prior to 2000. It should be recognized that not all aspects of engine oil performance are evaluated by the engine tests in this specification. In addition, when assessing oil performance, it is desirable that the oil be evaluated under actual operating conditions.

1.4 This specification includes bench and chemical tests that help evaluate some aspects of engine oil performance not covered by the engine tests in this specification.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5.1 Exceptions—The roller follower shaft wear in Test Method D5966 is in mils. Appendix X2 descriptions are verbatim API language, which contains a few non-SI units.