API classes for diesel engines
From CA to CI-4 PLUS: a description of every “C” class.
- API CI-4 (CI-4 PLUS) Class API CI-4 (2002) and CI-4 PLUS diesel oils: requirements for soot, oxidation and volatility, differences from CH-4 and the place beside CJ-4, CK-4 and CL-4.
- API CH-4 Class API CH-4 diesel oils (1998) for high-speed four-stroke engines: tolerance of high-sulphur fuel, valve protection and replacement of CD, CE, CF-4 and CG-4.
- API CG-4 Class API CG-4 diesel oils (1995) for loaded trucks, buses and tractor units: wear, deposit and soot limits, compatibility with CD, CE, CF-4, modern equivalents.
- API CF-2 (CF-II) Class Oils intended for use in two-stroke diesel engines operating under heavy conditions.
- API CF-4 Class Engine oils for use in four-stroke diesel engines , starting with 1990 model-year engines.
- API CF Class API CF, CF-2 and CF-4 oils (1990–1994) for indirect-injection diesels on high-sulphur fuel: class requirements, replacing CD and what to use instead today.
- API CE Class: Diesel Engines from 1983 Engine oils for use in diesel engines starting with 1983 model-year engines (obsolete class).
- API CD-II Class Engine oils for use in high-output two-stroke diesel engines ( obsolete class ).
- API CD Class Engine oils for high-output diesel engines used in agricultural equipment ( obsolete class ).
- API CC Class Engine oils for diesel engines operated under medium load (obsolete class) .
- API CB Class Engine oils for diesel engines operating under medium load (obsolete class) .
- API CA Class: Diesel Engines API CA is an obsolete class for lightly loaded diesels of the 1940s and 1950s running on quality fuel: protection against ring deposits and bearing corrosion.