API stands for American Petroleum Institute and is a conventional US measure for density. The API grade provides information on the chemical composition and thus on the quality of oil.
In general, the API value of an oil consists of 2 parts:
Example: API SJ/CF
S = stands for "Service Oils" - use in petrol engines.
J = provides information on the quality of the oil when used in petrol engines.
C = for "Commercial Oils"- use in diesel engines.
F = provides information on the quality of the oil when used in diesel engines.
The following qualities haven been classified according to API up to the present:
API classifications for Otto engines
Class: Status: Application / Requirements
- SA: no longer valid: Regular motor oils possibly with Stockpunktverbesserer and / or foam inhibitors.
- SB: no longer valid: Wenigbeanspruchte petrol engine oils with additives to aging, corrosion and wear. Since 1930.
- SC: No longer valid: Otto engine oils which are exposed to average operating conditions. With active ingredients to corking, cold sludge, aging, corrosion and wear. From 1964 - 1971st
- SD: no longer valid: Otto engine oils with higher operating conditions than API-SC. Of 1968 - 1971st
- SE: no longer valid: Motor Oils for very high standards and highly contaminated Ottomo motors (stop-and-go traffic). From 1971 - 1979.
- SF: no longer valid: Motor Oils for very high standards and highly contaminated petrol engines (Stop-and-go traffic). From 1980 - 1987. Exceeds API-SE in oxidation stability, wear protection and Schlammtragevermögen.
- SG: obsolete: Motor Oils with the highest requirements, special tests for oxidation stability and sludge formation. From 1987 - 1993.
- SH: date: Meets largely API SG, concerning additional requirements HTHS, evaporation, filtration, foam behavior and flash point. From 1993 - 1996.
- SJ: current: succeeded to SPI-SH. Stricter requirements for evaporation loss.
- SL: news: Once again, more stringent requirements regarding oil consumption, Motorauberkeit and aging behavior. For extended Ölwechselintervale. introduced in 2001.
- SM: current: Once again tightened requirements for oxidation stability, engine cleanliness, wear protection, aging behavior and performance at low temperature
API classifications for diesel engines
Class: Status: Application / Requirements
- CA: no longer valid: For easy claimed gasoline and diesel engines operated on low sulfur fuels. Suitable for motors up to the 50.
- CB: No longer valid: for mild to mittelbelastete gasoline and diesel self-priming, which are operated with sulfur-rich fuels. Engines 1949. Provide protection against high temperature deposits and bearing corrosion.
- CC: No longer valid: For gasoline and diesel engines, the moderate to severe operating conditions are exposed. Provide protection against cold sludge, corrosion and high temperature deposits. 1961.
- CD: obsolete: motor oils for heavily loaded diesel engines with and without charge. introduced 1955th
- Outdated CD II:: Meets API CD met the additional requirements of two-stroke diesel engines Increased protection against wear and deposits. introduced 1987th
- CE: obsolete: motor oils for heavily loaded and high-speed diesel engines with and without charge, which are often highly variable loads. Increased protection against Öleindickung and wear, improved piston cleanliness. instead of API CC and CD can be used. introduced 1987th
- CF: News: Replaced from 1994 API CD. For highly supercharged diesel engines. High ash. Suitable for diesel fuels with sulfur content> 0.5%.
- CF-2: current: Only for two-stroke diesel engines. Replaced from 1994 API-CD II
- CF-4: obsolete: For fast and supercharged four-stroke diesel engines. Covers the requirements of API CD, CE, supplemented by requirements for oil consumption and piston cleanliness. introduced 1990th
- CG-4: current: For heavy-duty truck engines. Take into account EPA emission boundaries after 1994. Detergiereigenschaften better and better foaming properties as API CF-4. Can instead of API CD, CE and CF 4 are used. introduced in 1995.
- CH-4: current: designed for high-revving four-stroke engines, the stringent new Abgasverordungen. Comparable with ACEA E5, lower Aschegahalt. For sulfur content to 0.5%. Can instead of API CD, CE, CF-4, CG-4 and can be used. introduced in 1998.
- CI-4: current: For high-revving four-stroke engines, the emissions laws in the future only can fulfill using exhaust gas recirculation. For sulfur content to 0.5%. Can instead of API CD, CE, CF-4, CG-4 and CH 4 can be used. introduced in 2002.
- CJ-4: current: For high-revving four-stroke engines to meet the required starting in 2007, "highway emissions standards. Especially for vehicles with particulate filter systems and sulfur contents up to 0.0015%. introduced in 2006
API classifications for Bikes
Class: Application / Requirements
- TA (TSC-1): for mopeds
- TB (TSC-2): For scooters and motorcycles
- TC (TSC-3): For the high-speed engines
API - Specifications for outboard after NMMA
(National Marine Manufacturers Association)
- TC-W: no longer valid
- TCW: no longer valid
- TC-WII: no longer valid
- NMMA TC-W3: 1996 current specification