Oil quality and performance level
Generally, the certification of engine oil quality can be classified into 3 major systems: API (American Petroleum Institute), European Automobile Manufacturers' Association (ACEA), and the standards of each car manufacturer. The specifications and grades of each certification are as follows:
1.API specification and grade: Before describing the meaning of these symbols, we will introduce the American Petroleum Institute (API), the most popular engine oil quality certification organization. API forms the Engine Oil Licensing and Certification System (EOLCS) with other organizations to provide quality indicators of classification and symbols for cars and diesel cars. The symbol demonstrates that the oil meets the performance requirements set up by global car/engine/lubricant manufacturers. For example: In a symbol of SN/CH-4, “S” means (general) gasoline engine, “C” means (commercial) diesel engine and the second code refers to the quality grade of engine oil. Generally, a letter with a later order means a higher and newer engine oil quality. Products for gasoline engines have developed to the SN grade.
Currently, there are over 500 engine oil manufacturers who have acquired API certification in the world. These brands accept API’s intermittent inspections to ensure their oil quality meets the API standards. Products certified by API all have this “Symbol Donut” (Fig.3). Of course, there are also packages showing the API grade only.
2.ACEA engine test and quality grade in European engine oil specifications. The grade was originally established by the CCMC (Comité de Constructeursd’Automobiles du Marche Commun). “G” means gasoline engine oil, “D” for diesel engine oil and “PD” for diesel passenger vehicle engine oil. However, the European Automobile Manufacturers' Association (ACEA) replaced the CCMC in 1995 and modified the original CCMC quality grades in January 1, 1996. In ACEA specifications, “A” means gasoline engine oil, “B” for light-duty diesel engine oil and “E” for heavy-duty diesel engine oil. Generally speaking, a larger number represents an oil with higher performance requirements. For example, G5 has a higher grade than G4 and E3-96 higher than E1-96 (96 means the specifications released in 1996).
3.Specification of major car manufacturers: Major car manufacturers such as VOLKSWAGEN(VW), SAAB, BMW, PORSHE, MERCEDES-BENZ and PEUGEOT set up a stricter specifications for their engines. Many large engine oil manufacturers will pay for the accreditation of car manufacturers and mark it on the bottle to prove their technical capabilities, as well as enable customers to distinguish them from generic engine oils.