API is the product mark of the " American Petroleum Institute " (commonly known as donuts).
Its primary purpose is to develop standardized working standards for the safety, reliability and interchangeability of oil and gas extraction.
It is also an accredited standards development organization of the American National Standards Institute.
The standards set by API are used in many countries for oil, natural gas chemical and extraction machinery
technologies. Because the process is standardized and difficult to pass, products with the API certification mark
are widely considered to be of high quality.
The API grade is mainly based on the operational performance of the engine oil, whether it meets the environmental
requirements, strict standard process screening in all aspects was finally passed, and now it has reached the SP level.