What are the classifications of engine oil?
1 Answers
Engine oil is divided into mineral oil, semi-synthetic oil, and fully synthetic oil. In addition to these major categories, engine oil is also classified by operating temperature. The commonly used antifreeze index is 5W, while the high-temperature index mostly ranges between 30-40, which can basically meet the needs of most engines. Mineral oil is extracted from minerals and is relatively viscous. It was widely used in the past but is gradually being replaced by synthetic oil. Synthetic oil is artificially formulated through chemical processes. Fully synthetic oil offers the best performance. If your vehicle has a turbocharged (T) engine, it is recommended to use fully synthetic oil due to its excellent smoothness and cleanliness, as well as a longer replacement interval. Semi-synthetic oil is a blend of synthetic and mineral oil, offering performance between the two, with a moderate price and replacement interval. For ordinary naturally aspirated engines, semi-synthetic oil can be used. In addition to the major categories, engine oil is also classified by operating temperature. When selecting engine oil, you will notice that each type has a rating, such as 5W-40 or 0W-30. The number before the "W" represents the antifreeze index, indicating the lowest temperature at which the oil can function normally. Generally, 5W-rated oil is sufficient unless you are in extremely cold northern regions. The number after the "W" indicates the oil's viscosity in high-temperature environments—the higher the number, the greater the viscosity.
