What Do Motor Oil Specifications Represent?
1 Answers
Motor oil specifications consist of two parts: classification and viscosity rating. The oil label typically indicates viscosity and quality. Specifically, the viscosity of lubricating oil is marked with grades such as SAE, which stands for the Society of Automotive Engineers in the United States. The 'W' stands for winter. The smaller the number before 'W', the better the oil's low-temperature fluidity, the lower the usable environmental temperature, and the better the engine protection during cold starts. The number after 'W' (following the horizontal line) indicates the oil's high-temperature resistance. The larger this number, the better the oil's protective performance at high temperatures. The label after the oil classification specifies its viscosity rating. For example, in '15W-40, 5W-40', 'W' stands for winter. The smaller the preceding number, the better the oil's low-temperature fluidity, the lower the usable environmental temperature, and the better the engine protection during cold starts.