What does sg15w40 mean?
1 Answers
sg is the grade identifier of engine oil. 15w40 engine oil represents the grade of the oil, where 15 indicates the lowest temperature in winter that can be used is -20℃. The smaller the number before W, the lower the low-temperature viscosity, the better the low-temperature fluidity, and the lower the applicable minimum temperature. Meanwhile, 40 represents the high-temperature viscosity in summer. The larger the number after W, the higher the applicable maximum temperature. Additional notes on adding engine oil: 1. Higher viscosity does not necessarily mean better engine protection: High-viscosity oil not only adversely affects the vehicle's fuel consumption but also fails to protect the engine effectively. Another function of engine oil is cooling and heat dissipation. When high-viscosity oil is blindly used, the engine's oil cooling performance will inevitably weaken. 2. Engine oils should not be mixed: The additive components in oils from different manufacturers are completely different. The chemical compositions of various additives can vary significantly, not only between different brands but also within different product lines of the same brand. Mixing oils from two brands can cause chemical reactions under the engine's high temperature, such as the formation of flocculent substances in the oil and increased viscosity.
