What does the engine oil grade 10w40 mean?
1 Answers
The engine oil grade 10w40 refers to the viscosity of the engine oil being 10w40. The number before the 'w' represents the cold start performance, while the 40 indicates the viscosity characteristics of the oil at high temperatures. Higher viscosity oils (with higher values) may be more suitable for high-speed driving or heavily loaded vehicles. 1. The engine oil grade includes two parts: the classification and the viscosity specification. 2. The number after the 'w' (after the dash) is an indicator of the oil's resistance to high temperatures. A higher number means better protection performance of the oil at high temperatures. 3. The number after the 'w' represents the kinematic viscosity of the oil at 100°C. A higher number indicates higher viscosity.