SAE represents the Society of Automotive Engineers International. The 10w40 stands for the SAE standard viscosity value of the oil, which is a multi-grade oil suitable for both winter and summer use.
This viscosity value indicates that the oil is a multi-grade oil, with “W” standing for “Winter”. The number before “W” represents the oil’s flowability at low temperatures, with a lower number indicating better starting performance in cold weather. The number after “W” represents the oil’s stability at high temperatures.
