15W40 is a multigrade engine oil rating that describes how the oil performs at different temperatures, ensuring reliable lubrication in both cold starts and high-temperature conditions. The “15W” refers to the oil’s viscosity in winter (W), meaning it flows well enough at low temperatures to protect the engine during startup. The “40” indicates the oil’s viscosity at operating tempera... https://millenniumgroup.ae/what-does-15w40-mean/