Engine oil viscosity grades describe how thick or thin an oil is and how it flows at different temperatures, helping ensure proper engine lubrication. These grades are defined by the SAE (Society of Automotive Engineers) and are typically shown as numbers like 5W-30 or 10W-40, where the first number followed by “W” (winter) indicates the oil’s flow at low temperatures, and the second ... https://millenniumgroup.ae/engine-oil-viscosity-grades-explained-a-complete-guide/