Engine oil viscosity grades indicate how thick or thin the oil is at different temperatures, helping ensure proper lubrication under varying engine conditions. The grade is typically expressed in a format like "5W-30," where the number before the "W" (winter) represents the oil's flow at cold temperatures, and the number after indicates its viscosity at operating temperature. Lower nu... https://millenniumgroup.ae/engine-oil-viscosity-grades-explained-a-complete-guide/