what is sae oil

SAE stands for Society of Automotive Engineers, and it is a numerical classification system that defines the viscosity or thickness of oil. The SAE number, also known as the viscosity rating or viscosity grade, is a code that grades motor oils by their viscosity characteristics. The SAE viscosity grade is written on the bottle of motor oil right before the viscosity grade. The SAE viscosity grade is a two-number code separated by a hyphen, such as 5W-30. The first number followed by a W refers to the viscosity grade in cold temperatures, and the second number refers to the viscosity in warm temperatures measured at 100ºC. A lower SAE W number indicates that the oil will flow better, have better cold starts, and lower engine wear. The higher the SAE grade, the higher the viscosity and denser the lubricating film, which is necessary in warm temperatures to protect the mechanical pieces in contact. However, excessive viscosity at high temperatures could cause more internal friction and poorer engine performance and consumption.