What does 20W-50 engine oil mean?

[Braylen]

20W50 engine oil refers to the specification of the oil, where 20W indicates that it can start normally at temperatures as low as -15 degrees Celsius; 50 represents the viscosity and flowability of the oil, with a higher number indicating better high-temperature stability. The main functions of engine oil include the following: lubrication and friction reduction; auxiliary cooling; cleaning; sealing and leak prevention; rust and corrosion prevention; and shock absorption. Lubrication and friction reduction: Forms an oil film on the surfaces of two sliding components, preventing friction during operation and ensuring smooth movement. Auxiliary cooling: When the engine operates, it generates high temperatures. When the oil reaches the operating parts, it absorbs heat and carries it away, aiding in heat dissipation. Cleaning: Removes carbon deposits, sludge, and worn metal particles from engine components through circulation, returning them to the oil pan and flushing away contaminants from the working surfaces. Sealing and leak prevention: The oil forms a seal between the piston rings and pistons, reducing gas leakage and preventing external contaminants from entering. Rust and corrosion prevention: The oil adheres to component surfaces, protecting them from contact with water, air, acidic substances, and harmful gases. Shock absorption: When pressure in the engine cylinder rises sharply, suddenly increasing the load on the pistons, piston rings, connecting rods, and crankshaft bearings, the oil's lubrication helps distribute the load, cushioning the impact.