What do the specifications of engine oil represent?
1 Answers
Engine oil specifications represent low-temperature fluidity and kinematic viscosity. The "W" stands for winter, the number before "W" indicates the oil's low-temperature fluidity, and the number after "W" represents kinematic viscosity. Taking 5W40 as an example: 5W means it can withstand external temperatures as low as -30°C; 40 indicates the kinematic viscosity standard at 100°C is 12.5 mm²/s. Engine oil, motor oil, or engine lubricant is a substance enhanced with additives in base oil, primarily containing anti-wear additives, detergents, dispersants, and multi-grade oil viscosity index improvers. Engine oil is used for lubricating internal combustion engines, with its main functions being to reduce friction and wear of moving parts, and to remove sludge and varnish from the engine.