What does the 'W' in engine oil mean?
1 Answers
Engine oil with 'W' stands for winter oil, indicating that this type of oil can be used normally in winter. Common engine oil grades include 5W30, 5W40, 0W30, and 0W40. The number before 'W' indicates the oil's low-temperature flow performance: 5W means the oil can flow normally at -30 degrees Celsius, while 0W means it can flow normally at -35 degrees Celsius. The number after 'W' represents the oil's high-temperature viscosity, with higher numbers indicating higher viscosity. Engine oil, also known as motor lubricating oil, consists of: 1. Base oil: the main component of lubricating oil, determining its basic properties; 2. Additives: these compensate for and improve any deficiencies in the base oil's performance.