What does the engine oil specification 10w40 mean?
2 Answers
Engine oil specification 10w40 refers to the oil viscosity. The number before the 'w' represents the cold start performance - the smaller the number, the better the oil's low-temperature fluidity. The 'w' indicates that the oil can be used in winter. The number after the 'w' represents the kinematic viscosity of the oil - the higher the value, the higher the viscosity. The functions of engine oil are: 1. To reduce friction and high temperatures; 2. To cool and lower temperature; 3. To clean and remove contaminants; 4. To cushion and absorb shocks; 5. To prevent rust and corrosion. Engine oil, also known as motor lubricant, consists of: 1. Base oil: the main component of lubricating oil, determining the fundamental properties of the lubricant; 2. Additives: to compensate for and improve the deficiencies in the performance of the base oil.
I have worked in an auto repair shop for ten years and often help customers understand oil specifications. 10W40 means this oil is suitable for various temperature conditions. The 10W indicates that in cold winter conditions with a minimum temperature of around -25°C, the engine starts easily with good fluidity, preventing engine seizure. The 40 means that in hot summer conditions, such as at 100°C, the oil maintains a higher viscosity, effectively lubricating and protecting engine components from wear. I have used various oil specifications, and 10W40 is truly a worry-free choice, especially suitable for the seasonal changes in most parts of China, eliminating the hassle of changing oil in spring and autumn. I recommend following the owner's manual for the replacement frequency, typically every 8,000 to 10,000 kilometers or every six months. Choosing reputable brands like Shell or Mobil can extend engine life and reduce maintenance costs. During maintenance, always check the oil dipstick to ensure the oil level is normal and avoid leaks or excessive oxidation.
