What does 15w40 mean for engine oil?
2 Answers
15w40 refers to the viscosity of the engine oil, indicating its applicable temperature range from -20 degrees Celsius to 40 degrees Celsius. The 'w' stands for winter-grade oil, and the smaller the number before 'w', the lower the ambient temperature it can be used in. The number after 'w' represents the ambient temperature for non-winter use, with a higher number indicating a higher applicable ambient temperature. Engine oil, also known as motor lubricant, serves to lubricate and reduce friction in the engine, assist in cooling, seal against leaks, prevent rust and corrosion, and provide shock absorption. Engine oil consists of two parts: base oil and additives. The base oil is the main component of the lubricant, determining its basic properties, while additives compensate for and improve the shortcomings of the base oil, giving it new performance characteristics.
I previously encountered an engine oil issue during car maintenance, and I've researched the 15w40 label. It refers to the viscosity grade of the engine oil. The 'W' stands for winter, and the '15' indicates that the oil can still flow well at low temperatures, such as -15°C, making the car easier to start. The '40' means the oil has higher viscosity at high temperatures, like 100°C, protecting the engine and reducing wear. Simply put, this combination of numbers shows the oil's performance in both cold and hot environments, making it suitable for areas with significant seasonal changes. Choosing the right oil depends on the vehicle manual and climate. For example, older cars or engines with high loads are well-suited for 15w40, as it can extend their lifespan. Using the wrong viscosity can lead to difficulties starting in winter or oil leaks damaging the engine in summer. During regular maintenance, I check the dipstick to ensure the oil isn't dirty or low, and I change the oil every 5,000 kilometers or six months for safety. Developing these habits makes driving more reassuring, with less noise and reasonable fuel consumption. Remembering label information helps save money on repairs, and paying attention to details always pays off.
