What does the 'W' in motor oil stand for?

[DeEmiliano]

Motor oil with a 'W' indicates that the oil can be used normally in winter, where 'W' is the abbreviation for 'winter'. Common motor oil grades include: 5w30, 5w40, 0w30, 0w40, etc. The number before the 'W' represents the oil's low-temperature flow performance. 5w means the oil can flow normally at -30 degrees Celsius, while 0w means the oil can flow normally at -35 degrees Celsius. Motor oil, also known as engine lubricant, serves functions such as lubrication and friction reduction, auxiliary cooling, sealing and leak prevention, rust and corrosion protection, and shock absorption. It is often referred to as the 'blood' of a car.

[MacKiara]

Speaking of the 'W' in motor oil grades, let me explain it in detail. This 'W' is actually an abbreviation for 'Winter' in English, meaning winter. It mainly reflects the fluidity of the oil in low-temperature environments. For example, in the commonly seen 5W-30, the number before the 'W' represents the low-temperature viscosity grade. The smaller the number, the less likely the oil is to solidify in cold weather, providing better protection during cold starts. The number after the 'W' is the high-temperature viscosity grade, where a larger number indicates that the oil can maintain sufficient oil film strength even at high temperatures. Therefore, when choosing motor oil, you need to consider your local climate conditions. In areas with particularly cold winters, you should choose an oil with a smaller number before the 'W'.

[DiJasmine]

I remember when I first bought my car, I didn't understand what the W on the engine oil meant. Later, after checking some information, I realized that W stands for Winter, indicating winter performance. For example, in 5W-40 oil, the 5 represents low-temperature fluidity, and the 40 after W is the high-temperature viscosity. If you live in a place with very cold winters, you should choose oil with good low-temperature fluidity, meaning a smaller number before W, so starting the car in the morning won't be too difficult. I now always choose oil based on this standard, and it really works well.

[VonElias]

The 'W' marking on the engine oil bottle actually tells you how the oil performs in winter. 'W' stands for 'Winter' in English. Here in the north where winter temperatures drop below -20°C, we need to use oil that starts with 0W, so the car starts right up in the morning. If you use the wrong oil, your car will suffer in winter. Summer isn't a big deal, the number after the 'W' is key, but in winter, you still need to pay attention to the number before the 'W'.

[IsabelaAnn]

Last time my car had trouble starting on a cold winter morning, the mechanic said I was using the wrong engine oil. Turns out the 10W-40 oil I used was too thick. He told me the 'W' in oil stands for Winter, and the smaller the number before W, the more suitable it is for cold regions. Later I switched to 5W-30, and now it starts instantly even on the coldest days. So never underestimate that 'W' in oil specifications - it directly determines whether your car can start properly in winter.