What is the difference between engine oil 5w30 and 5w40? Which label is suitable for winter?

1, different high temperature stability

The number after W indicates the kinematic viscosity of engine oil at 100℃. The higher the number, the greater the viscosity, which means it is better and more stable at high temperature, that is, it is less likely to be diluted at high temperature. That is, 5w40 is more stable than 5w30 at high temperature.

2. Use different objects

The viscosity of 5w40 is better than that of 5w30, so it is more suitable for old cars. 5w30 can effectively reduce fuel consumption, make the engine dissipate heat faster and better, and at the same time, it has less noise, so it is suitable for new cars or naturally aspirated engines.

Extended data:

Classification of engine oil and the meaning of numbers and letters in labels

1, and the brands of Xiayou are 20, 30, 40 and 50 respectively.

The larger the number, the greater the viscosity and the higher the applicable maximum temperature.

2. The brands of oil used in winter are: 0W, 5W, 10W, 15W, 20W and 25W.

The symbol w stands for winter. The smaller the number before W, the smaller the low-temperature viscosity, the better the low-temperature fluidity and the lower the applicable minimum temperature.

For example, 0 means it can be used above -35℃, 5 means it can be used above -30℃, and so on, and 25 means it can be used above-10℃.

3. General purpose oil for winter and summer, with brands 5W-20, 5W-30, 5W-40, 5W-50, 10W-20, 10W-30, 10W-40, 10W-50.

The smaller the number representing the winter part, the larger the number representing the summer part, the higher the viscosity and the wider the applicable temperature range.

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