What is the difference between 0w30 and 0w40?

[HaileyAnn]

Here are the differences between 0w30 and 0w40: 1. Different viscosity: The smaller the number before the W in the engine oil grade, the lower the low-temperature viscosity. The larger the number after the W, the higher the viscosity at 100°C. Generally, engine oil used in winter will have the letter W, which stands for Winter. The smaller the number before W, the lower the low-temperature viscosity, the better the low-temperature fluidity, and the lower the applicable minimum temperature. For example, 0W has better low-temperature fluidity than 5W. If there is a number after W, such as 30 or 40, it represents the viscosity of the engine oil at 100°C. 2. Different applicable engine types: Due to the difference in viscosity, these two types of engine oil are suitable for different engine types. In terms of low-temperature fluidity, these two engine oils are similar, but the viscosity of 0w40 is higher than that of 0w30. Therefore, in terms of engine usage, 0w40 is more suitable for turbocharged engines, while 0w30 performs better in naturally aspirated engines.