Engine oil plays a vital role in the proper functioning of a car, not only to effectively lubricate the internal parts of the engine, but also to reduce wear and extend engine life. The so-called 5w30 and 5w40 are important information in the oil labeling. So, what exactly do engine oils 5w30 and 5w40 mean?
First of all, the "5w" here represents the winter viscosity of the engine oil, that is, the flow performance of the engine oil in a low temperature environment. The lower the number, the better the flow performance at low temperatures, so "5W" is more suitable for use in cold regions than larger numbers such as "10W". The following numbers "30" and "40" represent the viscosity grade of the oil at high temperatures, that is, the flow properties of the oil in a high temperature environment. The main difference between the two oils is the different viscosity grades in high temperature environments, with 5w30 oil having slightly lower viscosity at high temperatures than 5w40 oil. Therefore, in general, 5W30 is suitable for driving in areas with low temperatures or urban roads with more stable temperatures, while 5W40 is more suitable for use in high-load conditions such as high temperatures, highways or sports cars.
In short, 5w30 and 5w40 are descriptions of the flow properties and viscosity grades of engine oils at different temperatures, and the choice of which engine oil needs to be reasonably considered according to the climatic conditions of the region and the environment in which the vehicle is used. It is hoped that through the introduction of this article, readers can have a clearer understanding of the meaning of these two types of engine oil labels, so as to choose a more suitable engine oil product for their car.