Should I Use 5W30 or 5W40 in Winter

[DylanLee]

Oil grades W30 and W40 refer to the viscosity of the oil, with higher numbers indicating greater viscosity. In practical use, W30 oil has lower viscosity and better fluidity, while W40 oil is thicker and has relatively poorer fluidity. Therefore, in low winter temperatures, it is advisable to use W40-grade oil with better fluidity, which makes it easier to start the car. Relevant information about engine oil is as follows: 1. Introduction: Engine oil, also known as engine lubricant (English name: Engine-oil), has a density of approximately 0.91×10³ (kg/m³). It serves to lubricate and reduce friction, assist in cooling, seal against leaks, prevent rust and corrosion, and act as a shock absorber for the engine. It is often referred to as the 'blood' of the car. 2. Composition: Engine oil consists of 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, imparting new characteristics, making them an essential part of the lubricant.