What is the difference between 0W-40 and 5W-40 engine oil?

[MacJulianna]

The only difference lies in their low-temperature resistance: The 5W in 5W-40 oil indicates an external low-temperature resistance of -30°C, while the 0W in 0W-40 oil represents an external low-temperature resistance of -35°C. Below are detailed explanations about automotive engine oil: 1. Overview: Engine oil, also known as engine lubricant (Engine-oil), has a density of approximately 0.91×10³ (kg/m³). It serves functions such as lubrication and wear reduction, auxiliary cooling, sealing and leakage prevention, rust and corrosion protection, as well as shock absorption. 2. Composition: Engine oil consists of two main components—base oil and additives. The base oil is the primary constituent of lubricants, determining their fundamental properties. Additives compensate for and enhance the performance shortcomings of the base oil, imparting new characteristics, making them a crucial component of lubricants.