What is the viscosity of engine oil and why is it so important?

Viscosity is the ability of an oil to resist flow. In the context of engine oils, viscosity is one of the most critical parameters that determine its performance in various temperature conditions.

The viscosity of the oil is characterized by two main indicators:

• kinematic viscosity at high temperatures (e.g. 100°C);
• dynamic viscosity at low temperatures (for example, -18°C or -25°C), which is usually indicated by the letter “W” (Winter).

The correct viscosity ensures the formation of a sufficient thickness of the oil film between the rubbing parts of the engine. At low temperatures, the oil must