The viscosity index describes how much the viscosity changes with temperature. A high viscosity index means that the oil maintains a consistent viscosity at both low and high temperatures, which is desirable in many machine systems.
The index is calculated based on viscosity measurements at 40℃ and 100℃. The less the viscosity varies, the higher the index.
The customer receives information about the oil's stability during temperature fluctuations – an important basis for decision-making for equipment exposed to varying operating conditions.