Stable viscosity index

Stable viscosity index means that the oil’s viscosity remains almost unchanged across a wide range of operating temperatures, providing predictable protective action both during cold start and at high engine temperatures. This stability allows maintaining an optimal lubricant film tone, reducing the risk of excessive wear and deposit formation. When selecting a product with this characteristic, you should target use in conditions of sharp temperature fluctuations or prolonged load operation, for example in hybrid, high‑performance or older engines. XENUM oils that have a stable viscosity index are suitable for applications where consistent viscosity is important, including engine, transmission and PAG‑systems.