Posts Tagged: Viscosity Index Improver

Viscosity Index Improver: What it is and how it works

Understanding Viscosity Index Improvers and Their Role in Engine Performance Viscosity Index Improvers (VIIs) are special polymer additives used in multi-grade engine oils to enhance the oil’s ability to maintain a consistent viscosity across a wide range of temperatures. These polymers are long-chain molecules that expand when heated and contract when cooled. This expansion and contraction help the oil maintain its viscosity, providing optimal lubrication under varying operating conditions. VIIs are typically added to base oils to create multi-grade oils, which are designed to perform well in both cold and … Read More