Viscosity Index (VI) Improvers

Viscosity Index (VI) improvers are additives used in engine oils to help maintain consistent viscosity across a wide temperature range. Essentially, they help the oil stay thick enough to protect the engine at cold start-up and thin enough to flow easily at high operating temperatures. These additives are usually long-chain polymers that expand when heated, increasing the oil's resistance to thinning. This stability ensures efficient lubrication, enhances engine performance, and extends oil life, especially under varying temperature conditions. VI improvers help ensure your engine runs smoothly whether it's cold outside or the engine is hot.