In the 1920s, hydraulic systems faced a fundamental problem: oils became too thick in winter and too thin in summer, causing equipment failures and inefficiency. The viscosity index (VI) was invented to measure how much an oil's thickness changes with temperature. Early mineral oils had VI values around 95-100, which wasn't enough for demanding applications.
The breakthrough came with high viscosity index (HVI) formulations that maintained consistent flow characteristics across extreme temperature swings. This meant hydraulic systems could start reliably in freezing conditions yet maintain proper film strength during hot operation—critical for construction equipment, agricultural machinery, and industrial systems operating outdoors.
HVI technology essentially gave hydraulic systems year-round reliability without seasonal oil changes, revolutionizing mobile hydraulics and heavy-duty applications.
Modern formulations like HYDRAULIC OIL HV 15 continue this HVI tradition for heavy-duty hydraulic systems requiring consistent performance across varying conditions.
