Efficiency Benefits - Hydraulic Applications

Lubrizol’s Asteric VMs Enable High VI Hydraulic Fluids that Deliver Higher Efficiency and More Productivity

Mobile equipment end users are demanding hydraulic fluids that provide greater efficiency and productivity while still protecting system components. Using a high VI hydraulic fluid is one approach to achieving this performance.

The Impact of Viscosity Index

Using higher viscosity index (VI) fluids represents an excellent approach to increasing the efficiency, productivity, and performance of hydraulic systems, especially in outdoor mobile equipment. Higher VI fluids are more fluid at low and normal operating temperatures, so hydraulic equipment is ready to work faster after cold start up and the fluid reaches critical parts more quickly to protect against premature wear. High VI fluids also retain viscosity better at high temperatures. This means they protect better in severe service to insure component durability while maintaining operating efficiency.

There are two elements to consider in evaluating overall hydraulic system efficiency: volumetric and mechanical efficiencies. Volumetric efficiency is related to the flow losses within the hydraulic pump or other components due to internal leakage. Mechanical efficiency is related to the viscous drag and the amount of energy required to generate flow. There is an optimum viscosity range where hydraulic systems operate at maximum effectiveness. 

In the classical understanding of hydraulic efficiency, overall system efficiency is a function of viscosity. Volumetric efficiency increases with increasing viscosity. Mechanical efficiency decreases when increasing viscosity. The overall efficiency goes through a maximum.

High VI hydraulic fluids change viscosity less as temperature changes. This is a significant advantage as it means they retain viscosity at high temperatures to maintain pump volumetric output and flow more easily at cold temperatures to reduce viscous drag and pumping losses. The high VI fluid’s viscosity remains in the “efficient” zone across a wider temperature range.

High VI fluids are more efficient over a wider temperature range.

Lubrizol demonstrated this performance in a real world trial. We operated a Komatsu 320 wheel loader in a simulated loading and conveyance cycle to compare the factory fill fluid (SAE 10W-30 CD quality engine oil) to an ISO 46 high VI fluid having 200 VI.   

The high VI fluid containing Lubrizol’s Asteric VM allowed the unit to operate 9% faster on average while using about 4% less fuel per work cycle on average. Both fluids had viscosity at 100°C of 10.3 cSt. This means the high VI fluid containing Asteric VM was both more efficient and more productive than the factory fill oil.

The high VI fluid containing Asteric VM allows the unit to perform approximately 9% faster while using approximately 4% less fuel per work cycle, on average.

In summary, high VI fluids containing Lubrizol’s Asteric VMs demonstrated better efficiency and fuel economy in an actual hydraulic application.