The initial filling of new construction machines with lubricants – and thus also the quality of the specified hydraulic fluids – is usually very good. They are often enriched with additives for protection against corrosion, oxidation or wear and tear. However, a viscosity improver in the fluid is not always a given. This would have a positive impact on the agility and efficiency of the entire construction machine.
Evonik, owner and licensor of DYNAVIS®, a formulation for improving the viscosity of hydraulic fluids, has already proven its relevant fuel-saving potential for many years in practical tests. A double test at Xaver Lutzenberger GmbH was intended to confirm this once again.
Lutzenberger is an established name far beyond the entire Southern German region. Over 300 employees cover a wide range of activities from building construction and structural engineering via canal building and water pipeline construction to civil engineering and road construction. When Lutzenberger was encouraged by its oil supplier to perform a consumption test, the fleet manager was immediately prepared to do so.
Avia BANTLEON: Lubricant specialist for construction machines with new hydraulic fluid
With over 20 mineral oil-based hydraulic fluids, Avia is highly diversified. Then why is there a need for yet another hydraulic fluid formulated with DYNAVIS® technology? Rainer Janz, Head of Product and Quality Management at Avia BANTLEON AVILUB FLUID DYNA 46, had this to say: “It is an efficiency-optimized fluid that can display its strengths, especially under high loads. And it provides particularly good cold start behavior.”
Test with a hydraulic excavator
The hydraulic tank of a Liebherr LH 934C was filled with 550 liters of AVILUB FLUID DYNA 46. The machine had been filled previously with a conventional hydraulic fluid of viscosity class 68. The excavator has two hydraulic pump systems, one for equipment and chassis, and the other for the slewing gear. In this case, it was used for the construction of a bypass, i.e. for lifting and loading material onto a truck. The test started on Wednesday, November 2, 2016, and took 14 working days or 107 operating hours. A conclusion was drawn on Tuesday, November 19, 2016.
Two liters of fuel saved per hour
With the old hydraulic fluid, the excavator consumed 7,056 liters of diesel within 290 operating hours, thus 24.33 liters per hour. After changing the oil to AVILUB FLUID DYNA 46, the same machine consumed a total of 2,384 liters of diesel within 107 operating hours. This resulted in an average of 22.28 liters per hour. AVILUB DYNA 46 ultimately saved more than 2 liters of fuel per operating hour, thus achieving a 9.2% reduction in consumption.
Seizing the opportunity to perform a second test
The second test at Lutzenberger involved the demolition of a two-lane concrete clamping bridge. The conditions were excellent: Two identical hydraulic excavators with the same accessory equipment and a tight schedule. A weekend had to be sufficient to complete the order so as not to affect the commuter traffic.
The excavators operated non-stop from Friday, March 24 to Sunday March 26, 2017. The test involved two Liebherr R 934 Litronic crawler excavators of the same year of manufacture 2008, one with 13,100 operating hours on the meter, and the other with 13,000 hours. While one excavator was filled with a conventional hydraulic fluid with a viscosity grade of 68, the oil of the other excavator was changed to AVILUB FLUID DYNA 46. The accessory equipment was a Rammer hydraulic hammer.
The conclusion: The machine with the conventional hydraulic fluid exhibited an average consumption of 19.96 liters of diesel per operating hour, while the excavator with the DYNAVIS® formulated AVILUB FLUID DYNA 46 consumed only 18.51 liters per hour on average. Once again, the hydraulic fluid formulated with DYNAVIS® technology was able to impress in terms of its machine efficiency. The difference of 1.45 liters corresponds to a percentage saving of 7.27% with the same demolition performance in the measured period.
One of the “secrets” underlying the increase in efficiency due to a viscosity-optimized fluid such as AVILUB FLUID DYNA 46 was the viscosity class: The previously replaced fluid had VC 68 and was thus slightly more viscous than the AVILUB FLUID DYNA 46 fluid formulated with DYNAVIS® technology. This is possible without any risk because it develops a higher viscosity due to its formulation if necessary, thus ensuring lubrication and protection of the hydraulic system. When subject to heat and pressure, AVILUB transports more pump energy because it reaches the target site with less leakage loss. At normal temperatures, however, it flows more readily and reduces resistance to the pump. It is ultimately quicker and easier to set in motion during cold starts and can even be started at lower temperatures. This improves the throttle response of the cold machine and also presumably reduces wear and tear. The corresponding data is currently determined by Evonik.
Long-term gain in efficiency through shear stability
The art of the DYNAVIS® formulation includes, among other things, the customizing of the molecular length and quantity ratio of the additive to the application and the base oils used. It is only then that the effect remains constant over the entire life cycle of the hydraulic fluid, even with a permanently high mechanical load. Having developed this technology, Evonik is likely to have mastered this art.
Due to the shear stability, the savings effect with AVILUB FLUID DYNA 46 is not just a short-term effect, but remains constant.
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