2 Realistic Reasons for Using Multigrade Hydraulic Fluid Getting more efficiency from your hydraulic system through the use of multigrade hydraulic fluids makes sense, especially when it comes to the rising financial expense of all engineering overheads. We recently read a case study where a piece of hydraulic equipment was shipped to an industrial site with the wrong hydraulic oil in place. Unfortunately this ended up causing terrible damage with 4 pumps failing, at a cost of £15,000 each, 3 swing motors failing, 2 motor failures of track drives. Altogether the maintenance and downtime resulted in a cost of £147,832 all within the first 24 months of service. Although you might not be responsible for hydraulic equipment of this nature, the rules should stay the same. Using the wrong oil can result in bad performance and damage. Why Hydraulic Fluid is Different from Other Lubricants Knowing that hydraulic fluid is not the same as oil helps. It’s not just a lubricant but it’s a medium of power transmission. Having a double role is what makes it special. For it to be effective and dependable, it’s important for hydraulic oil to be similar in properties to lubes. It needs to have resistance against foaming and air release, stability for thermal, hydrolytic and oxidative purposes and to also be filterable. It should also inhibit rust and corrosion in addition to being viscose enough to lubricate – working together these properties are vital to delivering the maximum lifespan of hydraulic components. The Benefits of Multigrade Fluid Bulk modulus is resistance to compression and is something that is inherent to base oil. It’s not something that can be improved upon through the use of additives. However, using synthetics or polymers can improve viscosity index. In fact, the engine oils of the 1940s used viscosity index improvers. It’s a common technology for multigrade oils to have high viscosity index for a range of applications, including use as automatic transmission fluid. However, these viscosity index improvers are not something that remain stable when put under the challenging environment of the hydraulic system. However, there are some hydraulic oils that have been developed with viscosity index of 150 to 200 range that are stable. Using multigrade hydraulic oil to maintain viscosity is one of the major reasons why it’s used. It makes seasonal oil changes unnecessary. It also keeps it’s resistance to enable maximum power transfer, and make machine cycle times faster for increased productivity, therefore reducing electricity or fuel consumption. Using multigrade or high viscosity index oil means that the power transmission of a hydraulic system is retained over a broader operating temperature range. You might think that this is similar to adding an automatic tensioner on the V belt drive in order to maintain the optimal power transfer output and to some degree, you’d be right. However, adding a tensioner could cost you up to £150, whilst the oil is likely to give you better return on the investment. It will save you costs on maintenance in the longer term in addition to reducing power usage whilst maintaining efficient power transmission. Although multigrade oil might be more costly than monograde, by analysing what the return on investment is, you may evaluable that the benefits are greater than using a monograde. Your evaluation should include savings made from improving machine performance. Although we don’t claim to be the top engineers in the country, we do know what we’re talking about when it comes to hydraulic systems. That’s why we are recognised as the nation’s experts in hydraulic power packs for both mobile and industrial applications. Our team gained ISO9001 accreditation back in 2013, and our culture is based on advancing our product through the application of our deep hydraulic system knowledge and experience. We are also heavily focused on delivering customer satisfaction through both our product and our service. If you want a no obligation chat about your hydraulic system requirements, feel free to give us a call. We’re here to help and are happy to do so. Some people even say we’re friendly!