Engine Oil vs Hydraulic Oil: Can Motor Oil Replace Hydraulic Fluid?

Why You Shouldn’t Replace Hydraulic Fluid with Motor Oil

Some companies try to cut costs by going for universal products or common alternatives. Many experts have heard of the common practice to use engine oils such SAE 10, SAE 20, or SAE 30 with the lowest API ratings as substitutes for hydraulic oils ISO 32, ISO 46, or ISO 68, respectively.

There is no denial that such practice saves some money, at least on the short term! However we need to ask, is it safe? Is it ok to replace hydraulic fluids with engine oils?

Is it safe to replace hydraulic oils with engine oils?

The short answer is no it is not safe. Engine oil and hydraulic oil should not be swapped out for one another. Engine oils and hydraulic fluids are different from each other.
on the short term, engine oil can serve as an alternative that seems safe. However, the damage is done overtime when the parts start to deteriorate and degrade. Using engine oil to replace fluids that aims to act for the purpose of power transmission in the system is a bad idea, a bad costly idea.

Can you mix engine oil with hydraulic oil?

You can mix them and they will work as some experts say. However, what you should ask is what will happen later? When you mix engine oil and hydraulic oil you will have a mixture with reduced or lower viscosity that cannot effectively lubricate moving parts.

If you choose to continue using this blend, sludge is most likely to form on the parts. after a short time, you will start to notice increased vibrations or other signs of corrosion and deterioration in the system.

Why are engine oils incorrect for hydraulic systems?

Engine oils are designed to lubricate engines and cool them down. They can handle pressure to a certain limit, but this is not their main purpose! Early break down is the first and most obvious result of using engine oil in a hydraulic system!

Expect one of two, faster damage to the system due to the increased inefficiency of the engine oil!, or increased costs if you choose to replace the oil that broke down! Damage can appear in various ways and even cause accidents in the workplace.

Why are hydraulic oils incorrect for Engines?

Hydraulic oils are now designed with properties needed in hydraulic systems. Since their objective does not include lubrication, it is possible to experience fast corrosion. Fire is another possibility here. hydraulic oils can ignite faster inside engines due to their lower flash point.

The Difference Between the Hydraulic Oil and Motor Oil

Hydraulic Oil

Hydraulic oil or hydraulic fluids are used to transfer energy into the system. it is simple physics, fluids receive the power, then transfer it to the correct part of the system. According the nature of the system, there can be some additives like Wear Inhibitors to protect the parts from chemical interactions.

Motor Oil

Motor oil is a mixture of base oil and additives that is used to lubricate engine parts. Properties and formulation can vary, however, the main purpose is to protect lubricate the moving part and transmit heat out of the engine. Additive used in motor oils can include detergents to keep them clean, anti-foam or even corrosion Inhibitors.

In Conclusion

As we’ve seen, while there might be instances where engine oil could function temporarily in a hydraulic system, it’s generally not recommended and can lead to serious damage. Using the correct hydraulic fluid, designed with specific properties for hydraulic systems, is crucial for optimal performance and longevity. Armor Lubricants offers a comprehensive range of hydraulic fluids formulated to meet the demanding requirements of various hydraulic applications. Visit Armor Lubricants website to learn more about their products and expert solutions.