Is Jack Oil the Same as Hydraulic Oil? (Which One Should Use)

Is jack oil the same as hydraulic oil

Hydraulic oil is a fluid that is used in hydraulic jacks to hoist/raise/lift heavy objects like motor vehicles with a small applied force. A hydraulic jack is a device often used in automobile workshops for lifting vehicles as well as in railway works, the hydropower industry, the construction industry, and also in the aviation industry. Generally, a jack can be mechanical, hydraulic, electrical, or pneumatic/air-filled. However, in this case study, we will be exploring answer to this common question. Is jack oil the same as hydraulic oil? Let’s get started.

What is Jack Oil?

Jack oil is a substance used in hydraulic jacks to lift any heavy object with less amount of force. It is a heavy-duty, non-corrosive lubricant widely used in the automobile industry.

The arrangement of lifting bulky objects by utilizing the power/potential of fluids for operation is identified as a hydraulic jack.

This mechanism needs a piston and fluid. The efficiency of the hydraulic jack depends on the properties of the jack oil used.

When selecting particular jack oil, we must consider some important qualities of it. Some of them are viscosity, filterability, hydraulic stability, thermal stability, non-corrosive nature so on.

The ideal fluid must have the correct viscosity because it is the major aspect that can directly affect the performance of the hydraulic jack.

Incorrect viscosity selection will lead to poor performance and lower the service life of the jack.

What is Hydraulic Oil?

Hydraulic oil is also one of the hydraulic fluids, but both ‘hydraulic oil’ and ‘hydraulic fluid’ terms are reciprocated in some cases. However, hydraulic fluids also consist of other fluids, plain water, salty solutions, and water-oil emulsions.

Hydraulic oil contains oil and additives that transmit power while performing as a coolant and lubricant.

This oil is used in industries like agriculture, construction, mining in heavy machinery, industrial equipment, and automotive systems for key functions such as power generation, heat transfer, lubrication, sealing, and more. It is insoluble in water and in some instances, it’s mineral or synthetic based.  

How to Choose the Right Oil for a Jack?

When you are in the market for jack oils, you need to look at certain important factors. Some of them are viscosity, compressibility, thermal stability, material compatibility, filterability, non-corrosive nature, fire, and heat resistance.


The efficiency of an ideal fluid is mainly depending on the viscosity of the fluid. A medium range of viscosity fluids is preferred for better performance.

Generally, the range between 22 cSt to 32 cSt at 40 degrees Celsius would be better.

If the viscosity range is low, the oil will be thinner in form, and the lubricating ability will be less. So, it will interrupt the performance and may cause difficulty in lifting using the hydraulic jack.

The higher the range of the viscosity, will thicker the form of the hydraulic oil. The better it gets will result in the smooth operation of the jack.

The temperature and viscosity are inversely related to each other, and the velocity of the particles is directly related to their temperature. So, the viscosity attribute decreases in the hydraulic oil when the temperature increases, and that results in to increase in the velocity of the oil particles. As the particles move quickly, they interconnect or interact with other particles for a short period which will reduce the thickness of the oil by lowering the viscosity. It will happen vice versa when the temperature drops.


Desirable hydraulic oil has a higher (but not too high) viscosity to flow smoothly in the system. In hydraulic oil, the percentage of water content should not exceed the range of 0.10 – 0.12%. Even 0.10% is also a critical percentage.

The water-glycol mixture in these oils is fire resistant, provides freeze point protection and some additives provide anti-foam and anti-corrosion abilities. But in some instances, some range of compressibility will affect the hydraulic system.

Minimum compressibility in the fluid will result in the efficient operation of the hydraulic jack. So, in the place where we need higher force, better operation will be done by a lower level of force applied.

Thermal Stability  

The thermal and chemical stability of hydraulic oil will enhance its life. Thermal stability can be achieved when the properties of the hydraulic jack oil do not affect the changing temperature conditions.

The hydraulic oil should be adaptable and suitable to maintain despite extreme cold and hot conditions.

Material Compatibility & Filterability

Compatibility of hydraulic fluid is the attribute of hydraulic oil to mix/blend without deterioration and degradation of properties or performances of the oil.

If the materials are incompatible, it will reduce the filterability of the oil. So it will impact a higher quality lubricant and lead to loss of properties, and may result in an unfavorable impact.

Therefore, it can worsen the performance of the oil than before. Contaminated hydraulic oil may create problems in hoisting due to filter blockage.

On that account, the fluid needs to be clean and filterable for better performance and operation. 

Non-corrosive Nature

In most cases, the hydraulic jacks present in the hydraulic systems are metallic in nature. Therefore, the oil should possess the ability of anti-corrosion and anti-oxidation.

If the metal surfaces of the hydraulic jack are not properly protected, the hydraulic fluid in it is exposed to air and water particles and reacts with chemicals of the fluid causing corrosion.

Fire, Heat, and Foam Resistance

For the quality performance of the hydraulic jack, the fluid must be resistant to fire and heat.

When the lubricants are inflammable, it becomes a considerable risk for the operation. In this case, hydraulic fluids, which are resistant to heat and fire, are strongly considered.

When the system has leakage or sealing failure, too high or low filling level of oil in the tank, cavitation, and poor designing of the system may lead to foaming in the hydraulic oil. Those errors should be rectified for the finer performance of the hydraulic jack.

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Video Credits – hatalarious

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