When it comes to air compressor oil, the common debate tends to be whether synthetic oil or mineral oil is the better choice. Air compressor oil lubrication can be made using either synthetic or mineral oil bases.  

Mineral oil-based tends to be the standard oil for air compressors. Synthetic oil undergoes a significant amount of processing.

Both offer advantages against the other in different situations. Mineral oil boasts the best attributes for light duty intermittent use, whilst synthetic oil boasts the best attributes for heavy duty continuous use.

However, we’re certainly not limited to these air compressor oil types. There are a few different types of air compressor oil substitute readily available and suitable for use.

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What Oil can I use in my Air Compressor?

Those types of air compressor oil substitute that are available include:

  • Automatic Transmission Fluid (ATF)
  • Hydraulic Oil
  • Non-detergent Synthetic Motor Oil

Automatic Transmission Fluid (ATF)

ATF is a well known substitute for air compressor oil in the successful performance of a variety of tasks. They are widely used in automotive applications like car transmissions because it does very well at:

  • Cooling varying components
  • Keeping the components free of deposits
  • Serving as a hydraulic medium
  • Resisting breakdown under the stress of operation
  • Minimizing the friction and thus wear and tear

Air compressors also require cooling of components and try to avoid friction wear and tear so, seeing as these tasks ATF can complete effectively are very similar to those required in air compressors, ATF is very commonly used as air compressor substitute oil.

Robust base oil and superior additive packages are the main sources of most automatic transmission fluids. These contain anti-wear agents, detergents, demulsifiers and antioxidants allow for long service intervals.

Advantages of Automatic Transmission Fluid (ATF)

Some real advantages of using ATFs as your air compressor oil compared to another substitute for air compressor oil are:

  • ATFs help air compressors resist breakdown during the heating that is produced when they operate.
  • ATFs contain detergency helps minimize the deposits created by broken oil during heating and therefore they help to clean the air compressor.
  • The base oil and antioxidants help in avoiding degradation during compression, when the air is driven through the oil which may cause oxidation and premature failure of oil.

Disadvantages of Automatic Transmission Fluid (ATF)

Of course, there must be some disadvantages to consider, these are:

  • There is a very good chance the ATF will not be compatible with your air compressor, so you must ensure that it is before putting it in your system.
  • The detergents they contain can be very bad for air compressors and may cause damage.
  • For a valid warranty, it is required that you use the compressor manufacturers advised oil otherwise you risk a warranty void.

Hydraulic Oil

Hydraulic oil boasts a number of good characteristics that make it an ideal substitute for air compressor oils. First of all, at low temperatures hydraulic oils has low viscosity which allows it to flow freely given their resulting low density.

Hydraulic oils are typically suited for work in small garages, and may not perform as well as air compressor oil when it comes to bigger industrial sized piston air compressors.

They show good performance with sealant materials that are used to manufacture an air compressor, making them a good substitute for air compressor oil.

Advantages of Hydraulic Oil

Some advantages of using hydraulic oil as substitute oil for an air compressor include:

  • Corrosion-resistant/immune to oxidation thus are able to protect the air compressor from rust and wear.
  • As mentioned, hydraulic oil has low viscosity allowing it to flow potentially better than other alternatives.
  • Not affected by low temperatures so are ideal in areas of average low temperatures.

Disadvantages of Hydraulic Oil

On the other hand, some disadvantages of using hydraulic oil are:

  • Hydraulic fluids lack good water separability in comparison to compressor oil.
  • Not fundamentally as, if at all, capable of being used in bigger industrial sized air compressors.
  • For a valid warranty, it is required that you use the compressor manufacturers advised oil otherwise you risk a warranty void.

Non-detergent Synthetic Motor Oil

Non-detergent synthetic motor oil can also be used as a substitute as well, however I will add that this should be your last option.

The artificial chemical compounds in synthetic oils make them far more refined than other oil types. Due to the multiple manufacturing processes they go through, they’re best for specific purposes only.

Advantages of Non-detergent Synthetic Motor Oil

Some advantages of using these non-detergent synthetic oils as air compressor oil include:

  • Allows the air compressor to accomplish tasks at high and low temperatures.
  • Protects the air compressor from overheating.
  • Can help reduce the operational noises.

Disadvantages of Non-detergent Synthetic Motor Oil

On the other hand, some disadvantages to consider:

  • They’re made for specific purposes only… choosing the wrong synthetic oils can cause serious damage.
  • For a valid warranty, it is required that you use the compressor manufacturers advised oil otherwise you risk a warranty void.

FAQs (Frequently Asked Questions)

Can you put motor oil in an air compressor?

Yes, it is possible. Use a standard weight motor oil in your air compressor.

This isn’t however advisable. Neither should you mix synthetic oils with mineral oils, but it can definitely get you by. It may not be recommended to run a multi-viscosity oil in a compressor as it can cause some foaming issues which are other wise avoidable.

If you are to use a motor oil, stick with a 20W or 30W oil as these are your best choice. A 10W oil can be considered in cold weather to make it easier to start.

In desperation, motor oil may be a short term substitute, but it’s likely to have a long term impact on the efficiency and life of your compressor.

Can I use 10W30 in my air compressor?

Yes, some compressors do allow the use of non-detergent 10W30 synthetic oil in the case of an emergency.

10w30 oil has a viscosity of SAE10 at lower temperatures (w standing for “winter”) and SAE30 at normal / higher temperatures.

It’s not advised to use an oil with a variable viscosity profile like this in your air compressor typically.

That being said, consult your air compressor user manual as each air compressor manufacturer might have their own specific advice around these types of oils.

Can I use 5W30 in my air compressor?

5w30 oil has a viscosity of SAE5 oil at lower temperatures (w standing for “winter”) and SAE30 at normal / higher temperatures.

It’s not advised to use an oil with a variable viscosity profile like this in your air compressor typically.

Again, with that being said, consult your air compressor user manual as each air compressor manufacturer might have their own specific advice around these types of oils.

Do you have any questions in regard to air compressor oil substitutes? Please leave a comment below and a photo if applicable so that someone may help you!