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Oil is the lifeblood of your air compressor. With the right oil, your compressor can run smoothly and efficiently, ultimately allowing it to reach peak performance. But, with the wrong oil, your compressor may fall victim to excess friction, wear-and-tear, residue build-up, and even damage; which can result in a substantially shortened service life.

So, in this article, we’ll be discussing:

  • Why compressor oil is so important,
  • Different types of compressor oil
  • Which type of compressor oil you should use
  • Oil maintenance and other considerations

To start:

What Is Compressor Oil and Why Is It So Important?

Since cars require oil, most people are familiar with the concept of using oil as a lubricant for machinery. However, the type of oil used in air compressors is not the same as the motor oil you’d put in a car. Rather, compressor oil is specifically designed for air compressors; and it plays an absolutely critical role in the operation, performance, and overall health of your compressor.

Compressor oil serves multiple purposes within the machine.

  • First, it acts as a lubricant to reduce friction and allow moving parts to slide over each other (rather than grind to a halt).
  • Second, it functions as a sealant to ensure gaskets are air-tight, thus facilitating maximal efficiency.
  • And, finally, it acts as a coolant to transfer heat away from the compressor’s central components, thus preventing overheating and malfunction.

One of the main differences between compressor oil and motor oil is the use of detergents. Motor oil frequently includes chemical detergents that help prevent residue buildup within the engine. Compressor oil, on the other hand, does not include these additives, as detergents can damage the machine and contaminate the airflow. Instead, compressor oil has its own unique chemical blend that’s tailored to the needs and conditions of an air compressor.

And with that in mind, let’s now explore the primary air compressor oil types.

Air Compressor Oil Types: Synthetic vs. Traditional

The two most fundamental categories of compressor oil are synthetic and traditional (also known as standard oil or mineral oil). Understanding the distinction between these two categories will help clarify which oil type is best for your application.

Traditional Oil

Traditional oil is made from a mineral base. While it’s generally cheaper than synthetic oil, it’s also more volatile and reactive, which leads to some notable disadvantages including:

  • shorter service life
  • lower efficiency
  • increased sludge
  • and chemical irregularities

Consequently, traditional oil is typically more suitable for small-scale or light-use applications.

Synthetic Oil

Synthetic oil is made from a synthetic base. It’s generally more expensive than traditional oil, but that comes with significant benefits including:

  • longer service life,
  • fewer oil changes
  • reduced sludge
  • increased temperature resistance
  • greater reliability
  • and increased performance.

Consequently, synthetic oil is typically preferable for large-scale or heavy-use industrial applications.

There are a number of different subsets within the synthetic category. Here are some common types of synthetic oil:

  • Polyalphaolefin (PAO) – the most common type of synthetic oil, made from petroleum. Advantages include low volatility and thermal stability.
  • Polyglycol (PAG) – a non-petroleum synthetic oil that’s resistant to oxidation. Advantages include increased efficiency and minimal deposit buildup.
  • Polyol Esters (POE) – another non-petroleum synthetic oil. Specifically engineered for refrigeration applications.
  • Blended Oils – by mixing mineral oils and POA, a balance can be struck between the chemical advantages of synthetic oil and the lower cost of traditional oil.

Now, after reviewing these options, the natural question that follows is…

Which Type of Compressor Oil Should You Use?

Oil is certainly not a one-size-fits-all solution, and selecting the right compressor oil is key. As we discussed above, you can’t just put regular motor oil in an air compressor: there are special types of compressor oil that are designed to optimize performance, efficiency, safety, and longevity. And on that note, the best compressor oil for your specific application depends largely on the manufacturer’s recommendations.

Manufacturers perform extensive research and testing to determine the ideal oil type for their machines. So, if you’re wondering which type of oil is best for your compressor, the first thing you should do is check your Owner’s Manual and warranty — there should be a set of guidelines for which oil to use.

Following the manufacturer’s guidelines will not only ensure that you’re using the ideal air compressor oil type, it will also abide by the warranty requirements; whereas using the wrong type of oil could nullify the warranty.

If you can’t find the manufacturer’s specifications, here are some general guidelines to follow:

  • Synthetic oil – usually better for industrial applications.
  • Non-Detergent – if it’s compressor oil, it should automatically be ND.
  • Viscosity Grade of 20 or 30 SAE – 30 in normal environments, 20 in cold temperatures.

That being said, if you’re uncertain, it’s advisable to consult an authorized distributor or service technician who’ll be able to assist you in determining the best type of compressor oil for your particular situation. If you need help, you can contact TMI for answers to any of your air compressor questions.

Compressor Oil Maintenance and Other Considerations

In addition to using the right type of oil, you also need to be cognizant of oil quality. There’s a large market for cheap oil, which may seem tempting — but low-quality oil can negatively impact the function and health of your compressor. This can ultimately shorten the lifespan of your compressor and require you to replace the engine, which is very expensive. So remember, investing in premium-grade oil will pay off in the long run.

Proper oil maintenance is also key. Even the highest-quality oil will need to be changed on an annual basis, if not more frequently depending on the circumstances. You should also be monitoring the oil and testing it to make sure there’s no water build-up. Doing so will help protect your compressor from malfunction and promote optimal performance.

If you have any questions about air compressor oil, contact our team of experts at TMI. We carry premium Sullube oil products and our team will help you select the ideal oil type, along with any other parts you may need for your compressor. We’re also happy to provide any other insights to ensure your compressor is running as efficiently and effectively as possible.