Choosing the Right Oil for Your Air Compressor

Unless you have an oil-free air compressor, it’s important to keep up with oil changes. Oil lubricates your compressor so it will run smoothly, quietly, and without corrosion. So, how do you choose air compressor oil?

Standard air compressor oil is great if you don’t use your compressor too often, but synthetic is the best for frequent use. Synthetic air compressor oil lasts longer than standard oil because it’s refined, so you won’t have to change it as often. It is also less likely to turn into sludge when it gets cold compared to standard air compressor oil.

You can use hydraulic oil as an alternative but never put motor oil in an air compressor. Follow along as we take a deep dive into air compressor oil and see which type is the best option for your compressor.

What Does Air Compressor Oil Do?

Just like cars, air compressors require oil to run. While you can find oil-free air compressors, many people prefer oil-injected air compressors. The oil in an air compressor prevents friction that would otherwise cause metal to rub against metal.

Not only would the air compressor run loudly, but it would also suffer damage from the friction without oil. The oil also helps maintain a strong seal between the gaskets, and that’s important for your air compressor to run effectively. Air can leak from your compressor if the gaskets aren’t sealed, and it will greatly reduce the performance.

Oil also helps maintain a good temperature within an air compressor so heat doesn’t build up and damage the components. Air compressor oil typically has more purity than motor oil because of the lack of detergent. Unless you have an oil-free compressor, you must choose the right oil for your air compressor.

How Do I Know What Type of Compressor Oil to Use?

The best type of air compressor oil for you depends on your needs and the unit you use. There are two types of air compressor oil to choose from: standard and hydraulic. Let’s look at the difference between them.

Standard

Standard compressor oil is quite natural in that it has a high mineral content. You won’t find standard compressor oil at most businesses and auto body shops. That’s because you must replace it sooner than synthetic oil which is a hassle when you run a busy business.

It isn’t refined, and because of that, you will find more impurities in standard compressor oil. The impurities can turn standard compressor oil into a sludgy consistency. This can slow down your output, and even damage your air compressor.

Air compressors burn through standard oil much faster than synthetic oil, unfortunately. That makes many people lean toward synthetic oil, but standard oil is a great option for light use. Standard oil is also quite temperature-sensitive, so it will quickly thicken when it gets cold, and you must replace it.

Synthetic

While standard oil is more natural, synthetic compressor oil I more practical for many people. Synthetic oil is also the best option if you frequently use your air compressor. It is refined and less prone to sludge than standard oil which makes maintenance much easier.

You should still check the oil level daily with synthetic oil, but you’ll be less likely to find sludge and dirty contaminants. Synthetic oil is also less sensitive to temperature, and that’s quite helpful if you live in a cold climate. Standard oil is likely to thicken and weaken as the temperature drops or if your compressor is in a cold workshop.

Synthetic oil can still thicken, but it’s less of a problem and it’s much easier to work around. You can use your air compressor for much longer without changing the oil if you use synthetic oil. The consistency and refined nature of synthetic oil make your compressor less likely to use up so much quickly, and that’s quite convenient.

Can You Put Motor Oil Into an Air Compressor?

You shouldn’t put motor oil into an air compressor. Motor oil meant for cars features lots of detergents, and that can be bad for any air compressor. The detergent is useful for cars because it can keep the metal clean, but that’s not necessary for an air compressor.

Your air compressor can become full of impurities if you put motor oil into it. It can quickly turn into sludge and the motor oil can’t protect the metal parts of your compressor from rubbing into each other. Carbon will also build up within your air compressor if you use motor oil.

Not only can that damage your air compressor, but it can also make your workspace unsafe. Motor oil may even trip your air compressor’s breaker because it will recognize the impurities, sludge, carbon, and difference in pressure.

Can You Put Hydraulic Oil in an Air Compressor?

You can use hydraulic oil as an alternative to air compressor oil, but it’s not ideal. It’s a much safer alternative to air compressor oil than motor oil, but air compressor oil is still the best option. As the name suggests, hydraulic oil is meant to lubricate hydraulic machinery.

It doesn’t oxidize and rust machinery, so you don’t have to worry about corrosion in your air compressor. Hydraulic oil also doesn’t become sludgy from temperature fluctuations, especially during cold weather. That alone makes it somewhat better than standard air compressor oil in some cases.

Granted, you should only put hydraulic oil in an air compressor if it’s an emergency and you don’t have any air compressor oil on hand.

How Often Should You Change Standard Compressor Oil?

You should change standard compressor oil after every 100 to 200 hours of use. However, several factors affect how often you should change it. Because standard oil is prone to impurities, it can thicken and turn into sludge much sooner than 200 hours of operation in some cases.

You can avoid this if you stick to reputable compressor oil brands, but it can still thicken from the temperature alone. For example, you must replace standard compressor oil much sooner if the compressor is in a cold and poorly ventilated room. It will quickly thicken if the temperature drops too low, and it will become useless.

Check the oil level and filter condition each time you use your air compressor. That is especially important with standard oil because of the impurities. Some people can get by with changing the oil once per year, but you may need to change it every few months if you use your compressor often. In that case, it may be better to switch to synthetic oil.

How Often Should You Change Synthetic Compressor Oil?

Change the synthetic oil in your air compressor once every 3 months or as needed. Synthetic oil lasts longer than standard oil, but people who use synthetic oil often use their compressors more often. Because of that, you may go through it faster than you’d go through standard oil simply because you use it more.

Use a dipstick to check the oil level in your air compressor daily or at least a few times per week. It doesn’t take long to reach 1,000 hours of service when you run an air compressor in a professional setting. Some big businesses must change the synthetic oil in a compressor monthly, but that’s rare and often unnecessary.

Some air compressors can go up to 1,000 hours without an oil change when running synthetic oil. While that is quite convenient, you can’t guarantee that your oil will last that long. Temperature fluctuations and impurities in the air can ruin synthetic oil, even if it’s less sensitive than standard oil. Change the oil right away if it becomes too thick and sludgy, or else it won’t properly lubricate your compressor.

Are Oil-Free Air Compressors Better?

Oil-free air compressors are rarely better than oil-injected compressors. Sure, oil-free compressors are often lighter, more portable, and easier to use. That said, they are also inconsistent and don’t last nearly as long as oil-injected air compressors.

Oil-free compressors have nothing to protect themselves from the friction of metal rubbing against metal. This makes the metal parts wear out faster than they normally would. They also run loudly which can be quite annoying when you work in a small space.

Stick with oil-injected air compressors if require a high output and want a compressor that will stand the test of time. Otherwise, you can’t go wrong with a small oil-free air compressor if you need a simple compressor for small jobs and hobbies.

So, What is the Best Type of Air Compressor Oil?

Synthetic is the best type of air compressor oil. It lasts much longer than standard air compressor oil because of the lack of impurities. This keeps the oil consistency perfect and you are less likely to encounter sludge that will slow down your working speed.

Standard oil is more prone to consistency changes when it gets cold, and that can be a problem throughout winter. You must change the oil every 100 to 200 hours with standard air compressor oil, but you can wait up to 1,000 hours with synthetic oil. Check the oil level daily whether you use standard or synthetic air compressor oil.