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Air Compressor Oil Types USER GUIDE

Published Categorized as Air Compressor Oil Guides 2 Comments on Air Compressor Oil Types USER GUIDE

There are an overwhelming number of grades of lubricating oil available on the market today, not to mention versions that have been engineered to various levels from refined mineral oils to fully synthetic lab-designed oils.

In addition, many oils on the market simply proclaim to be ‘Air Compressor Oil’ which can leave you wondering whether it’s really the right kind of oil for your type and brand of air compressor.

In this handy user guide, I’m going to aim to up-level your oil knowledge, so this seemingly complicated subject of choosing the right air compressor oil is drastically simplified – whilst giving you an understanding of some of the fundamentals of air compressor oil so you also understand your choice.

It must be noted, that air compressors are also available oilless… (or oil-free) this does not imply that they don’t require lubrication, but instead, they are pre-lubricated and do not need user maintenance to change the oil. Visit our Oilless Air Compressors vs. Oil Compressors guide for more information!

Table of Contents

What Kind of Oil is Used For an Air Compressor?

Both mineral oil and synthetic oil are commonly used oil types for air compressors that can be seen advertised as ‘Air Compressor Oil’ stocked on the shelves of your local hardware store.

For a home workshop compressor user, a mineral-based air compressor oil is perfectly suitable and cost-efficient – it’s the standard compressor oil of choice.

For industrial air compressors, the choice and sophistication can be as broad as the applications in which compressors can be used.

This is because industrial air compressors tend to use blended oils to suit a range of criteria, including:

  • Air compressor pump type
  • Peak ambient operating temperature
  • Lowest ambient operating temperature
  • Average ambient operating temperature
  • Inducted air quality
  • Required output air quality/contamination level

Inevitably with consistent air compressor usage, plant dependency, and commercial implications, industrial air compressor users need to concern themselves with the long-term implications of choosing a particular kind of oil.

Oxidation of the air compressor oil can be a serious concern, resulting in the formation of thickened portions of the oil or “sludge”, and also a phenomenon referred to as “varnishing”. Varnishing ultimately leads to the denatured oil sticking to the internal surfaces of the air compressor pump. This might sound favorable, but this sticky, oxidized oil does the opposite of lubricating the parts it sticks to – instead attracting debris and creating an extremely abrasive surface over time – drastically reducing the life span of your air compressor pump.

Other, alcohol-derived oils (Polyol Esters / POEs) have a property that can keep lubricated parts clean – acting as dispersants.

It’s easy to understand, therefore, why industrial air compressor oils can also be made up of blends of various synthetic, and mineral oils.

In cases where compressed air can come into contact with food, particularly the case in pneumatic systems controlling food processing or packaging, the oils used would first and foremost be selected based on their non-toxic properties. Engineering the toxicity out of the oil necessitates that they’re synthetic oils.

If in doubt, consult your air compressor user’s manual where you’ll find the manufacturer’s recommended oil type – or even specific oil brand and code to purchase.

This guide, explaining oil terminology along with your user manual should stand you in good stead.

Air Compressor Oil Types USER GUIDE

What Is Air Compressor Oil?

Air compressor oil is a lubricant that reduces friction between the moving parts of the air compressor pump, reducing wear and tear and assisting in cooling.

Air compressor oil is typically SAE 20 or SAE 30 in oil grade or viscosity when talking in conventional oil grade terminology.

Air compressor oil has specific additives to make it perfect for the duty cycle it endures inside your air compressor pump. In contrast to conventional motor oil, which is more commonplace, air compressor oil doesn’t contain a detergent and typically has lower levels of sulfur (sulfur) and carbon. You can get non-detergent motor oil, however.

Carbon and sulfur content are ultimately measured as a percentage by weight – but can also sometimes be referred to as a ratio on the bottle. Air compressor oils can also sometimes be labeled as “low sulfur” or “low sulfur” depending on which part of the world you’re in.

Why do air compressors even need oil?

Air compressors require oil lubrication systems as they have high-speed moving parts operating inside the air compressor pump, as is the case in a conventional combustion engine. Without oil, these components would quickly heat up and wear out resulting in complete failure of the air compressor pump.

An air compressor pump needs oil like a gasoline engine needs motor oil – to operate efficiently over time without the need to replace parts that have worn out prematurely.

Air compressors therefore need oil to operate as designed, without overheating, efficiently, for the intended life span of the air compressor pump.

Does the air compressor pump type on the oil bottle matter?

There are different types of air compressor pumps with different oil quantity and property requirements. The internal components of these compressor pumps move and operate in a variety of different ways. By far the most common compressor pump configuration on a workshop air compressor is a reciprocating compressor pump. Much like a reciprocating engine, there’s a piston, connecting rod, and crank shaft.

Many compressor oil bottles may therefore specify “reciprocating/vane” on them to add a further layer of complexity to the choice of oil type. In reality, the oil manufacturers are trying to be helpful and signpost that their oils can perform inside specific compressor pump types and configurations.

If the compressor pump configuration isn’t mentioned on the oil bottle, assume it’s all-purpose air compressor oil which will work in reciprocating, vane, rotary screw, and centrifugal air compressors.

If the compressor pump configuration IS mentioned on the oil bottle, it’s highly likely it will include ‘reciprocating’ which there’s a fair chance your air compressor pump is. If in doubt, consult your user manual – or ask a question here on about-air-compressors.com!

Can You Put Motor Oil in an Air Compressor?

You cannot use motor oil to lubricate an air compressor pump without permanently reducing the life span and efficiency of the compressor. Motor oils are designed to operate in lower temperatures and greater volumes than air compressor oils.

An oil for air compressor is specially formulated for use within air compressor pumps. Unlike motor oil or engine oil, air compressor oil doesn’t contain many additives used to clean, restore, and preserve the inside of an engine.

Compressor oils on the other hand, when produced go through several processes, such as; solvent extracting, desalting, and evaporation – all designed to make them robust and effective at high temperatures.

How to Choose an Air Compressor Oil?

The logic behind your choice of what air compressor oil to use should be as follows:

Situation: If your air compressor is under warranty…

Choice: You should use the oil that is recommended by the manufacturer and usually noted in the compressor manual/guidebook.

Situation: If the warranty period for the air compressor has ended…

Choice: then you could buy suitable compressor lubricating oil from a hardware store to use in your compressor.

Note, that this rule should only apply to home DIY compressors. Some of the more sophisticated and larger compressors such as rotary screw compressors, reciprocating compressors, rotary vane compressors, or centrifugal compressors – that are used by industry, have very specific requirements for oil.

What happens if I use the wrong type of air compressor oil?

Using the wrong oil for your air compressor could lead to excessive wear, permanent damage and reduction of efficiency, permanent reduction in flow rate, and even complete failure of the compressor pump. Oils derived from alcohol bases (POEs) can even react with plastics and rubbers which could lead to the failure of gaskets, o-rings, and other air seals – leading to persistent leaks, an inability of your air compressor to build, hold, or reach cut off pressure.

But don’t panic just yet! (if you’re the home workshop user)

If you’ve purchased an oil advertised as an ‘Air Compressor Oil’ it’s highly likely the only real variations in oil type you have on your hands are:

  • Mineral or synthetic (or semi-synthetic) (which will ultimately all be appropriate choices)
  • SAE 20 or SAE 30 (which have a small difference in viscosity)
  • Low Sulfur or Sulphur (which all Air Compressor oils air in contrast with a standard motor oil)

Whichever of the list above you have in your hands, none of these oils should pose a critical risk to your air compressor pump.

That being said…

It’s advised to use the oil recommended by the manufacturer of your air compressor or you could void the warranty.

What Type Of Oil To Use In Your Air Compressor – Video Guide

Which is Better, Synthetic or Mineral Oil?

When it comes to synthetic vs standard air compressor oil (mineral oil), the choice is very much driven by your duty cycle – how frequently and continuously you use your air compressor.

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 oils undergo a significant amount of processing.

When making a decision on which one to use, it can take some careful consideration. Both mineral and synthetic oils are both very suitable for oil-lubricated air compressors so the type of work you intend to do with your air compressor and the amount of use must be analyzed.

It can be recommended that if you do not continuously use your air compressor then a standard mineral oil air compressor lubricant can be best suited to you. This is because they’re perfect for light to medium-duty air compressor operations. Most importantly, these oils are cheaper than synthetic blends.

If you’re continuously using your air compressor in an industrial setting, synthetic blends can be the better choice due to their more regular use. It is said by multiple users that their oil-lubricated air compressors run a lot smoother and quieter on synthetic oil lubrication. Not only this, but synthetic oils have an overall greater temperature range and stronger protection against the air compressor overheating.

Synthetic Oils vs Standard Compressor Oils

Duty CycleMineral OilsSynthetic Oils
Light Duty / Infrequent UseBestOk
Heavy Duty / Continuous UseOkBest

Alternative Oils For Air Compressors (Using a Substitute Oil)

Potential alternative compressor oils include:

  • ATF – Transmission Fluid
  • Engine / Motor Oil
  • Hydraulic Oil / Hydraulic Fluid

For more information on air compressor oils substitutes, visit our guide!

Does Every Air Compressor Need Oil?

All air compressors are mechanical machines that need oil at some point.

“What about oil-less air compressors?” I hear you say…

Oilless air compressors aren’t actually completely oil-free or devoid of oil. Essentially the term oilless refers to the fact that the compressor doesn’t need to have its oil changed or topped up. In fact, oilless air compressors come “factory sealed” so that the original lubrication cannot be replenished.

Over time, oilless air compressors lose their lubrication through degradation of their oil coatings and will eventually run out of lubrication, running under high wear – and eventually seizing up.

This is typical of DIY or home-use air compressors that have a light-duty cycle or a highly infrequent duty cycle – such as a car tire compressor that gets pulled out maybe once every 3 months over the course of its life.

So if you have an air compressor at home and you’re wondering whether you should be topping it up with oil, check the user manual! It may well be a factory-sealed unit that doesn’t require you to change or top up the oil.

Most reasonably duty cycle compressors (including many DIY home-use air compressors) do require you as a compressor owner to monitor oil levels and top up the oil based on a usage cycle.

List Of Best Air Compressor Oils

Numerous oils compete at the top for some of the best on the market, here we will look at a few of those best. To give you a better idea of what you’re looking for. It is, however, recommended to follow your air compressor manufacturer’s guidelines.

Mineral Air Compressor Oil

Mobil 101016 Rarus 427 Compressor Oil, 1 Gallon is a mineral base oil and one of the best available. It is suitable for reciprocating and rotary-type machines which have a lower viscosity air compressor oil grade. This oil can significantly help to reduce the noise of the air compressor and the running temperature during operation.

This oil is formulated with high-quality mineral oils and a very high-performance additive system, that is designed to provide the best of the best equipment protection. This also provides reliability for compressors that are operating under anything from mild to severe conditions. They provide excellent wear protection and have the ability to reduce maintenance costs by minimizing any potential problems with equipment.

They have very high FZG ratings which make them an excellent air compressor lubricant for any compressor system that uses gears and bearings. This makes them an excellent selection for crankcases.

Synthetic Air Compressor Oil

Powermate PX PO18-0084SP 100% full synthetic compressor oil is one of the best available. It starts 10 degrees colder than other synthetic blend compressor oils and performs 50% better at O degrees Fahrenheit than standard mineral air compressor oil. It offers a high viscosity index providing it with better performance in a wide pump operating temperature range. This oil also works well in warmer temperatures.

One thing to note is that if your compressor is more than eight years old and the building pressure within it struggles, then it is certainly suggested against using this particular oil instead of looking for an alternative.

The oil can make old oil-lubricated air compressors effective again, help eliminate the start-up sound of the system, and not get affected by cold weather on startup. On the contrary, the oil forms sludge and has a strong smell that can last for a long time.

Campbell Hausfeld MP12 Air Compressor Oil

Campbell Hausfeld is one of the most reputable pneumatic brands active in today’s market, you really can’t go wrong with their oil. This oil can add to the pump life of the air compressor by reducing the carbon build-up on the valves thanks to its singular viscosity.

Unlike most oils, this compressor oil does not provide an unpleasant smell. It again can prevent noise from the air compressor and stop overheating of the system when it operates for a long time. The oil enhances the durability of the part by preventing corrosion, which tends to be the most common reason for parts wearing out and requiring maintenance or replacement.

A few negatives, but potentially not seen as that negative at all, are that the oil pours really quickly and due to its transparency, close attention must be paid when filing your air compressor.

AMSOIL Synthetic Compressor Oil

Air Compressor Oil Properties & Characteristics

There is a whole range of properties of compressor oil that we could go into, but I’ll cover the 3 that are of main concern when selecting a compressor oil:

  • Operating temperature range
  • Additives
  • Viscosity

Operating Temperature Range

Oils, of any kind, not just compressor oils suffer from oxidation and denaturing due to heat. As heat increases, so does the rate of oxidation and the oil loses its intended lubricating and protecting properties.

Extreme temperatures such as below freezing or above 100-120 Degrees Fahrenheit will often require specialist oils. Equally, your compressor manufacturer will have advised the normal operating temperature of the surroundings for your compressor in the user manual.

Obviously, your compressor also generates heat, so the temperature range for the operation of the air compressor stated by the manufacturer won’t also be applicable to the oil itself – which will have to endure much hotter temperatures inside your compressor than the ambient surroundings.

It’s best to consult your user manual – however, you may not find a specific compressor oil temperature range stated. In the event, you’re left scratching your head, wondering whether the compressor oil you have will do the job – don’t panic.

The majority of Air Compressor Oils are designed to work well within typical operating temperature ranges for oiled air compressors. If in doubt, consult your local workshop equipment dealer for reassurance on a specific oil.

Additives

Oil additives are sacrificial chemical elements that impart properties onto the oil that the underlying oil simply can’t deliver.

For example, motor oils tend to have a detergent content which helps to prevent a build-up of carbon deposits – and prevent the carburized oil from being deposited in the first place!

Air Compressor Oils tend to have more concentration of additives that act as preservatives to prevent corrosion and rusting inside the compressor. Additional lubrication, or “anti-wear additives” can be present in a range of air compressor oils, even some mid-range compressor oil.

Anti-oxidation additives are some of the most important, especially with compressor oil seeing reasonably high temperatures under continuous use. This anti-oxidation additive helps to slow the rate of oxidation and denaturing of the oil.

All of these additives are sacrificial. So over time, these additives lose their potency within the oil, and essentially the oil returns to its “pre-additive” state, but also with a bunch of oxidation thrown in! This is why it’s REALLY important to change oils, even when oil levels “look ok”.

It’s also another reason why completely CHANGING the oil is important, rather than just continuously topping up the compressor oil – leaving the aged, degraded oil to mix with the fresh – additive-rich compressor oil.

Viscosity

The air compressor viscosity is often referred to as the air compressor oil grade or air compressor oil type. With the advent of modern oils, viscosity levels have tended both towards the nominal SAE 20 -30 range, meanwhile, the more extreme viscosity level oils are still available, but they’re less commonly used in machinery in general.

It’s no different with air compressor oil. A SAE20 or SAE30 oil is perfectly suited for use in an air compressor.

There isn’t actually a huge difference between SAE20 or SAE30 for air compressors – certainly not one that would mean you MUST use one or the other.

Fundamentally, SAE20 is slightly less viscous, meaning at colder temperatures the oil will cause less drag on the compressor and it’ll run slightly more efficiently.

With SAE30 air compressor oil, the viscosity (thickness) is a little higher (more viscous) so at colder temperatures, the viscosity might be a little higher than desired – meaning the compressor would run slightly less efficiently using SAE30 at colder ambient temperatures.

It’s worth bearing in mind that as the compressor runs, the heat generated in operation will reduce the viscosity of both SAE20 and SAE30 compressor oils. Under sustained use in a lower-temperature environment, SAE 20 oil will outperform SAE 30 in terms of efficiency.

Under sustained use, in a higher or moderate temperature environment, the air compressor oil number SAE 30 will retain more of its lubricating properties than SAE 20 compressor oil. Meaning the SAE 20 compressor oil will have sub-optimal viscosity (it will go thinner) at a lower operating temperature than SAE 30 compressor oil.

This is an important distinction, but probably the only one that will make a significant (noticeable) difference to compressor users who are operating their compressor daily or continuously.

Where Can I Buy the Best Air Compressor Oil?

You can find and buy air compressor oil at almost any of the very well-known online stores like Amazon. If you don’t quite fancy ordering online and prefer to have air compressor oil near me, your local auto parts shop is a great place to look. It is advised to ensure your oil is available at your chosen store to save you time.

How Often Should You Change Air Compressor Oil?

  • Change the oil every 3 months on a reciprocating air compressor
  • Change the oil between every 1000 to 2000 service/operating hours on a rotary screw compressor

The answer to this question is unfortunately not as straightforward as you may wish. The answer will vary depending on the size of the air compressor in use or even the type. The time after which the oil needs to be changed will vary significantly from air compressor to air compressor. The best place to gain an understanding of this regularity will be inside your air compressor manual provided by the manufacturer.

If you’re wondering how to change your compressor oil then please visit our guide. Some of the questions you will want to have answers to before you open the compressor oil sump are covered on this page. A basic few steps to follow for changing the oil in your compressor are as follows.

How to Change Air Compressor Oil

  1. Switch off your air compressor and unplug it
  2. Let the air compressor cool down
  3. Drain the air compressor of any oil that remains inside
  4. Refill with the required amount of compressor oil

How to Check Oil Level on an Air Compressor?

Much like a car engine, some air compressors provide a dip-stick that has an oil level marker/indications on the stick to help you check whether the compressor oil is running low.

However, it’s quite common to find a clear portion or “sight glass” on the side of the oil reservoir or motor mechanism. Some compressors even have a completely clear reservoir for high visibility from a distance.

Once again, markings and indicators are typically provided on these sight glasses. At a minimum, some user manuals might simply say that the oil level must be visible in the small sight glass “porthole”.

It’s important to remember that oil expands under heat! So if the user manual indicates that the oil levels should be measured when the compressor is cold / before the operation – make sure to follow these guidelines! Your compressor could be showing a perfect oil level when hot, but as the whole system cools you could find the oil level is actually below the desired level.

Compressor Brand Oil Pages

FAQs (Frequently Asked Questions)

What is the Difference between Air Compressor Oil and Motor Oil?

Well, it’s sort of in the name, compressor oil is specifically created for air compressors and motor oil is specifically created for motors. Compressor oil is a non-detergent oil. It’s important to use compressor oil to comply with the guidelines provided by your air compressor manufacturer. Motor oil most commonly contains all sorts of detergents, which as you may know, are very beneficial for the internal combustion engine. It, however, can be very harmful to the air compressor, causing a greater amount of carbon build-up in a shorter time. If you were to use a different oil like motor oil, this may change your warranty void as mentioned, taking away any advantages of the warranty.

What Viscosity Air Compressor Oil Should I Use?

Viscosity refers to the texture and/or consistency of the air compressor oil. Most manufacturers will tend to recommend SAE20 or SAE30. SAE20 is more suited to colder areas, and SAE30 is more suited to warmer temperatures due to its greater viscosity. Viscosity is a very important characteristic to analyze. Damage to your air compressor may occur if the consistency of your oil is either too thick or thin. Not only damage but work will be delayed.

What’s the best oil to use in air compressors?

This completely depends on your duty cycle, but ultimately we’d advise a high-quality synthetic oil will a high density of preservatives and anti-corrosion additives.

How much oil does an air compressor need?

Typically a couple of fluid ounces of compressor oil will do the trick. If you find yourself emptying an entire bottle of compressor oil, you may well have a leak! That being said, the amount of oil that goes into your compressor is highly dependent on the compressor size. Larger compressors typically take more oil as their mechanical pumps are greater in size and ultimately volume.

What oil should I use in my air compressor?

You may use synthetic or mineral oil in your air compressor and have it operate perfectly. You should avoid oils with a detergent additive, these are common in motor oils. So specify a non-detergent oil. In terms of viscosity, you’ll want an SAE 30 or SAE 20 air compressor oil. An ISO 100 oil like this one from AMSOIL is typical.

Do air compressors need oil?

Not all air compressors need oil no! All compressors do however require a method of lubrication to moderate heat, friction, and the wear-down of the pump and critical components. Some compressors are specifically oil-free or oil-less, therefore their lubrication comes from a special material coating rather than using oil.

What type of oil do air compressors use?

Typically air compressors will use synthetic or mineral oils, and should preferably be non-detergent. In terms of the viscosity of the oil, it should be around SAE20 or SAE30. Typically your air compressor manufacturer will inform you of what oil should be used with each compressor model. If you can’t find locate your user’s manual where the information will be, you should contact the manufacturer directly.

How Do I Top Up the Oil in My Air Compressor?

Time needed: 5 minutes

To change the oil in your air compressor follow these steps:

  1. Switch off the air compressor

    Ensure the air compressor is switched off, disconnected from the electrical supply, and cool

  2. Empty the oil

    Undo the drain plug (sump plug) and let the oil drain into an empty container

  3. Refill with fresh oil

    Replace the drain plug and top up with your fresh compressor oil

What Is an Oil Air Compressor?

Like a reciprocating engine, an air compressor uses a moving piston inside a cylinder to draw in air and then compress it. Instead of igniting the air with fuel and spark, the compressed air system sends the air into your air tank, where it’s held at high pressure.

All that moving around the piston inside the cylinder causes a lot of heat and friction. That leads to wear and tear on the item, which isn’t good. Eventually, the piston seals will wear down, and the cylinder will make less air pressure than it was designed to do.

The best way to solve the problem is with lubricating oil. This is precisely like having oil in your car, and for the same reason. It reduces heat and friction. When heat is built up, the oil wicks away from the pump case and the cylinder.

Only by ensuring that the proper amount of oil gets into the cylinder and piston will the pump operate the way it should. The main difference between oilless and oil air compressor units is this oil lubrication and the need to make sure that it is there. It also means that the operator will need to change it occasionally, which means more maintenance.

Related Air Compressor Oil Reading:

Reader Questions & Responses About Compressor Oil

What if you put the wrong oil in the air compressor?

Question

I put 10/30 oil in my air compressor, started it up run a little bit then stopped.

The next day I found out I put the wrong oil and overfilled it, drained the oil out, turned on it started up, and turned it off right away.

Response

Robert, I guess it might depend on what make and model of the air compressor.

The typical automotive oil has additives and detergents in it that aren’t necessary, and probably will, in the long term, damage some compressor pump components. In the short term, the viscosity is that of a normal compressor lubricating oil, so not too much damage can have been done, but again, it depends on the make and model of the compressor.

Let us know how it turns out as a comment here, will you?


If you have any questions regarding air compressor oil types, please leave a comment below, with a photo if applicable, so that someone can help you!

By Aidan Weeks

A passionate Mechanical Engineer with endless enthusiasm for fluid power - building off the back of over 18 years of high quality contribution and discussion stimulated by Bill Wade here at About Air Compressors. With both practical and theoretical experience in pneumatics and hydraulics, I'm putting my knowledge to work - and working my grey-matter through my research, assistance and publishing work here at About Air Compressors. Feel free to reach out any time! P.S. A HUGE shout out to Doug who really offers such great value to all visitors to About Air Compressors - once again, feeling like I'm standing on the shoulders of GIANTS by getting to work alongside such a great community

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