Air Oil Separator Vs Catch Can 2023:(Review & Buying Guide)

There is a lot of stigma around Air Oil Separator Vs Catch Can. There are also countless discussions about whether you should get one or the other. But it all boils down to what you can afford and what you need.

In this comparison guide, we’ll cover the main differences between these two useful products.

We will also review both an air oil separator and an oil catch can, that we have found to be among the best products for your vehicle you can find.

By the time you finish reading this comparison guide, you will know precisely whether an AOS or a catch can better serve you.


Air Oil Separator Vs Catch Can: What Are the Differences?

What is an Air Oil Separator?

As you drive down the road, lots of pressure builds up inside the crankcase of the vehicle.

As more and more pressure builds up inside the crankcase, The PCV, which stands for Positive Crankcase Ventilation, relives that stress so that engine will not get damaged.

The pressure must be relieved. However, due to regulations and recent movements to preserve the environment, you cannot vent it out to the atmosphere.

All the pressure goes through the intake, but sometimes, this complex process can lead to oil getting pulled in through the intake, which ultimately lowers fuel economy.

A great way to combat that process is by using an air oil separator.

The air-oil separator prevents the oil from being pulled back into the intake.

The air-oil separator stops all the blow-by that might go through the intake; this is pretty much an automated process.

You don’t need to empty the air-oil separator every so often. All you need to do is install it on your vehicle and never worry about it again.

The air soil separator is also in charge of preventing the PCV oil from frothing inside the PCV.

Without the liquid going through the housing, you would end up with foamy stuff inside the vehicle.

Ultimately the AOS is a worthwhile investment if you want your car to be in great shape for as long as possible.

01. Moroso 85481 Air/Oil Separator


Top 3 Features:

  • Heavy-duty brass inlet/outlet
  • Billet-aluminum body
  • Polished exterior

As an example, we have a powerful air-oil separator from the well-known company Moroso.

Moroso is the best choice for those that need to increase their vehicle’s performance.

Excellent Build Quality

The most noticeable feature of this air oil separator that makes it stand out from other competitors in the market is how well built this model is.

The heavy-duty brass inlets and outlets plus the billet-aluminum body are fantastic.

Straightforward Installation

This model solves the problem most air-oil separators have, which is the installation process.

Nobody wants to spend hours figuring out how to install an AOS on their vehicles, which is why this AOS is so good.

Stable Performance

Not only is this a sturdy and robust AOS, but it also has an excellent mounting bracket to ensure the AOS remains in the same place without it moving all of a sudden.

The mounting bracket is made of stainless steel, which prevents it from rusting away.

What We Liked

  • Stays tightly put on the vehicle
  • The installation is straightforward
  • It is decently easy to clean
  • Improves gas mileage

What We Didn’t Like

  • May need modification for some vehicles

What is a Catch Can?

Air oil separator vs oil catch can both of these products are often confused.

Several vehicles from different brands might experience oil leakage through the PCV.

While the issue might differ depending on the car, it all boils down to the PCV system.

The solution to this annoying issue is an oil catch can. The oil catch can act as a shield that protects the PCV.

It catches all the oil that may enter the PCV system as you drive a couple of miles.

If the oil were to enter the PCV system, the vehicle’s engine could be affected during that process, which is precisely why you want to stop the oil from getting into the PCV system in the first place.

This small piece of tech is installed between the PCV system and the vacuum ports.

Once you have installed the oil catch on the vehicle, the oil catch can catch any oil produced while the car is on.

If the oil catch can indeed catch oil while the engine is running, you can lift the hood up and then drain the oil catch can and watch as oil comes slowly out of the oil catch can.

Using an oil catch can is an inexpensive way to ensure the vehicle performs as it is supposed to run.

Without the reliability of an oil catch can, you run the high risk of oil making its way into the system.

02. Mishimoto MMBCC-MSTWO-BK Compact Oil Catch Can


Top 3 Features:

  • 6061 aluminum can
  • 50-micron bronze filter
  • Universal bracket mount

Some oil catch cans outclass the other ones available, and this model from Mishimoto is one of them.

Precision-engineered catch can

We’re all after those highly-functional catch cans that can take care of our vehicles without having to worry about constant oil getting into the intake of the car.

Mishimoto’s model does a great job of catching any oil that may enter the intake while driving.

Maximum Protection

One of the best ways to ensure you buy the right oil catch can is by taking a look at the materials that were used for the creation of the oil catch can you want to get.

Mishimoto knows this pretty well, which is why they took it to the next level by adding an aluminum baffle to keep all those annoying particles inside the can.

Simple Installation

With so many useful features, you would think this product is hard to install.

But in reality, this installation is super simple, and anybody can install this oil catch.

It comes with a well-explained manual with all the steps required for the installation process.

Compact Design

The people behind this fantastic piece made sure to build a compact yet powerful oil catch can that does not take up much space and fits comfortably inside your vehicle, making it an excellent choice if you’re looking for a small yet strong oil catch can.


And finally, Mishimoto added everything you need for the installation process to make your life easier when setting up this product.

So whether your car has a CCV or PCV, you should be good to go if you got this product.

What We Liked

  • Improves your car’s performance
  • It is super-easy to install
  • The construction lasts a lifetime
  • Cleans up the oil amazingly well

What We Didn’t Like

  • It’s a bit expensive

Air Oil Separator vs Catch Can: Factors to Consider

Air oil separator or catch can what the main difference between these two useful tools is?

In this comparison section, we’ll fully cover all the differences you should know before you get one of these valuable tools.


The most noticeable difference between the air-oil separator and the catch can is the price; the oil catch can is cheaper.

The air-oil separator has a lot more fancy features that inevitably increase the price of this product.

On the other hand, the catch can do not have as many features.

All it does is catch all the oil that might get into the intake. Once it has filled up, you have to drain it.

While it might not be that big of a problem for some people, if you’re short on money or can’t be bothered to spend more money on an air-oil separator, getting an oil catch can is the better choice for saving money.


Both the air-oil separator and the oil catch can keep the system clean to ensure the vehicle performs well.

And while they work similarly, the oil catch can do not drain the oil back into the system, unlike the air-oil separator.

This means you will have to check the oil catch can periodically to make sure the oil is not overflowing the catch can.

You will also have to check the oil catch can if you change the oil. Otherwise, you’ll notice oil leaking from the vehicle.

On the other hand, once you install the air-oil separator, you won’t have to check it.

You simply have to install it on your vehicle, and that’s pretty much it; no maintenance is needed.

High Compression Engines

One of the most critical factors you want to consider when choosing between the air-oil separator and the oil catch can is how much oil your car burns.

Oil catch cans have to be drained manually, which can be inconvenient if your car burns too much oil.

You will have to check the catch cans pretty often and drain all the oil inside them before the oil starts leaking.

With air-oil separators, you do not have this problem.

The air-oil separator will put back all the oil into the system so that it won’t get into the intake, and you won’t have to drain it manually.


What is the difference between catch can and air-oil separator? The main difference between these two is that the air oil separator runs coolant.

This is super useful as all the oil that is caught is more likely to foam up.

If the oil ever foams up, the air-oil separator will melt it, and then it will go back into the engine. Unfortunately, oil catch cans cannot do this.

People Also Ask About: Air Oil Separator vs Catch Can

Are you feeling a little bit lost and feel like you need more guidance on both the air-oil separator and the oil catch can?

If so, here are some common questions you might find helpful:

Are oil catch cans necessary?

If you have a healthy engine, you do not need an oil catch can.

However, if you have a poor engine and it’s leaking oil — you should get an oil catch can to prevent the oil from ruining the engine in the long run.

Can an oil catch Can increase performance?

Suppose your engine is continually leaking oil, and the car’s performance is being affected by it.

In that case, the oil catch can significantly increase the vehicle’s performance, as the oil won’t affect the engine itself.

How does a catch can work?

Think of it this way: the catch can essentially act as a cup; it catches all the oil that that goes through the PCV.

With the catch can, you’re essentially protecting the engine. Once the catch can fill up, you have to drain all the oil inside the catch can.

Do you need an oil separator?

If your engine is working perfectly fine, you don’t need an oil separator.

However, if that is not the case, then an oil separator is going to prevent the oil from getting pulled in through the intake.

If you’re hearing a knocking sound coming from under the hood, then an oil separator will reduce the octane of the fuel.

Where is an air oil separator installed?

Air oil separators do not take up much space as they are installed between the PCV system and the vacuum ports.

How to clean an oil separator?

Here is how you can clean your oil separator like a professional:

  • Remove the oil separator from the vehicle
  • Spray it with brake cleaner to clean the impurities inside the oil separator
  • Get a rag and wipe it off
  • Now put it back in the vehicle


Air oil separator VS Catch can both of these oil catch products improve the vehicle’s overall performance, which is always nice to have.

Without them, your engine might be affected by all the oil getting inside. Not all cars need an air oil separator or a catch can.

If your engine is working fine and you have not experienced anything that might suggest an oil leakage, you don’t need any of these products.

You will get by just fine without them.

However, if that is not the case, you should consider getting an air oil separator or a catch can. Either one will serve you well. is a participant of the Amazon Affiliate program. We may earn a small commission if you purchase through our recommended links. More details.

Leave a Comment