6 common kinds of car air filter & how to choose the best one

You’ve owned your car for a while and know a thing or two about wrenching and tinkering around with it. Maybe you’ve been using it as a daily driver, your everyday steed in the grind through life, an occasional weekend car to curve up those mountain roads in either Baguio or in Sagada, or even a track car to quench to race car driver fantasies. Now you’ve decided to upgrade your vehicle’s performance for cheap.

A common setup for a not so common engine

But what to buy and install first?

Today Philkotse.com is gonna talk about one of the first things many a car enthusiast will replace in their beloved vehicles: its air filter.

Now, we all know that a majority of cars today run on combustion engines. Combustion engines function by mixing the air, the spark from your spark plugs, and fuel in order to create miniature explosions that in turn cause your car’s pistons to rapidly rotate your crankshaft.

Now without air, any kind of flame, explosion, or for our purposes combustion, simply won’t exist.

A super clean engine bay in a classic car. A dream for any car enthusiast Note the large, round shaped air filter

Now, just simply letting air into your engine without any kind of filter or protection is bad, very bad. If for some reason you forgot to reinstall your car’s air filter, dirt, and unwanted materials with definitely find their way into your engine causing said engine to lose performance and in some really bad cases, your car’s oil will turn into a thick sludge.

And in the worst cases, your piston rings will need a replacement. That’s exactly what the air filter of a car stops from happening. It stops what smart car people call "abrasive particulate matter" from entering the engine where it would cause all kinds of trouble like those mentioned before; goopy oil and broken piston rings.

Going off road makes your car susceptible to particles making a good air filter a necessity

In your journey to find a new air filter, you come across many kinds, brands and price points of air filters on the internet. Some claiming to provide more horsepower for your car, some others claiming to last longer than the original equipment manufacturer, or OEM ones. Now you’re confused. But don’t worry as confusion after all is a good sign as it is the first step to learning. Now let’s get schooled!

As we’ve said before, there are many kinds of air filters. One of the ways to classify these are according to what they’re made of or how they work. 

>>> Read more: Replacing car air filter: Must-have skills that every Filipino driver needs to know

1. Water Bath

The granddaddy of them all. These air filters were used in many applications, not just cars. Water bath air filters were also used tractors and stationary engines like generators in the 20^th century specifically from the 1900s to the 1930s. Oil bath air filters replaced these later on because the latter provided better performance.

Old cars like this Ford Model A used water bath air filters

2. Oil Bath

Oil Bath air filters function by catching dirt and those abrasive particulate matters in oil. The oil is kept in a sump and an insert made out of a mesh, fiber. Heavier debris is caught in the oil while lighter ones are caught by the mesh.

An old oil bath air filter

3. Foam

Popular for low horsepower applications but horrible for cars because the more dust they catch, the more restrictive airflow becomes.

4. Stainless Steel

These air filters, unlike the common cone shape ones, come in many different shapes in order for you to save space. These come in handy if you’ve already heavily modified your engine and space is has become a premium. Useful if you’ve installed an aftermarket turbo or supercharger.

DNA brand air filter entirely made out of steel

>>> Related: Cabin vs Engine air filter: What are their functions and differences?

5. Paper

The most common material used for automobile applications and to some extent is exclusive to said application. Paper air filters are efficient, single use, easy rip out or install, and easy to find in comparison to the kinds listed above.

A typical paper based air filter

6. Cotton

Cotton air filters are performance air filters that are become more and more popular as high-performance parts. Before it was used as the stock air filter of the Abarth S.S. but today has now been used in many different vehicles around the world.

The kind that you might usually buy to replace in your car’s air filter is the Paper kind because as we’ve said, it is common to find for cheap and very easy to install yourself. But you want something modern and high performance.

>>> Worth to note: 8 telltale signs that you need to replace your air filter

Something other than the run of the mill paper air filter. You might want to consider the most recognizable brand of performance air filter out there; K & N.

Now K&N air filters are made out of cotton which as we’ve already pointed out is for high-performance applications. Now K&N air filters, aside from just being plain old cotton, also use a coat of oil for extra protection against debris without sacrificing added air intake.

A good thing to note about these K&N filters is they are compliant with SAE J726 and ISO 5011 standards. These standards are what major car manufacturers follow with regards to their vehicles. 

Unlike other air filters. K&N air filters are actually more engineered to provide 50% more airflow which in turn makes more power for those little explosions inside your car’s engine. That’s good for you because more efficiency is equal to more power.

A K&N cleaning kit and reusable air filter. Easy to use and environmentally friendly

 K&N filters are also environmentally friendly because unlike the common paper air filter, you can actually reuse the K&N ones more than once. You just need to re-oil the K&N filter with a handy oil spray and you’re good to go.

A thing to remember however to read the K&N air filter manual to know just how much oil you’d want on the air filter. You don’t want it to be dripping wet as that extra oil would flow down to your intake system or affect your electronics system. These air filters are also easy to install as many are designed to be compatible with a myriad of car manufacturer’s existing models.

Be warned though, because as it turns out, a very effective and now popular product can also come with many imitators. So just because they look like, feel, and are priced like the real thing doesn’t mean they’re just as reliable.

As with anything you set out to do with your car, Philkotse.com kindly reminds anyone wanting to go wrenching out there to know the limits of how far you can work on your vehicle. If you know you can’t do it, don’t force it. Thank you for reading and have a good time-wrenching. Peace!

>>> Get more helpful tips and advice for your car maintenance here