How Often Should You Change Your Car’s Air Filters?

You probably don’t think about your car’s air filters very often. You might not have even known your car has them. Maybe you’ve seen them while the technician at the oil change does their upcharge pitch, along with the “different colors of transmission fluid’ routine.

You probably don’t need to spend money on transmission fluid that often. But your car’s air filters are vital to your health, and the ‘health’ of your car.

Have you ever wondered how air gets into your car with the windows up? There’s an air intake which allows air to flow into your car’s passenger space, or cabin. Even if the AC is set to ‘recycle’ some air is usually let in. The highway is a dirty place. And if you’ve ever driven on a dirt road, you know the amount of dust can be huge. Your car’s air filter cleans all that stuff out of the air before it blows through your vents.

Just like you, your car needs to ‘breathe.’ The engine uses oxygen in the open air, mixes it with fuel, and sets off thousands of little explosions a minute to keep your car moving forward. To work at its best, your engine needs as clean of air as possible. Dirt and other outside contaminants can, over time, hurt your engine and lead to expensive repairs.

The good news is that cabin and engine air filters are pretty simple to inspect and replace. Some can even be washed and reused! Just how often you need to check your filters depends on a number of factors.

The number of miles on your car is one good indication. However, the kind of conditions you drove those miles in is just as important to filter longevity. 5000 miles on a highway may equal 100 miles on a dusty country road.

Below we offer you some tips on how to check your filter and when to replace it.

What Do Car Air Filters Do?

Most cars come with two air filters, one for the passenger cabin and one for your car’s engine. Both are important, so keeping tabs on their condition is vital for a clean, comfortable and operational car.

Filters are made out of a number of materials which can ‘breathe.’ That’s another way of saying they can let air through them. Special paper, cotton, or foam all are such materials. These filters keep sand, dust, fumes from other vehicles, pollen, and other particulates from entering your lungs or your engine.

Engine Filters

If dust, sand, or outside chemicals are allowed to enter your engine, they can easily reduce your engine’s efficiency and performance and cause lasting damage to pistons and cylinder walls.

Cabin Filters

The road is a dirty place filled with all sorts of pollutants, including the exhaust coming out of the tailpipe of the car in front of you. These are the same pollutants that contribute to the deaths of millions of people annually. Repeated and prolonged exposure to this pollution is almost as bad as smoking and can lead to serious cardiovascular and respiratory problems.

Clean cabin filters are usually very good at removing these pollutants. HEPA-type filters can stop 90 percent, or higher, of all particulate matter .3 microns and bigger (that’s really small).

How Often to Change Engine Air Filter

Unlike other parts of your car, there are no set rules on when you should change the air filters. It’s also unlikely that a dirty filter will cause your check engine light to come on. So it’s important you keep track of them yourself. Below are some helpful tips to do that.

Driving Distance

How far you have driven your car is a big factor. Under ideal conditions, you should check and replace your filter every 30,000 miles.


But if even your car just sits in your driveway, the material from which it is made can become brittle and less absorbent over time. So you should also check your filters every three years.

Your Vehicle’s Model

Each car company has different recommendations for filter replacement based on their specific models. You can usually find these in your owner’s manual. Ford may recommend replacement every 30,000 miles while Chevy recommends 45,000 miles.

Driving Conditions

Where you drive has a huge impact on your filters. Unpaved, dirt roads can allow dust or sand to build up rapidly. Streets with heavy congestion can pump a lot more pollutants into your filter than driving your car on the interstate. Hot weather also tends to wear down your filter. For that reason, Hyundai recommends changing your filters every 15,000 miles in these types of conditions.

Signs Your Filter Needs to be Changed

If you’ve bought your car used, or if you’ve just lost track of how many miles between filter changes, here are some signs to look for that tell you your filter may need to be changed.

1. Reduction in Power

A stopped up engine filter can cause ignition problems. it can also decrease your acceleration ability by six to eight percent. This will make your car feel sluggish. This will happen over time so it might not be as noticeable as some other signs.

2. Visual Inspection

Just looking at the filters can tell you if you need to change them. Heavy soot or layers of dust are clear indications that you need to switch them out for new ones. It’s easy to tell since new filters are white. This is usually when the mechanic at the oil change will show you your filter. You may not need to change it every time, but it’s a good time to visually inspect it.

3. Black Smoke

Here’s some engine chemistry. An engine needs approximately 2,641 gallons of air for every 1.3 gallons of gas to work most effectively. If the engine doesn’t get all that air, then it won’t burn as much fuel. The unspent fuel will come out of your tailpipe as thick black smoke. That’s a clear sign that your engine needs more oxygen and that your filter may need changing.

How Often to Change Cabin Air Filter

Typically, cabin air filters should be replaced on a yearly basis or every 12,000 to 30,000 miles. But the conditions impacting the engine filter described above also impact the cabin filter. Here are some signs your cabin filter needs changing:

Bad Odors in the Cabin. Anything from fumes from other vehicles to the road kill you just drove past. Yeah, that’s disgusting.

Lower airflow or your AC not working as well as it should.

Louder than normal air circulation.

Allergies or asthma flare-ups when you get in the car.

How to Change an Air Filter

Unless you are a car DIYer, a mechanic or car dealership can easily replace your filters. However, as with anything having to do with car repair, it will cost you less to do it yourself.

Engine Air Filter

This filter is usually found under the hood and is easy to reach. Car designers try to keep these up off the road so they are usually accessible from the top of the car. The filter will be in a filter box. You can easily open the box, either with a latch or a simple screw driver, depending on the model. A quick search on the internet will show you the model/type of filter your car needs.

Cabin Air Filter

Your cabin filter may be a little harder to reach since it’s usually under the dashboard and maybe behind the glove box. (Cause that’s where your AC vents are). But once you understand the process, it’s usually a simple task.

Summing Up

Your cabin air filter allows you to breathe easily while driving through some pretty dirty places. And just like your body’s lungs, your car’s engine needs oxygen too. How often you need to change these filters depends on road conditions, time, and the model of your car. Your car will give you signs that it’s time to replace the filters.

Some filters are designed to be reused after cleaning. If you do have a one-time use filter, you can recycle it at your dealers.

It’s pretty simple to replace the filters yourself, but if you don’t have the time or aren’t mechanically inclined, any mechanic can do it for you.

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