How Often Should You Change The Air Filter in Your Car?

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How Often Should You Change the Air Filter in Your Car

Everyone who owns a car knows that by taking great care of all of its components, you can not only expect longer service life but greater performance too. This is equally true of all parts, including the air filter. Its purpose is to allow the exact amount of clean air into the engine to mix with the fuel, this then burns to give the power to run the vehicle. Dirty air clogs everything and may make your car run roughly.

By not changing the air filter at regular intervals, you could lead yourself into many problems, mainly reduced fuel economy and decreased horsepower.

Knowing when to change the air filter is not an exact science, there are many factors to take into consideration.

While some experts suggest every 3,000 miles, others think this too excessive. If you drive in the busy city daily and are regularly stopping and starting your engine, you are obviously going to need more frequent filter changes. Much more frequent than the proverbial Sunday driver who gets the car out once a week to visit the store. Somewhere between 15-30,000 miles is usually the average, or every 2 years, whichever hits first. Most people have it done annually, along with their oil change. The best practice is to visually check your air filter at 6 monthly intervals. If it looks dirty, change it.

You could save yourself problems and greater expense further down the road.

In this article, we are going to discuss How Often Should You Change the Air Filter in Your Car? So, let start with some basic information.

How Does An Air Filter Work?

Every single tiny molecule of air that enters your car’s engine will have passed through its air filter. Valves and pistons combine energy to suck in air and send it to the combustion chamber. Here is where the oxygen, in particular, is mixed with the fuel, either gas or diesel. The spark plug ignites the mixture and creates a boom effect. This is where the power comes from to start and run the engine. The ratio of air/fuel has to be exact. Too little air makes the mix ‘rich’ and may cause your car to run rough and lose power. A clogged, dirty filter won’t allow enough air through. The only air your engine wants is the purest form. Otherwise, along with performance and fuel economy issues, you might get particles that settle on metal components in the engine. They become abrasive and can cause damage as they wear away at parts. This could result in high-cost repairs that are unnecessary and could have been easily avoided.

Signs That Tell You it’s Time to Change Your Air Filter

The simplest way to check is to take a look at it. If it appears dirty and dusty then for the sake of a little time and at a relatively low cost, you should change it. A clogged up air filter will cause harm to your car.

Otherwise, your car itself will tell you that it is time to replace the air filter.

IGNITION ISSUES: If your vehicle is making sounds you don’t recognize or has developed a misfire, it may not be your air filter but equally, it may, it won’t harm anything to check even just to rule it out.

WARNING LIGHT: The engine check light may come on on the dashboard or you may notice a heavy gasoline odor when you crank the engine. This is usually a sign that the mix is too rich and the filter has seen better days. If the tailpipe is kicking out black, sooty smoke, this is another warning sign.

DECREASED POWER: If your car has a sluggish feeling and seems to be driving ‘heavy’, this is a sign of reduced horsepower, no pull, another symptom of a worn-out air filter.

REDUCED MPG: Finally the most common and most annoying issue. If your vehicle isn’t getting the airflow it needs, it will have to work harder. This will drain your fuel quicker, reduced fuel economy. Are you getting fewer miles than usual from a tank of fuel? Check the air filter! An air filter in desperate need of change will undoubtedly affect your car’s performance.

How to Change an Air Filter?

This is one of the easiest auto maintenance jobs there is. So next time you go to get an oil change and the mechanic tries to bully you into letting him change your filter, don’t let him. He may charge you $30 or $40 for a job that takes 2 minutes for you to perform at home!

  • Firstly, make sure the engine is cool and pop the hood.
  • Locate the air filter housing, it’s usually a fairly big black box, but it differs from 1 car to the next.
  • It will simply unclip allowing you to see the filter. Note which way up it is and remove it.
  • Then slot the new filter in, in exactly the same position as the old one.
  • Clip the housing back into place and that is it. Job done.

Time at the garage and money saved quite a result.

Are all Air Filters for Cars The Same?

Air filters are principally the same, material designed and folded in such a way to keep dust from your engine. They differ in the materials from which they are fabricated.

Paper air filters

The most common type of air filter and usually the stock filter that is put on the car on the production line. It is very similar to paper but is a little thicker, made from wood pulp. This is folded over and over until it resembles a concertina to give it a greater surface area. Imagine if the filter consisted of one piece of fabric stretch over a plastic frame. That would soon become clogged and require changing more frequently. The accordion style helps trap more debris allowing for longer intervals between air filter changes.

This is then attached to a foam square and is framed to make it sturdy. Obviously cheap to make but still effective. The average life span of a paper air filter is anything between 10,000 and 20,000 miles

Cotton air filters

This looks very similar to the paper filter and adapts the same concertina style. This time cotton and aluminum mesh are layered giving a less dense feel than paper. The air can penetrate through more easily resulting in a noticeable power increase. If cleaned and cared for properly, these can last as long as the car. This means they are the more expensive big brother of the paper filter.

Foam air filters

Even more, the air still can get sucked through the tiny holes that are formed during foam fabrication. While this may add power to your car, it also means that there is more opportunity for dust to get sucked into the engine. Experienced auto enthusiasts like to use foam with an added layer of oil to act as a barrier against dirt.

Metal air filters

Made from very fine layers of stainless steel mesh, these filters look good and are durable. They are less restrictive than the cotton or foam designs, they allow more air through. The filtration will be affected slightly but not enough to cause any damage. As will all air filters, regular changes will prevent this. The size and shape may differ, depending on the make and model of your vehicle. If you’re unsure of which you need just check your car’s handbook or ask at the parts store. Different brands are available too, with varying prices. If you are going to be driving in polluted and smoggy conditions then it’s worth investing in the best that you can afford. If you rarely get the car out and have a new filter once a year at every oil change, then a basic one should do.


We’re a little cash strapped at the moment, is it possible to clean the existing air filter?

Absolutely. You won’t get the same performance that you could expect from a new air filter, but it will definitely improve things until you can afford to replace it. Once you have located and removed the air filter, the easiest way to clean it is to use the vacuum. Tap off any debris against the bumper, then use the nozzle to carefully vacuum away as much dirt as you can. Return it to its housing and you’re good to go.

You can use a cleaning solution on it but you must ensure that the filter is 100% dry before replacing it. Any moisture in the engine can cause serious problems.

My aunt drives less than 10 miles each week, surely we won’t need to change her air filter?

If you want to keep the engine protected and the car running smoothly, you will. Stock filters have a life of around 3 years, after which they become brittle and break down. Those pieces could find their way into the combustion chamber, contaminate the oil and greatly shorten the engine’s life.

How much money will I save if I change my air filter myself?

This depends on where you are and the make and model of your car. Also if the mechanic can easily get to the air filter housing without much of a struggle. Most places charge between $20 and $50, that’s to supply and fit. Depending on which brand and style of filter you choose, they can cost just a few dollars. Doing the simple task yourself is well worth it.

The air filter in my car has got wet, should I be concerned?

If it is slightly damp from a little excessive rain then there is no real reason for concern. The engine is quite a robust thing and will cope with it. However, if it is absolutely soaked through from being submerged or from a different issue, you should remove it and thoroughly dry it out before starting the car. The moisture may cause the engine to choke and the mix to run too rich.

Changing The Air Filter Really Can Improve Car Performance

Think of your car as a body, trying to suck in the clean, fresh air. You would cough and splutter if dust went into your mouth much as a car does. It feels suffocated with a clogged air filter. By fitting a new one you are allowing your engine to get maximum airflow. More air equals better performance. If greater fuel efficiency increased performance, and not having to change your air filter appeal to you then consider a High Flow Air Filter.

They don’t need to be changed but do need to be cleaned every 2 years and are obviously more expensive. More air is pulled in which can increase horsepower by 3-5%, torque will improve too. The higher end of the range ones also include a cold air pipe which doesn’t use the warm air from around the engine but sucks cooler air from outside. Cold air is less dense and therefore burns better and allows the fuel use to be more efficient, between 6% and 11% more efficient. No one would complain about gaining a few extra miles from a tank of fuel, surely? All good things come at a cost though, some HighFlow filters have sacrificed the ability to filter out as many contaminants, and some let in moisture. This can be overcome by using barrier oils that act as a shield.

In Conclusion

How often you should change the air filter in your car differs from 1 vehicle to the next. So many variables to consider such as the conditions we drive in, whether you’re lucky enough to live in a sleepy out of town place or in a built-up, pollution-filled city. We recommend that a 6-monthly visual check of your air filter is the best piece of advice. Otherwise somewhere between 15000 and 30000, driving conditions are considered. Changing the filter with each oil change is also a good idea, whether that’s annually or every second year. Don’t forget, please don’t pay someone over the odds to change it for you, do it yourself, it’s as easy as pie!

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