Air Filter Buyer's Guide
- Automotive air filters protect both the vehicle and its passengers from harmful air contaminants.
- An engine filter regulates and decontaminates the air that flows from the cold air intake system towards the engine.
- Clean air is extremely critical to optimize fuel burning in an internal combustion engine.
- In older vehicles, missing the filter is improbable because it is a large round piece that sits on top of the carburetor. Most modern filters either come in the form of a cone or a rectangular panel.
- There are two main types of engine air filters—dry and oiled performance filters.
- The cost of an automotive air filter will vary depending on your vehicle’s specific year, make, and model. OE replacement air filters will generally cost you anywhere in the range of $5 to $410. They are sold either individually or in sets of two or more.
- Have your air filter checked every time your vehicle gets an oil change. You should have these checks annually or every 12,000 miles. You may have it checked earlier if you frequently drive around areas that are dusty or have a lot of road debris.
What are automotive air filters?
Just as humans require fresh air to keep all critical body systems running smoothly, your vehicle requires clean air to run at optimal performance. Automotive air filters protect both the vehicle and its passengers from harmful air contaminants.
There are two common types of air filters that you would see in a vehicle. The term air filter usually refers to the engine air filter, otherwise known as an internal combustion air filter. The other kind of air filter is known as the cabin air filter.
What’s the difference between a cabin air filter and an engine air filter?
Cabin air filters, also called air conditioning filters, filter the air that comes from your outside air intake. They improve air quality inside the vehicle filtering out dust, pollen, and other pollutants. Replacing a bad cabin air filter is mostly done for safety and health purposes. Replacing this component doesn’t impact vehicle performance.
The engine air filter is designed to regulate the quality of air that flow to your engine. Its main role is to protect the engine from contaminants that may interfere with efficient fuel combustion. Replacing a failing engine air filter will generally improve vehicle power and performance. While these two types of filters are both essential to the operation of a vehicle, this guide will focus on engine air filters.
What is an engine filter?
An engine filter regulates and decontaminates the air that flows from the cold air intake system towards the engine. Just as how oxygen is needed to start a fire, sufficient clean air is extremely critical to optimize fuel burning in an internal combustion engine.
In older vehicles, missing the engine air filter is improbable because it is a large round piece that sits on top of the carburetor. Most modern filters either come in the form of a cone or a rectangular panel. They are usually made from a disposable paper material or reusable wire-wrapped cotton, and are installed in front of the engine compartment inside a cold air collector box.
To learn more about what can happen when your car’s engine air filter is dirty, read our article.
How does an engine air filter work?
All internal combustion engines need air to burn fuel. Cold air from outside the vehicle is ideal for maximum power and performance because of its higher density. The air intake system is located directly behind the grille of a vehicle. As vehicle the vehicle runs, air passes through a tube that is connected to the air filter housing. The engine filter inside this box traps dirt and airborne contaminants before allowing the air to flow towards the engine.
What are the types of car air filters?
There are two main types of engine air filters—dry and oiled performance filters.
Dry or paper air filters
Dry filters, also known as disposable paper filters, are made from thick fibers that are compressed to create a dense filtration surface. Their construction makes them more restrictive with airflow, effectively minimizing contaminants that may harm your engine. Most vehicles come with an OEM paper filter that can get blocked and will require replacement over time.
Oiled or reusable air filters
On the other hand, oiled air filters are made from oil-treated high flow cotton. Instead of a dense surface for filtration, they rely on the oiled surface to trap dust. Oiled air filters are a great option for drivers who want to improve engine performance by increasing air intake. These filters are washable and reusable, giving them a longer lifespan than dry paper air filters.
How much does it cost to replace an air filter?
The cost of an automotive air filter will vary depending on your vehicle’s specific year, make, and model. OE replacement air filters will generally cost you anywhere in the range of $5 to $410. They are sold individually or in sets of two or more. Changing an air filter is a quick fix that you can do on your own or with the help of a licensed mechanic.
What are the symptoms of a bad air filter?
Here are eight common signs that strongly indicate the need for an engine air filter replacement.
1. Check engine light switches on
Inadequate air supply to the engine results in an increase in carbon deposits which can trigger the Check Engine Light. This warning light can be activated by a variety of engine problems, so it is best to consult a trusted mechanic to accurately diagnose your vehicle.
2. Strong fuel scent when starting the car
The lack of clean air inside the engine can mess your air-to-fuel ratio up, resulting in an excess of unburnt fuel in the engine. If you smell a strong gasoline scent emitted from your exhaust pipe while starting your vehicle, it’s likely that there is an issue with the engine air filter.
3. Visible dirt buildup on the air filter
Knowing when to replace your car air filter can be as simple as checking under the hood and taking a peek inside the air filter housing. New filters typically come in light colors such as white to make it easier to check if it needs replacing.
4. Higher fuel consumption than usual
Reduced fuel economy is another common sign of a dirty or damaged air filter. An imbalance in the air and fuel mix will make the engine work harder to produce the same level of performance as it does with a clean air filter. A modern engine needs approximately 10,000 gallons of air to burn a gallon of fuel.
5. Slow acceleration
A lack of air in the engine can result in up to an 11% loss in horsepower. If your car is slow or jerks upon acceleration, it may be time to replace your engine air filter.
6. Misfiring engine
Carbon deposits may accumulate on the spark plug as a result of an imbalance in the engine’s air-to-fuel ratio. These deposits will make it harder to ignite the fuel, resulting in difficulty starting up your vehicle.
7. Soot or black smoke from the exhaust
Another sign of a bad engine air filter is black soot coming out from the exhaust pipe of a vehicle. This happens when the engine is starved for air and runs ‘too rich’ which means there is an excessive amount of fuel left unburnt, creating byproducts that are released via the exhaust.
8. Coughing or popping engine noises
A damaged spark plug due to a dirty or damaged air filter can cause your vehicle to vibrate excessively or make unusual noises while starting your engine..
How often should you replace the engine air filter?
To keep your vehicle running in top condition, you’ll have to know how often to change air filters in your car. A good rule is to have your air filter checked every time your vehicle gets an oil change. You should have these checks annually or every 12,000-45,000 miles. You may have it checked earlier if you frequently drive around areas that are dusty or have a lot of road debris.
Use our website’s search feature to find the right air filter for your vehicle. To narrow down your search, simply type in your vehicle’s correct year, make, and model to browse through compatible parts.
If you notice oil in your air filter's housing while changing your filters, you may read our article, "Why Is There Oil in My Air Filter Housing and Air Intake?".
How to Choose the Right Engine Air Filter
In modern automobiles, the air undergoes filtering before it enters the engine cylinders to prevent abrasive particles from causing mechanical damage. The engine air filter takes care of this task. Without air filters, foreign particles may strain and damage the engine.
But air filters, just like everything else, can’t withstand harsh environmental conditions. Eventually, they need replacement to keep your car in peak condition. Poor gas mileage and ineffective emissions control system are some symptoms of worn air filters. If you want to buy a new filter, there are some things to remember so you will not regret your purchase.
Which type of air filter is best for my car?
There are different types of air filters to help improve your car’s performance. Listed below are the different types that you can choose from if you’re looking for a new air filter.
Paper: Because they are cost-efficient and effective, paper filters commonly appear in factory automobile assemblies. Made from industrial-grade paper, they undergo a folding process to trap dust and debris. Though paper filters are cheap, they often need replacement.
Foam: Made from polyurethane foam soaked in oil, foam filters are perfect for off-road drivers because of their excellent filtering capacity. Although foam filters are thick and reusable, they disintegrate over time and clog engines.
Cotton: Oil-wetted cotton gauze comprises high-performance filters for race cars because it increases an engine’s air intake. But because cotton filters are high-performance upgrades, they are expensive.
Helpful tips in replacing your car's air filter
Automobile air filters usually need replacement every year or every 12,000 miles that your vehicle travels. So, after you install your new air filter, note the date and the odometer reading of your car. Once 12 months or 12,000 miles have passed, it’s time to look for a new filter.