Have you ever seen pictures of what tobacco smoking does to the lungs? Mechanics can show you pictures of dirty car filters that are just as scary.

Behind-the-wheel driving lessons teach you about what’s inside the car, but you have to also know what’s under the hood. A car engine can’t work properly without clean air, oil and fuel. The engine is kept clean by filters that are able to keep out contaminants while letting clean air and liquids pass through. 

There are four kinds of car filters that are used in almost every vehicle:

• Air filter

• Cabin filter

• Oil filter

• Fuel filter

Knowing how these filters work and when you should change them is an essential part of driving and maintaining your vehicle. Dirty filters can lead to serious mechanical problems over time that are easily preventable. Let’s take a closer look at each type of filter, what it does and how to change them yourself. 

Air Filters: Cleans the Air Used by the Car Engine

If you’ve seen an older car with its engine sputtering and puffing out black smoke, it could be due to a dirty air filter. Long before a newer car starts puffing smoke, the check engine light will come on because the air filter is past its prime.

An air filter is a very simple component in the air intake that’s able to keep the air going into the engine clean of contaminants. The screen keeps out bugs, water, road grime, pollen, dirt and everything else that blows into your vehicle’s grill. 

The air filter is one of the simplest parts to change or clean. You can remove the intake hose attached to the air collection box and lift out the filter. Hold the filter up to the light. If you can’t see light through it, you should clean or replace it.

Cabin Filters: Purifies the Air in the Vehicle

Whether or not you’re using the air conditioner, the cabin air filter keeps dust, pollen and other air pollutants out of the air you breathe while driving. The cabin air filter is part of the ventilation system. This rectangular screen keeps a number of things out of the air inside your car:

• Exhaust fumes

• Dirt

• Dust

• Pollen

• Bugs

• Leaves

In addition, the cabin air filter prevents all this gunk from clogging up the vehicle’s AC system.

The cabin air filter can be under the hood, behind the glove compartment or under the dash. Depending on its location, cabin air filters can be slightly more challenging to replace than the engine air filter. 

Oil Filters: Clean Lubrication That’s Critical for Engine Performance

Oil is needed to lubricate the many engine components that work together to make a vehicle run. Without oil the engine would quickly overheat and parts would wear out prematurely. But every time oil circulates through the engine it can become contaminated. 

The oil filter keeps debris and dirt out of the oil while the engine is running. A properly-working oil filter is critical to your car’s smooth operation, engine life and fuel mileage.

If you can change your oil, you should be able to replace the oil filter. Plus, it’s best practice to replace the oil filter every time you change your oil. You may need to change the oil and filter every 3,000 miles but many newer vehicles require less-frequent changes up to 10,000 miles.

Fuel Filters: Clears Out Gas Contaminants 

When fuel comes out of a refinery, it’s clean. Then it goes into trucks and gas station tanks where it may get contaminated before it goes into your vehicle. The fuel filter keeps dirt, grime and water out of your engine.

The fuel filter is a cartridge located in the fuel line. Inside the cartridge, there’s a screen that catches dirt, rust and other debris in the fuel before it passes through to the fuel injector.

When it’s time for a fuel filter change you may notice that your vehicle is more sluggish than normal or it’s suddenly misfiring for no reason. Most manufacturers recommend that you change the fuel filter every two years or 30,000 miles, whichever comes first. Follow your car’s manual to know when to change the fuel filter for ideal performance. Some fuel filters are located inside the car’s gas tank and it can be difficult to change yourself.

All four kinds of car filters keep your car running smoothly so you can drive safely and worry-free. When in doubt, always refer to the guidelines in your owner’s manual. There will be a section on what maintenance measures (like changing filters) need to be taken and when.

*This article was updated on 6/4/2020