Quick Facts About Car Air Filters
- You don’t need to replace your car’s air filter every time you get an oil change.
- A disposable engine air filter is good for about 15,000 to 30,000 miles, depending on driving conditions.
- Changing your car air filter is one car maintenance job that is easy enough to do at home.
The engine air filter in your car keeps contaminants out while providing the air it needs to run. Keeping this filter clean gives you optimal engine health, performance, and efficiency. A filter clogged with excessive dirt and debris will sap acceleration and worsen fuel economy.
So, how often should you replace this vital car filter? We’ll provide details and more.
- What Is a Car Air Filter?
- When Should You Replace a Car Air Filter?
- Can I Replace the Car Air Filter Myself?
- Signs of a Bad Car Air Filter
- What About Reusable Car Air Filters?
What Is a Car Air Filter?
A car air filter prevents dirt, debris, and other pollutants from entering the engine. As you drive in heavy traffic, over gravel, and other daily driving, all the air containing pollution and dirt is pulled into the vehicle. Luckily, the filter only allows clean air to make its way to the engine before combustion, improving fuel economy and performance.
Like most air filters, it traps all the particles mentioned above, which will cause the filter to turn from white to a much dirtier appearance over time.
Car Engine Air Filter vs. Cabin Air Filter: What’s the Difference
Because your car operates with two primary air filters, we’ll explain how your engine air filter differs from your cabin air filter.
Car engine air filter: This filter protects your engine from damaging material entering critical components and its efficiency, as explained above.
Cabin air filter: This filter you’ll replace more often (1 to 2 times per year), and it keeps the cabin air flowing clean and free of allergens, dust, mold, and other contaminants.
When Should You Replace Car Air Filter?
Different car manufacturers offer different recommendations on how often you should change your car’s air filter. Still, there’s a consensus that a disposable filter is good for 15,000 to 30,000 miles, depending on driving conditions.
If you drive in particularly harsh conditions (e.g., heavy traffic in hot weather, unpaved roads, or frequent off-roading), change your filter more often, or about 15,000 miles between replacements. Remember to keep track of all service records to help clarify when your air filter was last replaced.
Some shops might try to talk you into getting a new air filter with every oil change, but that’s far too often. It might not seem like a big deal since air filters are usually pretty cheap, and replacing them isn’t a big job, but a polite “no thanks” can help you avoid getting a new one when it’s unnecessary.
Can I Replace the Car Air Filter Myself?
Yes. This is one car maintenance job that is easy enough to do in your garage. Most engine air filters are straightforward to access under the hood or in the glove compartment inside the vehicle. If you’re unsure where it is, consult the owner’s manual to clarify where and how to replace it. If you’re having difficulty finding the information you need in the manual, check for it online. A quick search using your car’s year, make, and model should give you the answers you need. Reviewing the manual or consulting the web will also tell you the part number for the filter to use in your engine.
Start by opening the air box by removing a few screws with a screwdriver (or sometimes with no tools). When the airbox opens, you’ll see either a flat, rectangular filter or a round, cone-shaped filter. A flat filter can usually be removed by hand, and a cone-shaped filter will usually be secured with a hose clamp that can be loosened and tightened with a screwdriver. Simply take out the old one, put in the new one, close the airbox back up, and it will be good for the next 30,000 or so miles.
It doesn’t hurt to do a quick visual inspection of the air filter you’re currently using if you’re not sure how long it’s been since you’ve replaced it. You don’t have to be a mechanic to spot an air filter that needs replacing. If it looks filthy and worn out and you don’t know how many miles are on it, it’s better to be safe than sorry and replace it, especially since it’s a low-cost maintenance item, and replacing it early doesn’t hurt anything.
Signs of a Bad Car Air Filter
While it may be hard to tell when to replace your engine air filter since you don’t see it daily, there are a few warning signs that it may be time. While you can always take a look at it, most of the signs you’ll be able to notice just by paying attention to your vehicle.
- The engine air filter is visibly dirty
- Reduced gas mileage
- You haven’t replaced it in over a year
- Reduced acceleration
What About Reusable Car Air Filters?
Some high-performance aftermarket air filters from brands like K&N and Injen claim that they’re suitable for the life of your car but need to be cleaned every so often to remain effective. These filters use more durable materials than regular disposable air filters, proving that replacement isn’t necessary. They also claim that improving airflow improves engine performance without sacrificing proper air filtration.
If you use a reusable air filter, clean it as often as the filter manufacturer recommends. Some aftermarket brands even offer a cleaning kit specifically designed for their air filters. Keeping that kit in your garage is not a bad idea to ensure you use safe chemicals on your filter.
It’s safe for most drivers to go about 30,000 miles between air filter replacements. If you’re driving in harsh conditions that throw a lot of dirt and debris at your car, you’ll want to adjust that number to about 15,000 miles, particularly if you go off-roading. If you’re using a reusable aftermarket filter, follow the manufacturer’s instructions closely on how to keep it clean and effective.
Editor’s Note: This article has been updated for accuracy since it was originally published.
