Home FAQ

What happens if you dont change the air filter in your car?

A car that goes without replacing its air filter can lose power and efficiency, and in the long run may suffer more maintenance issues. The cabin air filter, if neglected, mainly degrades interior air quality and HVAC performance.

Engine air filter: how neglect affects performance

The engine air filter keeps dust and debris from entering the intake. When it becomes clogged, the engine receives less air, upsetting the air‑fuel balance and forcing the engine to work harder to compensate.

Common symptoms you might notice if the engine air filter is overdue include:

Decreased horsepower and slower acceleration

Lower fuel economy and higher running costs

Rough idling, misfires, or occasional stalling

Increased engine deposits, spark plug fouling, or exhaust soot

Higher emissions and potential damage to the catalytic converter over time

Possible check engine light or trouble codes in some cases

In short, a dirty engine air filter can throttle performance, raise fuel costs, and increase emissions, with longer-term risks if left unresolved. Replacing the filter is a simple, affordable fix.

Cabin air filter: interior air quality and comfort

The cabin filter protects the interior from dust, pollen, and odors. When it becomes clogged, the HVAC system has to work harder to move air, and the air quality inside the vehicle can deteriorate.

Symptoms that the cabin filter needs replacement include:

Reduced airflow from the vents, especially at higher fan speeds

Musty odors or stale air inside the cabin

Increased allergy or respiratory symptoms for occupants

Difficulty in achieving or maintaining the desired cabin temperature

HVAC noises or longer running times to reach comfort levels

Keeping the cabin filter fresh helps maintain clear airflow, improve comfort, and reduce odors and allergens inside the vehicle.

Maintenance basics: when and how to replace

Regular replacement intervals depend on driving conditions, but general guidelines apply to most passenger cars.

Typical replacement intervals by the book for most cars are:

Engine air filter: every 12,000–15,000 miles (about 19,000–24,000 km) under normal conditions; more frequently in dusty or harsh environments.

Cabin air filter: every 15,000–30,000 miles (about 24,000–48,000 km) or roughly once a year, depending on usage and environment.

If you regularly drive on dusty roads, in heavy traffic, or do many short trips, you may want to check filters more often and replace them sooner. Always refer to your vehicle’s owner manual or consult a technician for guidance tailored to your model.

Summary

Swapping in fresh air filters is a small, inexpensive preventive step with outsized benefits. A clean engine air filter helps maintain power, efficiency, and emissions, while a fresh cabin filter preserves interior air quality and HVAC performance. By following the recommended replacement intervals and considering your driving conditions, you can avoid common problems and extend the life of your vehicle.

What happens if you haven't changed your air filter in 2 years?

If the air filters are not changed and the issues continue, the long-term effects could be respiratory diseases, heart disease, or cancer.

What happens if you drive your car with a dirty air filter?

Driving with a dirty air filter can lead to decreased fuel efficiency, poor acceleration, and reduced engine power. It can also cause engine misfires, rough idling, a clogged or completely blocked filter may even cause the engine to overheat or fail to start, and in the long term, it can lead to engine damage by allowing particles to enter the combustion chamber.

This video explains what happens when you drive with a dirty air filter: 1mproclaimliberty2000YouTube · Aug 26, 2017
Immediate effects

Reduced performance: The engine receives less air, leading to sluggish acceleration, a loss of horsepower, and overall weaker performance.
Decreased fuel efficiency: The engine tries to compensate for the lack of air by using more fuel, which is often not fully combusted, wasting it and increasing fuel consumption.
Rough engine operation: A dirty air filter can disrupt the air-to-fuel ratio, causing the engine to misfire, idle roughly, or even stall.
Other symptoms: You might hear unusual engine noises, smell a strong fuel odor, or see black smoke from the exhaust.

Potential long-term damage

Engine damage: Over time, fine particles can bypass the clogged filter and enter the combustion chambers, causing premature wear on components like pistons and cylinder walls.
Check engine light: The vehicle's computer may detect the abnormal air-to-fuel ratio and trigger the "check engine" light.
Engine overheating: In extreme cases, a severely clogged filter can cause the engine to run too hot, potentially leading to overheating.

You can watch this video to learn about the symptoms of a dirty air filter: 36sAuto EducateYouTube · Mar 28, 2025
What you should do

Check the filter: Inspecting the air filter is a simple task for most vehicles and can be done during regular maintenance like oil changes.
Replace it if dirty: If the filter appears dark, clogged, or full of debris, it's time for a replacement to restore your engine's performance and efficiency.

Can I just clean my air filter instead of replacing it?

Washing the filter with a soapy water mixture helps remove stubborn dirt and extend its life. Air filters should be cleaned or replaced if there's a noticeable decrease in mileage or acceleration. Despite the ability to clean them, air filters still need to be replaced every 15,000 miles for optimal performance.

What happens if I don't change my air filter in my car?

If you don't change your car's air filter, it will get clogged, which can lead to poor engine performance, decreased fuel efficiency, and potentially expensive engine damage. A dirty air filter restricts airflow, disrupting the air-fuel ratio, which can cause symptoms like rough idling, acceleration problems, and a lit "check engine" light. For cabin air filters, this can mean poor air quality inside the car, affecting HVAC performance and potentially causing health issues for passengers with allergies or respiratory problems.

You can watch this video to learn about the signs and symptoms of a clogged air filter: 43s8020 AutomotiveYouTube · Sep 15, 2024
Engine air filter

Reduced performance: A clogged filter makes the engine work harder, leading to a loss of power, sluggish acceleration, and rough idling.
Lower fuel efficiency: The engine's air-to-fuel ratio can be disrupted, causing it to use more fuel to compensate.
"Check engine" light: The car's computer may trigger the check engine light if the air-to-fuel ratio is too far off.
Engine damage: In severe cases, a dirty filter can allow dirt and debris into the engine, causing abrasion and wear on internal components like cylinder walls and piston rings.

Cabin air filter

Poor cabin air quality: A clogged filter can't effectively clean the air that circulates in the passenger compartment, leading to unpleasant odors and low-quality air.
HVAC issues: It can cause the vehicle's heating and cooling system to work harder and less efficiently.
Health concerns: Pollutants, mold, and fumes can build up on the filter and be circulated into the cabin, which can aggravate allergies and respiratory conditions.

This video explains what happens when you don't replace the cabin air filter: 54sMercie J Auto Care, llcYouTube · Nov 1, 2023

Kevin Bennett

Company Owner

Kevin Bennet is the founder and owner of Kevin's Autos, a leading automotive service provider in Australia. With a deep commitment to customer satisfaction and years of industry expertise, Kevin uses his blog to answer the most common questions posed by his customers. From maintenance tips to troubleshooting advice, Kevin's articles are designed to empower drivers with the knowledge they need to keep their vehicles running smoothly and safely.