Table of Contents
12 September 2025 (updated) How often to change the air filter, how to do it properly and how much it costs
Replacing your engine air filter regularly is one of the simplest maintenance tasks for your vehicle but can make a big difference. A clean filter ensures optimal engine performance and fuel efficiency while extending the engine's lifespan by preventing contaminants from entering it. Yet many drivers overlook this inexpensive maintenance task. Knowing when and how to replace your engine filter can save you money and keep your car running smoothly.
Car air filter replacement – how to know when it's needed
Engine air filter replacement is recommended every 12,000–30,000 miles, but driving conditions also matter. Check the manufacturer’s recommended maintenance interval as a guideline and keep an eye out for decreased fuel efficiency, rough idling, unusual engine sounds or warning lights.
How to tell if a car air filter needs replacing
To determine whether your air filter needs to be replaced, follow these steps:
- Carry out a visual inspection. A clean filter appears white or off-white, while a dirty filter looks grey or brown with visible debris.
- Hold the filter up to a light source. If light doesn't pass through easily, it's time to replace it. Watch for performance indicators like reduced acceleration, decreased fuel efficiency (you find you need to fill up the tank more often), or rough idling.
- Listen for unusual engine sounds that might indicate your engine is struggling to get proper airflow.
- Pay attention to warning lights on your dashboard, which may signal restricted airflow affecting engine performance.
How often to replace the air filter in a car
As mentioned above, most manufacturers recommend replacing your car's engine filter every 15,000-30,000 miles, depending on your vehicle make and model. However, this is just a guideline. If you regularly drive in dusty areas or heavily polluted urban environments, you'll need to change more often, possibly every 6,000–12,000 miles. Drivers in clean environments might extend to over 30,000 miles. Always consult your owner's manual for specific engine air filter change intervals. AUTODOC experts suggest inspecting the filter at every oil change (around 5,000–7,500 miles) and replacing it when visibly dirty rather than strictly following intervals based on mileage.
-9%
K&N Filters Air filter
Length: 283 mm, Square, Long-life Filter
Article number: 33-2221
compared to
RRP
£ 51,90
£ 47,20
price incl. 20% VAT, excl. delivery costs
-46%
MANN-FILTER Air filter
Ø 133 mm, Filter Insert
Article number: C 16 134/2
compared to
RRP
£ 22,54
£ 12,07
price incl. 20% VAT, excl. delivery costs
DPA Air Filter Housing Cover
Article number: 11290662502
£ 59,31
price incl. 20% VAT, excl. delivery costs
-12%
Article number: 33-2940
compared to
RRP
£ 138,42
£ 120,83
price incl. 20% VAT, excl. delivery costs
-11%
K&N Filters Air filter
Length: 356 mm, Square, Long-life Filter
Article number: 33-3028
compared to
RRP
£ 86,52
£ 76,28
price incl. 20% VAT, excl. delivery costs
Air filter change interval in kilometres
In kilometres, the manufacturer recommended intervals for changing the engine filter are between 20,000 and 50,000 km.
How to change the air filter
All you need to do this yourself is a new air filter, basic tools, and a few minutes of your time.
- Locate the air filter housing in your engine compartment. Consult your owner's manual if needed.
- Unfasten the clips, screws, wing nuts, or clamps securing the air filter housing.
- Open the housing carefully and note how the old filter is positioned before removing it.
- Remove the old filter.
- Clean any dust or debris from the inside of the housing using a damp cloth.
- Insert the new filter with the rubber seal facing in the same direction as the old one.
- Close the housing, ensuring proper alignment, and secure all fasteners.
- Double-check that everything is properly seated and tightened.
This simple maintenance task typically takes less than 15 minutes and requires no special tools.
Air filter replacement cost
A new air filter costs typically range from £8–£20 for most standard vehicles, while premium or specialised filters for luxury or performance cars may cost £25–£40. Garages and dealerships generally charge an additional £15–£30 for labour but you can save this with DIY replacement.
-22%
FAST Air Filter Housing Cover
Article number: FT37701
compared to
RRP
£ 91,15
£ 70,42
price incl. 20% VAT, excl. delivery costs
Article number: PP1683
£ 28,92
price incl. 20% VAT, excl. delivery costs
BOSCH Air filter
Length: 505 mm, Filter Insert
Article number: F 026 400 365
£ 36,77
price incl. 20% VAT, excl. delivery costs
-19%
FEBI BILSTEIN Air filter
Length: 260 mm, Filter Insert
Article number: 49658
compared to
RRP
£ 20,99
£ 16,96
price incl. 20% VAT, excl. delivery costs
-47%
MANN-FILTER Air filter
Length: 367 mm, Filter Insert
Article number: C 37 009
compared to
RRP
£ 76,30
£ 40,29
price incl. 20% VAT, excl. delivery costs
What happens if you don't replace the air filter in a car
Not replacing your car's engine air filter can cause a series of increasingly serious problems that affect fuel efficiency, vehicle performance, and engine longevity. What begins as a minor maintenance oversight can develop into costly repairs if neglected for too long. Consequences include:
- decreased fuel efficiency as your engine uses more fuel to compensate for reduced airflow, directly impacting your wallet
- reduced power and sluggish acceleration from improper air-fuel mixture
- rough idling and unusual engine sounds during operation
- check engine light activation when sensors detect combustion problems
- spark plug fouling causing misfires and worsening performance
- premature engine wear as contaminants bypass the clogged filter
- engine strain potentially leading to overheating
- damage to cylinders, pistons, and valves from abrasive particles
- potential for severe engine damage requiring costly repairs or replacement
This simple, inexpensive maintenance job protects both your engine and your finances.
A useful video on this topic:
How Often Should You Change Your Air Filter?
Top products related to this topic:
