The Audi A4 B8 (2009–2016) air filter is one of the simplest maintenance items you can tackle yourself. US Audi dealers charge $60–$80 for this job. You can do it in 10 minutes with your bare hands and a $20 filter from Amazon.
Audi A4 B8 Air Filter Specs (US Models)
US-market Audi A4 B8s were sold with two main engines:
- 2.0T TFSI (four-cylinder) — the most common in the US
- 3.2 FSI V6 — less common but same procedure
For the 2.0T, the correct filter is approximately 279 x 234 x 47mm. OEM part number: 8K0 133 843. Aftermarket equivalents by Mann, Mahle, or Bosch work well and are all available on Amazon USA.
Replacement Steps
1. Open the Hood
The hood release is under the dash on the left side. Pop the secondary latch at the front of the hood.
2. Locate the Airbox
On the 2.0T, the airbox is on the driver's side of the engine bay (left side when standing in front of the car). It's a rectangular black plastic box connected to the intake tube.
3. Release the Airbox Clips
Four plastic clips hold the top of the airbox to the bottom. Flip them up or pry them with your fingers or a flat-head screwdriver. Lift the lid.
4. Remove the Old Filter
Pull the old filter straight out. Note the direction of airflow (arrow marked on the filter frame — arrow should point toward the engine).
5. Clean the Airbox
Wipe any debris from the bottom of the airbox with a shop rag. Do not use compressed air inside the airbox with the intake pipe connected — you'll push debris into the engine.
6. Install the New Filter
Drop in the new filter with the rubber seal facing up, matching the old one's orientation. Press it firmly into the housing.
7. Close and Clip
Reattach the lid and flip all four clips back down.
How Often to Replace
Audi recommends every 25,000–30,000 miles in normal US driving conditions. If you drive on unpaved roads, dusty highways in the Southwest, or in areas with high pollen, change it every 15,000 miles.
A clogged air filter costs you fuel economy and performance. The 2.0T TFSI is sensitive to airflow restrictions — clean air equals optimal boost pressure.
Cost Comparison
| Method | Cost | Time | |--------|------|------| | US Audi Dealer | $65–85 | 1 hour appointment | | Independent Shop | $40–55 | Same-day drop-off | | DIY with Amazon part | $15–22 | 10 minutes |
This is the easiest maintenance item on the entire car. There is no reason to pay someone else to do it.