BenzUnited Parts
K&N 33-2181 High-Flow Air Filter – Mercedes-AMG M113 5.4L V8 | C55 AMG, CLK55 AMG, SLK55 AMG (Single Filter)
K&N 33-2181 High-Flow Air Filter – Mercedes-AMG M113 5.4L V8 | C55 AMG, CLK55 AMG, SLK55 AMG (Single Filter)
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The K&N 33-2181 is a high-flow, washable panel air filter for the Mercedes-AMG M113 5.4L V8 — CLK55 AMG, C55 AMG and SLK55 AMG. This listing includes one filter, because these cars use a single filter housing. Oiled cotton gauze media, made in the United States, drops straight into the factory housing in about ten minutes with no tuning and no modification.
What You Get
| Part Number | K&N 33-2181 |
| Quantity Included | 1 filter — one complete vehicle set |
| Filter Media | Oiled cotton gauze, pre-oiled |
| Tune Required | No |
| Install | Drop-in, 5–10 minutes, Torx driver required |
| Reusable | Yes — washable and re-oilable |
| Made In | United States |
| Ships | Within 2 business days |
Cold Air Intakes Aren't Pulling Cold Air
Ironically, "cold air intakes" use open cone filters, exposing them to hot air from the engine bay. Hot air is less dense, so the engine makes less power, and rising IATs push the ECU toward pulling timing. Worst on a hot day when you are actually driving hard.
The factory Mercedes airbox already channels cold air from the outside. Sealed, ducted to the grille. The paper panel inside is the only real restriction, and that is what this performance air filter replaces.
Fitment — M113 5.4L V8
| Model | Chassis | Years |
|---|---|---|
| C55 AMG | W203 | 2005–2006 |
| CLK55 AMG | C209 / A209 | 2003–2006 |
| SLK55 AMG | R171 | 2005–2011 |
Install & Maintenance
Undo the Torx screws on the airbox lid, lift the lid, swap the filter, and put it all back together. No cutting, no wiring, no tuning.
Wash with a cotton-gauze filter cleaner, rinsing from the clean side outward. Air dry at room temperature — no compressed air or heat — then re-oil lightly. Over-oiling is what contaminates a MAF sensor.
Warranty, Shipping & Returns
- Warranty: K&N "No-Hassle" Lifetime Limited Warranty against defects in materials and workmanship.
- Shipping: Ships within 2 business days.
- Returns: 30-day returns on unused items in original packaging.
Questions
How many filters does my car need?
One. These models use a single filter housing, and that is exactly what this listing includes.
Do I need a tune to run this?
No. This is a direct replacement for the factory panel and works on a completely stock car. A tune is where the real power is, but it is not a requirement for fitting this.
Will the filter oil damage my MAF sensor?
Not when the filter is oiled correctly. It ships pre-oiled at the right level and needs nothing before install. MAF problems come from over-oiling after a cleaning — apply lightly, let it wick in, and do not saturate. If you would rather avoid oil entirely, a dry synthetic filter is the alternative.
Is a cold air intake better than this?
On the M113, no. The factory box is already sealed and ducted to outside air, so the paper panel is the restriction rather than the box. An open cone gains a little peak flow and gives up intake temperature, which is the wrong trade. A full intake kit earns its place once you are chasing airflow beyond what the factory box supports.
How often does it need cleaning?
K&N publishes a service interval of 50,000 miles under normal street driving. Clean it sooner if it is visibly loaded — dusty roads and construction traffic shorten that considerably.
Does this fit the factory airbox without modification?
Yes. It is an OEM-shape panel filter. Nothing is cut, drilled, relocated or removed, and the factory heat shielding stays exactly as it is.
