BenzUnited Parts
M278 Mercedes Intake Spacer Kit + Set of K&N Drop-in Performance Air Filters (4.7L V8 Bi-Turbo)
M278 Mercedes Intake Spacer Kit + Set of K&N Drop-in Performance Air Filters (4.7L V8 Bi-Turbo)
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The ultimate OEM+ intake upgrade — K&N high-flow filters + precision airbox spacers for maximum throttle sharpness and mid-range power.
Why This K&N + Spacer Combo Crushes It on the M278
Raises the filter sealing plane for smoother, higher-volume airflow into the MAF housing.
Legendary oiled cotton media + Million Mile Warranty® — proven HP gains, washable, CARB legal, no tuning needed.
Keeps perfect cold-air routing & heat shields — zero heat-soak, zero MAF issues.
Real-World Results Owners Report
- Crispier throttle tip-in and noticeably stronger mid-range pull
- Better power consistency on hot days and repeated pulls
- Perfect headroom for headers, downpipes, tune, or E85
- Zero check-engine lights • Fully reversible • No ECU retune
“K&N filters + spacers on my E550 with downpipes = night and day difference. Throttle is razor sharp and it pulls way harder now.” – Alex R., 2015 CLS550 • 512 whp
What You Get (Full Combo Kit)
- ✔ 2 × Precision CNC-machined airbox spacers (left + right)
- ✔ 2 × K&N 33-2474 High-Flow Performance Air Filters (pre-oiled)
Fits These M278 4.7L BiTurbo V8 Models
| Model | Chassis | Years |
|---|---|---|
| E 550 • CLS 550 | W212 / C218 | 2012–2016 |
| S 550 / S 560 • CL 550 | W221 • W222 • C216 • C217 • A217 | 2011–2017 |
| SL 550 | R231 | 2013–2020 |
| GL / GLS 450 • 550 • ML / GLE 550 | X166 • W166 | 2012–2019 |
✅ Always verify M278 engine code • Message me if unsure
Frequently Asked Questions
Do I need a tune after installing this?
No. This kit runs on the stock tune with no ECU changes, no check engine lights, and no MAF issues — the factory airbox and cold-air routing are retained.
What do the spacers actually do?
They raise the filter sealing plane, which lets more air move into the MAF housing than the factory arrangement allows. You keep the OEM airbox and heat shielding, so there's no heat soak — unlike an open-element intake.
How long does the install take?
About 20 minutes with a 10mm socket. No other tools needed, and it's fully reversible if you ever want to go back to stock.
Do the filters need cleaning?
Yes — the K&N 33-2474 filters are washable oiled cotton, so they're cleaned and re-oiled rather than replaced. They carry K&N's Million Mile Warranty.
Is this worth it if my car is already modified?
That's where it does the most. On cars with downpipes, headers, a tune, or E85, the extra intake headroom matters more. It's a supporting mod, not a standalone power adder.
How do I confirm it fits my car?
Confirm your car has the M278 4.7L biturbo V8 — the engine code decides fitment, not the badge. Covered chassis are listed in the table above. If you're unsure, message us your year, model, and VIN and we'll confirm before you order.
Install in ~20 minutes • No tools beyond a 10mm socket • Fully reversible
BenzUnited Parts • Mercedes Performance Specialist • Ships from USA
