Spark plugs Mercedes-Benz C-Class W205 M274 (2.0) — NGK, Bosch, Denso
Spark plugs for Mercedes-Benz C-Class W205 M274 (2.0L, 2014–2021) — OEM-spec NGK, Bosch, Denso and Champion part numbers with replacement interval.
Engine Specifications
| Parameter | Value |
|---|---|
| Make / Model | Mercedes-Benz C-Class W205 |
| Engine Code | M274 |
| Displacement / Fuel | 2.0L petrol |
| Production Years | 2014–2021 |
| Plug type | iridium |
| Thread | M14x1.25 |
| Reach | 19 mm |
| Hex size | 16 mm |
| Electrode gap | 0.8 mm |
| Heat range | 7 |
Compatible Spark Plugs
| Brand | Part Number | Type |
|---|---|---|
| NGK | LZKER7B8EG | OE supplier |
| Bosch | 0 242 236 631 | OE supplier |
| Denso | IW22 | OE supplier |
| Champion | 9801 | aftermarket |
Replacement Interval
| Parameter | Value |
|---|---|
| Mileage | 60 000 km |
| Time | 4 years |
Iridium and platinum plugs last 2–3× longer than standard copper plugs. Replace them on schedule — worn plugs increase fuel consumption by 3–5% and reduce power output.
Choosing Spark Plugs for M274
- Use the correct plug type — the M274 requires iridium plugs. Upgrading from standard to iridium is acceptable.
- Check the electrode gap — verify the gap is 0.8 mm before installation.
- Torque correctly — for M14x1.25 thread: aluminium head 20–25 Nm, cast iron head 25–30 Nm.
- Replace as a full set — always replace all cylinders at once to ensure even combustion across all cylinders.
FAQ
Which spark plugs fit Mercedes-Benz C-Class W205 M274?
NGK LZKER7B8EG, Bosch 0 242 236 631, Denso IW22. All three are OE suppliers and guarantee compatibility with this engine.
How often should spark plugs be replaced on Mercedes-Benz C-Class W205?
Every 60 000 km or 4 years, whichever comes first. Iridium plugs (LZKER7B8EG) have a longer service life compared to standard nickel plugs.
Can I fit a different type of spark plug in the M274?
Upgrading to iridium or platinum is acceptable and gives a slight improvement in cold starts. Do not change the heat range (7) — an incorrect heat range can cause pre-ignition or fouling.
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