Mercedes-Benz CLA Spark Plugs: Intervals, Fitment & Warning Signs
On the CLA, swapping coil packs to isolate a misfire, a technique that works reliably on most cars, has genuinely confused even experienced mechanics on related models.
Illustration for editorial purposes
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OEM Part Number: confirm via engine code — aftermarket NGK 95875 / Bosch 0 241 140 537
| Petrol engines in this generation | CLA 180 (117.342) and other 117-series petrol variants; diesel CLA 220 CDI (117.303) also listed |
|---|---|
| Spark plugs (aftermarket) | NGK 95875 (iridium, M12x1.25, 14 mm hex); NGK 90654 (iridium, M12x1.25, 14 mm hex); NGK 97566 (iridium, M12x1.25, 14 mm hex); NGK 90912 (iridium, 0.7 mm gap, M12x1.25, 14 mm hex, 27 mm reach, taper seat); Champion OE269 (iridium, 0.7 mm gap, M12x1.25, 14 mm hex); Bosch 0 241 140 537 (0.7 mm gap, M12x1.25, 14 mm hex); Beru Z502 (iridium centre, platinum earth, 0.7 mm gap, M12x1.25, 14 mm hex) |
| Genuine (OE) numbers quoted | Vemo V99-75-0083 = A 270 159 06 00; Renault 224019185R quoted as an OE part |
| Fitment notes | The petrol engines take an M12x1.25 / 14 mm hex iridium plug with a 0.7 mm gap, in either a flat-seat (26.5 mm) or taper-seat (27 mm, NGK 90912) version, so check the seat type for the engine; the plugs are not tied to individual engine codes. Brisk 1989 quotes a 100,000 km interval. |
Mercedes-Benz CLA Spark Plugs: A Cheap Part That Causes Expensive-Feeling Problems
A worn set of spark plugs in the Mercedes-Benz CLA doesn't make itself obvious: idle roughens slightly, acceleration loses a bit of urgency, and both symptoms are easy to blame on something else entirely. Given how inexpensive the part is, it often gets neglected for far longer than it should.
Mercedes-Benz CLA Spark Plugs: What They Do
Every combustion cycle in the Mercedes-Benz CLA's petrol engine starts with a spark plug igniting the compressed fuel-air mixture, and their condition shapes efficiency, economy and smoothness directly. Diesel versions don't need them at all, relying purely on compression to ignite fuel.
Mercedes-Benz CLA Spark Plugs: Generations & Spark Plug Count
| Diesel variants | Not applicable — diesel engines use compression ignition and have no spark plugs at all |
|---|---|
| Petrol variants (all standard trims) | 4 spark plugs — one per cylinder |
| AMG 35/45 performance trims, where fitted | Also 4 spark plugs — these use a more highly-tuned version of the same four-cylinder engine family rather than a different cylinder count |
Mercedes-Benz CLA Spark Plugs: Watch: Replacing It
C117 generation.
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A Genuinely Distinctive, Useful Finding Worth Knowing — Mercedes-Benz CLA Spark Plugs
If you're trying to isolate which cylinder is genuinely misfiring by swapping coil packs between cylinders, this is genuinely worth knowing: this standard diagnostic technique, which works reliably on most cars, has genuinely confused even experienced mechanics on related models, since the fault code can sometimes stay locked to the original cylinder position rather than following the coil to its new location.
It's also genuinely worth knowing a useful preventative tip: applying a small amount of dielectric grease between the top of the spark plug and the coil boot during any plug or coil replacement is a simple step worth taking.
Mercedes-Benz CLA Spark Plugs: Warning Signs, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Spark Plugs Guide for symptoms of worn plugs, why matching your exact plug specification matters, and trusted brands to buy from.
More Mercedes-Benz Spark Plugs
The same part, covered across other Mercedes-Benz models.