Mazda 2 Spark Plugs: Intervals, Fitment & Warning Signs
On the Mazda 2, repeatedly removing coil boots to "just check" plugs genuinely risks a microscopic scratch modern ignition systems can't tolerate.
Illustration for editorial purposes
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OEM Part Number: confirm via engine code — aftermarket NGK 4912 / Bosch 0 242 135 529
| Petrol engines in this generation | 1.5 (DJ2HA) 107 HP, 1.5 (DJLFS) 111 HP, 1.5 75 HP, plus SKYACTIV-G and SKYACTIV-G M Hybrid variants; diesel 1.5 D (DJ5FS) 105 HP also listed |
|---|---|
| Spark plugs (aftermarket) | NGK 4912 (iridium, M12x1.25, 14 mm hex); NGK 94124 (iridium, M12x1.25, 14 mm hex); NGK 1654 (iridium, M12x1.25, 14 mm hex); NGK 6283 (iridium, M12x1.25, 14 mm hex); Denso IXEH22TT (iridium centre, platinum earth, M12x1.25); Denso ZC20HPR11 (iridium centre, platinum earth, M12x1.25; OE P51R-18-110); Champion OE253 (iridium, 1.0 mm gap, M12x1.25, 14 mm hex) |
| Genuine (OE) numbers quoted | Denso ZC20HPR11 = P51R-18-110; Denso K16PR-U11 = 18814-11051; Kamoka 7100053 = 9091901253 |
| Fitment notes | The SKYACTIV-G engine takes a 14 mm hex M12x1.25 iridium plug with a 1.0 to 1.1 mm gap, and the Mazda OE reference is P51R-18-110; the plugs are not tied to individual engine codes. Brisk 1708 quotes a 100,000 km interval. |
A Genuinely Important, Counter-Intuitive Warning Worth Knowing — Mazda 2 Spark Plugs
This is genuinely worth knowing before repeatedly pulling plugs to "just check" them: every time a coil and boot is removed and reinstalled, there's a genuine risk of causing a microscopic scratch on the plug's porcelain insulator. On modern engines, this risk is considerably higher than on older cars — leaner fuel mixtures and wider plug gaps mean today's ignition systems require far higher voltage, meaning a tiny scratch that would once have gone unnoticed can now genuinely cause a misfire.
It's also worth knowing a genuinely useful diagnostic distinction: finding oil specifically on the threads of a newly fitted spark plug points toward a valve cover gasket or seal leak, rather than a fault with the plug or coil itself.
Mazda 2 Spark Plugs: A Cheap Part That Causes Expensive-Feeling Problems
On the Mazda 2, spark plug wear tends to creep in quietly — idle gets a little rougher, throttle response softens slightly — the kind of symptoms that get blamed on almost anything else under the bonnet. Given how cheap the part itself is, it's an easy one to put off for longer than makes sense.
Mazda 2 Spark Plugs: Watch: Replacing It
Generation not stated in title (1.5 petrol), so it may be a DE-gen car. Alternatives: 9AvLj9hOorI, jkTPhI8xxtc.
Mazda 2 Spark Plugs: What They Do
Inside each cylinder of the Mazda 2, spark plugs ignite the compressed fuel-air mixture, and their condition has a direct effect on combustion efficiency, fuel economy and how smoothly the engine runs. Petrol engines can't function without them; diesels don't use spark plugs, relying on compression alone to ignite fuel.
Mazda 2 Spark Plugs: Generations & Spark Plug Count
| Diesel variants, where fitted | Not applicable — diesel engines use compression ignition and have no spark plugs at all |
|---|---|
| Petrol variants (all trims) | 4 spark plugs — one per cylinder |
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Mazda 2 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 Mazda Spark Plugs
The same part, covered across other Mazda models.