Spark plugs SEAT Leon III CJSB (1.8) — NGK, Bosch, Denso
Spark plugs for SEAT Leon III CJSB (1.8L, 2012–2020) — OEM-spec NGK, Bosch, Denso and Champion part numbers with replacement interval.
Engine Specifications
| Parameter | Value |
|---|---|
| Make / Model | SEAT Leon III |
| Engine Code | CJSB |
| Displacement / Fuel | 1.8L petrol |
| Production Years | 2012–2020 |
| Plug type | iridium |
| Thread | M14x1.25 |
| Reach | 19 mm |
| Hex size | 16 mm |
| Electrode gap | 0.7 mm |
| Heat range | 7 |
Compatible Spark Plugs
| Brand | Part Number | Type |
|---|---|---|
| NGK | ILZKAR7B8EG | OE supplier |
| Bosch | 0 242 229 921 | OE supplier |
| Denso | IW20 | OE supplier |
| Champion | 9700 | 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 CJSB
- Use the correct plug type — the CJSB requires iridium plugs. Upgrading from standard to iridium is acceptable.
- Check the electrode gap — verify the gap is 0.7 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 SEAT Leon III CJSB?
NGK ILZKAR7B8EG, Bosch 0 242 229 921, Denso IW20. All three are OE suppliers and guarantee compatibility with this engine.
How often should spark plugs be replaced on SEAT Leon III?
Every 60 000 km or 4 years, whichever comes first. Iridium plugs (ILZKAR7B8EG) have a longer service life compared to standard nickel plugs.
Can I fit a different type of spark plug in the CJSB?
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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