NGK SILZKR7A-S Iridium Spark Plug (Stock No. 7718)
This NGK Laser Iridium spark plug delivers a strong, consistent spark with long service life. It helps cold starts, smooth idle, and reliable performance under boost or high load. Ideal for standard and lightly tuned petrol engines that specify an NGK heat range 7 plug.
- Fine iridium centre electrode for clean, stable ignition
- Resistor design to reduce electrical noise that can affect the ECU
- Durable ground electrode and gasket seat for reliable sealing
| Part Category | 686 – Spark Plug |
| NGK Part Number | SILZKR7A-S |
| NGK Stock Number | 7718 |
| GTIN | 87295177181 |
| Thread Diameter | M12 x 1.25 |
| Reach (Thread Length) | 26.5 mm |
| Hex Size | 14 mm |
| Seat Type | Gasket (flat seat) |
| Heat Range | 7 (NGK scale) |
| Centre Electrode | Laser-welded iridium fine tip |
| Ground Electrode | High-nickel alloy, cut-back design |
| Resistor | Yes |
| Factory Gap | 0.8 mm (check and adjust to vehicle spec) |
| Recommended Tightening Torque | 18-25 Nm (12 mm gasket seat, aluminium head) |
Fitment Guidance
Commonly specified for various modern direct-injection petrol engines that require a 12 mm, long-reach, heat range 7 iridium plug. Use our vehicle lookup or see the Vehicle Fitment tab to confirm exact compatibility by engine code and year.
Note: Do not sand or file the iridium tip. Always fit to the manufacturer’s torque and gap specifications.
The price displayed is for a single plug, please add the desired amount to your basket.



