NGK PMR8B Spark Plug – Stock No. 6378
The NGK PMR8B is a high-quality resistor spark plug built for clean ignition and long service life. It uses a fine-wire precious metal centre electrode for a strong, reliable spark under load. The projected tip helps improve cold starts and throttle response, especially on tuned or high-compression engines. It is a direct replacement where PMR8B is specified and can offer smoother idle and more consistent performance compared to generic plugs.
- Strong spark and stable combustion thanks to fine-wire centre electrode
- Projected tip aids cold starts and reduces fouling
- Resistor design cuts electrical noise that can affect the ECU
- Built to NGK’s OE standards for durability and heat control
| Part Number | PMR8B |
|---|---|
| NGK Stock Number | 6378 |
| GTIN | 087295163788 |
| Category | 686 – Spark Plug |
| Heat Range (NGK) | 8 |
| Resistor | Yes |
| Thread Diameter | 10 mm |
| Thread Pitch | 1.0 |
| Reach (Thread Length) | 19 mm |
| Hex Size | 14 mm |
| Seat Type | Gasket |
| Electrode Configuration | Fine-wire centre, projected tip |
| Centre Electrode Material | Precious metal (platinum-type) |
| Ground Electrode | Nickel alloy |
| Spark Gap (preset) | 0.7 – 0.8 mm |
| Terminal Type | Solid (non-removable) |
Important: Only use this plug where PMR8B is specified by the manufacturer. Always match heat range, thread, reach, and seat type to your engine.
Compatibility guidance
Fits selected engines that use a 10 mm, long-reach, gasket-seat, projected-tip resistor plug with NGK heat range 8. Use our vehicle lookup or check the Vehicle Fitment tab to confirm it suits your specific model.
The price displayed is for a single plug, please add the desired amount to your basket.


