NGK PMR9B Spark Plug (Stock No. 4717)
The NGK PMR9B is a high-quality resistor spark plug designed for reliable ignition under hard use. It delivers a clean, consistent spark to help cold starts, smooth idle, and stable performance at high RPM. A colder NGK heat range 9 helps manage combustion temperatures in demanding conditions, reducing the risk of knock and pre-ignition.
Use it as a direct-service replacement or as part of a maintenance refresh on performance-focused engines. If your engine is tuned or regularly driven hard, a colder plug like this can offer extra thermal headroom and more consistent performance.
- Strong, consistent spark for smoother idle and better throttle response
- Colder heat range for improved knock resistance under load
- Resistor design to reduce electrical noise that can affect sensors and ECU
Fitment Guidance
This plug is used in specific high-performance applications. Please use the site’s vehicle lookup to confirm fitment, or check the Vehicle Fitment tab for full details before ordering.
| Specification | Value |
|---|---|
| Part Number | PMR9B |
| NGK Stock Number | 4717 |
| Category | 686 – Spark Plug |
| GTIN | 087295147177 |
| Spark Plug Type | Resistor |
| Heat Range (NGK) | 9 |
| Configuration | Single ground electrode |
| Seat/Thread | Refer to Vehicle Fitment tab for exact sizing |
| Gap | Pre-set by NGK – check and adjust only if specified by your service manual |
Tip: Always compare the removed plug’s size and reach, and follow the torque spec in your service manual. Over-tightening can damage threads; under-tightening can cause poor heat transfer.
The price displayed is for a single plug, please add the desired amount to your basket.


