NGK Iridium IX Spark Plug – BPR6EIX-11 (Stock No. 3903)
This Iridium IX plug is built for reliable ignition and long service life. The fine-wire iridium centre needs less voltage to fire, which helps cold starts, smooth idle, and clean combustion. It is a direct replacement where a 14 mm thread, 19 mm reach, projected tip and NGK heat range 6 are specified.
- Fine-wire iridium tip for strong spark under load
- Resistor design to reduce electrical noise
- Projected insulator for efficient flame kernel
- Factory-set 1.1 mm gap for stable ignition
| Part Category | 686 – Spark Plug |
| Part Number | BPR6EIX-11 |
| NGK Stock Number | 3903 |
| GTIN | 087295139035 |
| Thread Diameter | 14 mm |
| Thread Pitch | 1.25 |
| Reach (thread length) | 19 mm |
| Hex Size | 21 mm (13/16 in) |
| Seat Type | Flat seat with crush gasket |
| Heat Range | 6 (NGK) |
| Resistor | Yes |
| Centre Electrode | Iridium, approx. 0.6 mm fine wire |
| Ground Electrode | Nickel alloy, tapered cut |
| Tip Style | Projected insulator |
| Factory Gap | 1.1 mm |
Fitment guidance
Suitable for many petrol engines that require a 14 mm x 1.25 thread, 19 mm reach, projected tip, resistor plug, heat range 6, and a 1.1 mm gap. Use our vehicle lookup to confirm fitment or see the Vehicle Fitment tab for full details.
Important: Always check and set the gap to the vehicle manufacturer’s spec, and tighten to the correct torque.
The price displayed is for a single plug, please add the desired amount to your basket.


