NGK BP6EF Spark Plug – Stock No. 4666
The NGK BP6EF is a reliable, projected-tip spark plug for petrol engines that use a 14 mm long-reach plug. It offers clean ignition, steady idle, and dependable cold starts. The NGK 6 heat range suits everyday road use and mild performance tuning in many engines that specify this type.
Always set the gap and torque to your engine maker’s spec. Check that a non-resistor plug is suitable for your ignition and electronics.
- Projected tip helps efficient combustion and throttle response
- Non-resistor design for strong spark where specified
- Durable nickel alloy electrodes with copper core for good heat transfer
| Manufacturer | NGK |
| Part Number | BP6EF |
| NGK Stock Number | 4666 |
| GTIN | 087295146668 |
| Category | 686 – Spark Plug |
| Thread Diameter | 14 mm |
| Thread Reach | 19 mm (3/4 in) |
| Seat Type | Flat seat with gasket |
| Hex Size | 16 mm (5/8 in) |
| Heat Range | NGK 6 |
| Resistor | No |
| Insulator Projection | Projected tip (P) |
| Centre Electrode | Nickel alloy with copper core |
| Ground Electrode | Single electrode |
| Factory Gap | 0.8 mm (adjust as required) |
| Terminal Type | Solid SAE |
Fitment guidance
Suitable for petrol engines that specify a 14 mm thread, 19 mm reach, gasket seat, projected tip, and non-resistor plug in NGK heat range 6. Use our vehicle lookup to confirm fitment or check the Vehicle Fitment tab for full details.
Installation notes
– Gap to the vehicle specification.
– Apply a new gasket and tighten to the correct torque.
– Inspect and replace at the service interval for your engine.
The price displayed is for a single plug, please add the desired amount to your basket.


