NGK BPR5EP-11 Spark Plug – Stock No. 3971
This NGK spark plug delivers a clean, consistent spark for reliable starts and smooth running. The projected tip improves ignitability, while the built-in resistor helps protect modern electronics. A platinum centre electrode resists wear and keeps the gap stable for longer service life.
Why it matters
- Stable spark for better cold starts and smoother idle
- Platinum centre tip reduces wear and helps maintain performance over time
- Resistor design cuts radio noise and ECU interference
Always match plug specifications to your engine. Use the vehicle lookup or check the Vehicle Fitment tab.
Technical specifications
| Part number | BPR5EP-11 |
| NGK stock number | 3971 |
| Category | 686 – Spark Plug |
| GTIN | 087295139714 |
| Thread diameter | 14 mm |
| Thread reach | 19 mm |
| Hex size | 20.8 mm (13/16 inch) |
| Seat type | Gasket |
| Heat range | 5 (NGK scale) |
| Resistor | Yes |
| Insulator projection | Projected tip |
| Centre electrode | Platinum |
| Ground electrode | Nickel alloy |
| Factory gap | 1.1 mm |
| Terminal type | Removable terminal nut (SAE) |
| Recommended tightening angle (new gasket) | 1/2 to 2/3 turn after finger-tight |
| Typical torque (14 mm gasket seat) | 25-30 Nm (follow vehicle spec) |
| Thread plating | Trivalent plating (no anti-seize required) |
Fitment guidance
Suited to petrol engines that specify a 14 mm thread, 19 mm reach, projected tip, resistor plug with 1.1 mm gap and NGK heat range 5. Use the site’s vehicle lookup to confirm fitment, or check the Vehicle Fitment tab for full details.
The price displayed is for a single plug, please add the desired amount to your basket.


