NGK IFR6L11 Laser Iridium Spark Plug – Stock No. 3678
The NGK IFR6L11 is a Laser Iridium spark plug designed for long life and consistent performance. It uses a fine iridium centre electrode for a strong spark and a platinum pad on the ground electrode to reduce wear. This helps cold starts, smooth idle, and cleaner combustion, with stable performance over a long service interval.
Suitable as a high-quality replacement for engines that specify NGK heat range 6 and a 1.1 mm gap. Always confirm fitment with the vehicle lookup or the Vehicle Fitment tab.
- Strong, reliable spark for better throttle response and smooth running
- Long service life thanks to iridium centre and platinum ground pad
- Resistor design reduces electrical noise that can affect electronics
Key Specifications
| Part number | IFR6L11 |
| NGK stock number | 3678 |
| GTIN | 087295136782 |
| Series | Laser Iridium |
| Spark plug type | Resistor |
| Heat range | 6 (NGK) |
| Thread diameter | 14 mm |
| Thread reach | 19 mm |
| Hex size | 16 mm |
| Seat type | Flat seat with gasket |
| Gap | 1.1 mm preset |
| Centre electrode | Fine iridium tip (approx. 0.6 mm) |
| Ground electrode | Nickel with laser-welded platinum pad |
| Projection | Projected insulator type |
| Terminal | Solid terminal |
Installation Notes
– Fit to a cold engine. Check thread reach and seat type match your cylinder head.
– For new gasket plugs, tighten 1/2 to 2/3 turn after finger tight. For used plugs, tighten 1/12 turn.
– Avoid forcing the gap on iridium plugs. If adjustment is required, do so carefully at the ground strap only.
– Use the vehicle lookup to confirm this exact part for your engine.
The price displayed is for a single plug, please add the desired amount to your basket.


