NGK DILFR6N-T Laser Iridium Spark Plug – Stock No. 91657
The NGK DILFR6N-T is a premium Laser Iridium spark plug designed for clean ignition, stable idle, and long service life. It delivers a strong, consistent spark that helps the engine start easily, burn fuel efficiently, and run smoothly over time.
Iridium handles heat well and resists wear, so the gap stays stable for longer. This keeps performance consistent and can help maintain fuel economy when the rest of the engine is in good condition.
Use this plug as a like-for-like replacement where DILFR6N-T (91657) is specified by the vehicle maker or NGK. If you are unsure, use the site’s vehicle lookup or check the Vehicle Fitment tab.
| Specification | Value |
|---|---|
| Part number | DILFR6N-T |
| NGK stock number | 91657 |
| Category | 686 – Spark Plug |
| GTIN | 087295916575 |
| Thread diameter | 12 mm |
| Seat type | Tapered seat |
| Hex size | 14 mm |
| Heat range | 6 (NGK scale) |
| Resistor | Yes |
| Centre electrode | Laser-welded iridium |
| Ground electrode | Platinum pad |
| Gap | Factory set – do not adjust unless specified by NGK/OE |
- Reliable cold starts and smooth idle thanks to a fine iridium tip.
- Stable spark under load for consistent performance.
- Long service life – reduced wear keeps the gap stable.
- Resistor design helps reduce electrical noise that can affect the ECU.
Important: Only use if your engine specifically calls for NGK DILFR6N-T (91657). Fitment varies by engine family. Many modern petrol engines that use 12 mm tapered-seat iridium plugs may specify this part. Always confirm with the vehicle lookup or the Vehicle Fitment tab before ordering.
The price displayed is for a single plug, please add the desired amount to your basket.


