NGK LZFR6AI Spark Plug – Stock No. 3656
The NGK LZFR6AI is a high-quality resistor spark plug with an iridium centre electrode. It delivers a strong, stable spark for clean combustion and smooth running. Iridium helps the plug last longer and resist wear, so performance stays consistent over time.
This plug is a good choice for stock and lightly tuned engines seeking reliable ignition, easy starting, and steady idle. It is built to OEM standards for dependable fit and function.
- Smoother idle and better throttle response under load
- Long service life thanks to hard-wearing iridium tip
- Strong cold starting and stable spark at high RPM
Fitment note: Vehicle compatibility varies. Please use our vehicle lookup or check the Vehicle Fitment tab to confirm.
Technical Specifications
| Part Number | LZFR6AI |
| NGK Stock Number | 3656 |
| Part Category | 686 – Spark Plug |
| GTIN | 087295136560 |
| Plug Type | Resistor |
| Heat Range (NGK) | 6 |
| Centre Electrode | Iridium |
| Ground Electrode | Nickel alloy |
| Gap | Factory set – do not adjust unless specified by the vehicle manufacturer |
Installation tips: Fit only to a cold engine. Check the old plug for signs of engine issues before refitting. Always use the correct torque and follow the vehicle manufacturer’s service procedure.
The price displayed is for a single plug, please add the desired amount to your basket.


