NGK IFR6S Laser Iridium Spark Plug (99404)
Original price was: £24.14.£15.53Current price is: £15.53.
NGK IFR6S Laser Iridium Spark Plug – Stock No. 99404
NGK IFR6S is a Laser Iridium spark plug designed for stable ignition, long life, and clean running. It uses a fine iridium centre tip for a strong spark with less voltage, and a platinum pad on the ground electrode to slow wear. This helps cold starts, throttle response, and consistency under load.
Built-in resistor reduces electrical noise that can affect the radio or ECU. The solid terminal cap gives a secure connection in OE-style plug leads.
Use the site’s vehicle lookup to confirm fitment, or check the Vehicle Fitment tab for full details.
- Strong, consistent spark for smoother idle and reliable starts
- Long service life compared with standard nickel plugs
- Stable combustion under boost or high load
- Factory-set gap for quick installation
| Part number | IFR6S |
| NGK stock number | 99404 |
| Type | Laser Iridium (iridium fine-wire centre, platinum ground pad) |
| Heat range | 6 (NGK scale – medium heat rating) |
| Resistor | Yes |
| Terminal | Solid terminal (non-removable cap) |
| Gap | Preset from factory – adjust only if the vehicle manufacturer specifies |
| Service life | Extended vs. standard copper/nickel plugs (actual interval depends on engine and use) |
| Installation | Fit to clean threads and torque to the vehicle manufacturer’s spec |
Note: Always match heat range, reach, thread size, and gap to your engine. Use the vehicle lookup or the Vehicle Fitment tab to confirm this exact part.
The price displayed is for a single plug, please add the desired amount to your basket.
| Weight | 0.05 kg |
|---|---|
| Dimensions | 10 × 3 × 3 cm |
| Brand |
NGK-99404 Confirmed Fitment
Please note, this information is a combination of supplier provided compatibility data and our workshop expertise. While every effort has been made to ensure the accuracy of this information Progressive Parts Ltd are not liable for abnormalities or inaccurate data. Customers are wholly responsible for checking fitment for their vehicle. More information is available from our Terms & Conditions
UK Shipping
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DELIVERY INFORMATION
International Shipping
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DELIVERY INFORMATION
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Stock at Progressive Parts
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1+ IN STOCK in green stock is readily available in one of our warehouses for express delivery (at the time of viewing).
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0 IN STOCK in orange means everybody we work with is unfortunately out of stock. Stock is not available in the UK. The best course of action is to place an order to create an allocation from the next batch arriving.
OUT OF STOCK in red. This product is unavailable to order, for whatever reason we're unable to obtain stock or there is an issue with supply/lead times.
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Type-approval then, is a certain guarantee that an end user will receive a product of OE equivalent performance attributes.
Products on the Progressive Parts website that meet this approval will be clearly marked or labelled EC or ECE approved.