Fine-Wire Iridium Ignition for Precision and Extended Service Life
The NGK ILTR5D is a Laser Iridium spark plug built for modern engines that demand a fine-wire electrode, low required voltage, and consistent firing across every combustion cycle. The 0.6 mm iridium tip on NGK5476 produces a focused, stable spark kernel that improves combustion efficiency and reduces misfires at idle, cruise, and wide-open throttle. Each box contains four plugs.
Key Features
- Laser-welded 0.6 mm iridium center electrode minimizes required firing voltage
- Platinum-tipped ground electrode resists erosion and maintains gap geometry longer
- Trivalent metal plating on the shell prevents corrosion and eases removal torque
- Corrugated ribs on the insulator prevent flashover in humid conditions
- Copper core aids heat transfer for stable thermal range across driving conditions
- Factory pre-gapped, no adjustment required prior to installation
- Box of 4 covers a complete plug change on most 4-cylinder applications
Specifications
| Detail | Value |
|---|---|
| Part Number (MPN) | ILTR5D / NGK5476 |
| Plug Type | Laser Iridium |
| Center Electrode | Iridium, 0.6 mm |
| Ground Electrode | Platinum-tipped |
| Thread Size | 12 mm |
| Heat Range | 5 |
| Resistor | Yes |
| Quantity | 4 plugs per box |
| UPC | 087295854760 |
What’s Included
- 4x NGK ILTR5D Laser Iridium Spark Plugs
About NGK
NGK Spark Plugs has supplied OEM ignition components to major automakers since 1936. Their Laser Iridium line uses laser-welded fine-wire electrodes produced under strict manufacturing tolerances, delivering ignition performance that matches or exceeds factory specifications over extended service intervals.
Frequently Asked Questions
What vehicles use the NGK ILTR5D spark plug?
The ILTR5D fits a variety of import and domestic engines requiring a 12 mm thread plug. Cross-reference your vehicle’s OEM plug number against NGK5476 using the NGK fitment guide with your year, make, model, and engine code to confirm compatibility before purchasing.
Does the NGK ILTR5D come pre-gapped from the factory?
Yes. Each NGK5476 ships pre-gapped to OEM specification. Do not attempt to regap an iridium plug, as bending the fine-wire electrode can crack the tip and cause the plug to fail.
How long do Laser Iridium plugs last compared to standard copper plugs?
NGK Laser Iridium plugs are rated for up to 100,000 miles under normal operating conditions. Standard copper plugs typically require replacement every 20,000 to 30,000 miles. The iridium tip maintains its gap geometry far longer than copper or standard platinum.
Can I use the ILTR5D in a direct-injection engine?
Yes. The fine-wire iridium center electrode of the NGK ILTR5D is well suited to GDI and port-injected engines where consistent spark placement and low firing voltage are critical to combustion efficiency and emissions control.
What is the installation torque for the NGK ILTR5D?
For a 12 mm plug in an aluminum cylinder head with a new gasket, torque to approximately 13 ft-lb (18 Nm). Always follow your specific engine manufacturer’s torque specification. Over-tightening a small-thread plug in aluminum can strip threads.
How many NGK ILTR5D plugs do I need for my engine?
One box of NGK5476 contains 4 plugs, covering a complete replacement on a 4-cylinder engine. 6-cylinder engines require 6 plugs and 8-cylinder engines require 8 plugs, so order the appropriate number of boxes for your application.
Is the NGK ILTR5D the same as the NGK 5476 part number?
Yes. ILTR5D is the alphanumeric heat range designation and NGK5476 is the numeric catalog reference for the same plug. Both numbers refer to the identical part and can be used interchangeably when searching for this plug.
Will the NGK ILTR5D improve fuel economy?
A worn plug with increased gap resistance requires more ignition voltage and can produce inconsistent combustion. Replacing old plugs with new NGK ILTR5D iridium plugs restores factory combustion efficiency, which can recover fuel economy lost to plug degradation.
Installation Instructions
- Allow the engine to cool fully before beginning plug removal to prevent thread galling in aluminum heads.
- Disconnect the ignition coil or plug wire from the cylinder you are servicing.
- Use a spark plug socket with a rubber insert to remove the old plug by turning counterclockwise.
- Clean the plug bore opening to prevent debris from falling into the cylinder.
- Hand-thread the NGK ILTR5D into the head until snug, then torque to specification.
- Reconnect the ignition coil and repeat for all remaining cylinders.
- Start the engine and verify smooth idle with no misfire or check engine codes.
WARNING: This product can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and reproductive harm. For more information go to www.P65Warnings.ca.gov.
