NGK 5766 Spark Plug

NGK Laser Iridium Spark Plug 5766

NGK Laser Iridium Spark Plug 5766 is built for precise ignition performance in applications that call for a 10 mm, flat-seat spark plug with a .036 pre-gap. It uses an iridium center electrode tip, a nickel ground electrode, and a copper core center electrode to support consistent spark delivery and stable combustion.

As part of the NGK Laser Iridium line, this plug reflects NGK’s OE-focused approach to ignition components for domestic and import vehicles. The 5766 spark plug is also identified by part number IMR9C-9HES and is commonly searched for by drivers looking for an NGK 5766 spark plug or IMR9C-9HES replacement.

Key Features

• Laser Iridium spark plug from NGK
• Part number: 5766 / IMR9C-9HES
• Iridium center electrode tip for precise ignition performance
• Copper core center electrode for efficient heat transfer
• Nickel ground electrode with standard configuration
• Taper-cut ground electrode tip design
• 5000 ohm resistance
• 10.00 mm thread diameter, .75 reach, flat seat
• Pre-gapped to .036
• 5/8 hex size and stud terminal type

Detailed Description

NGK 5766 is a Laser Iridium spark plug engineered for engines that require a fine-wire iridium firing tip and OE-style construction. The iridium center electrode helps maintain a consistent spark path, while the copper core and nickel ground electrode support dependable heat management and combustion stability. With a heat range of 9, this plug is specified for applications that need controlled thermal performance under operating load.

For shoppers comparing NGK 5766, IMR9C-9HES, and related ignition parts, this spark plug is a direct replacement-style option for select vehicles and engine platforms. It is frequently searched in long-tail terms such as NGK 5766 spark plug for Honda Civic and IMR9C-9HES replacement spark plug for import performance applications.

This part cross-references Monroe Shocks & Struts (e.g., 5766) for the same application.

What It Helps Address

• Rough idle caused by worn or fouled spark plugs
• Hard starting from weak or inconsistent ignition output
• Misfire conditions related to degraded plug electrodes
• Reduced throttle response from inefficient combustion
• Fuel economy loss tied to ignition wear

Installation Notes and Tips

Verify the engine calls for a 10 mm, flat-seat spark plug with a .75 reach and .036 pre-gap before installation. Check the existing plug specification against the vehicle service information, and confirm the terminal type and hex size match the ignition setup. For best results, inspect coil boots, plug wells, and threads during service, and install to the manufacturer’s torque specification.

Compatible With select Honda Civic applications and other vehicles that specify NGK 5766 / IMR9C-9HES. Fits 2006-2011 Honda Civic, as listed in the application data for this part.

Quality Assurance

NGK is a long-established OE supplier and manufacturer with extensive North American coverage for domestic and import ignition applications. The brand’s manufacturing focus on original equipment standards supports consistent fit, durability, and operational performance across its spark plug lineup.