NGK 4639 Spark Plug

NGK Laser Platinum Spark Plug 4639 Overview

NGK Laser Platinum Spark Plug 4639 is an OE-style ignition component built for precise spark delivery and stable performance. It uses a platinum center electrode, nickel ground electrode, and a 5,000 ohm resistor to support consistent ignition in applications such as the Acura NSX.

The Laser Platinum line focuses on durable electrode construction and OE-matched service characteristics. For Acura NSX owners looking for a direct replacement spark plug, NGK part number 4639 follows the factory-style 0.044 inch gap and flat seat design specified for listed applications.

Key Features

• NGK Laser Platinum Spark Plug, part number 4639
• Platinum center electrode tip for long-life ignition performance
• Nickel ground electrode with standard configuration
• 5,000 ohm resistor helps control electrical noise
• Pre-gapped to 0.044 inch for listed OE applications
• 14 mm thread diameter, 0.75 inch reach, flat seat
• Compatible with Acura NSX fitments listed below

Detailed Description

NGK 4639, also identified as PFR6L-11, is a Laser Platinum spark plug engineered to match OE specifications for select Acura NSX models. The copper core center electrode and platinum tip support reliable ignition characteristics, while the standard ground electrode design and 5/8 inch hex size make it a straightforward replacement for factory-style service. This spark plug is listed for 1997-2005 Acura NSX applications, including 2001-2003 Acura NSX and 2004-2005 Acura NSX fitments.

NGK’s OE manufacturing background and broad coverage across domestic and import vehicles make this spark plug a practical choice for maintenance on the Acura NSX. This part cross-references DENSO Auto Parts 4504 for the same application.

What It Helps Address

• Misfires caused by worn or fouled spark plugs
• Hard starting from weak ignition output
• Rough idle and inconsistent combustion
• Reduced throttle response from degraded spark delivery
• Service replacement needs on Acura NSX ignition systems

Installation Notes and Tips

Verify the vehicle’s required gap before installation; listed applications use a 0.044 inch gap. Confirm the flat seat, 14 mm thread diameter, 0.75 inch reach, and heat range 6 match the engine specification before service. Use proper torque procedures and inspect ignition components for wear or contamination during replacement. Fits 1997-2000 Acura NSX, N/A. Fits 2001 Acura NSX, N/A. Fits 2002 Acura NSX, N/A. Fits 2003 Acura NSX, N/A. Fits 2004-2005 Acura NSX, N/A.

Quality Assurance

NGK is a long-established OE supplier with extensive spark plug manufacturing experience for automotive, motorcycle, marine, and small engine applications. Part number 4639 is built to OE-style standards for durability and operational consistency in the listed Acura NSX applications.