NGK 5599 Spark Plug

NGK Laser Iridium Spark Plug 5599

NGK Laser Iridium Spark Plug 5599 is an OE-style replacement built for precise ignition performance in a wide range of GM applications. It uses an iridium center electrode, nickel ground electrode, and a 0.060" pre-gap to match factory specifications on many Chevrolet Silverado 1500, GMC Sierra 1500, and Buick models.

The Laser Iridium line focuses on original-equipment fit and durability, backed by NGK’s long history as a major OE spark plug supplier in North America. Part number 5599 is also identified as ITR4A15.

Key Features

• Laser Iridium center electrode for stable spark delivery
• 0.060" pre-gap for OE-style service replacement
• Tapered seat design with 14 mm thread diameter
• 5/8 hex size for common spark plug service tools
• 5000 ohm resistance for ignition system compatibility
• Copper core center electrode and nickel ground electrode construction
• Non-removable nut terminal type

Detailed Description

NGK 5599 is a tapered-seat spark plug with a .708" reach and manufacturer heat range 4. It is built for direct replacement use in many vehicles that call for a 0.060-inch gap, including Chevrolet Express 1500, Chevrolet Silverado 1500, GMC Savana 1500, GMC Sierra 1500, Buick LeSabre, and Pontiac Grand Prix applications. This part cross-references DENSO Auto Parts (e.g., 4511, 5071) for the same application.

For buyers searching for a Chevrolet Silverado 1500 spark plug, GMC Sierra 1500 spark plug, or Buick LeSabre iridium spark plug, NGK 5599 provides an OE-equivalent design intended to match factory service intervals on many listed vehicles. It is also listed under NGK part number ITR4A15.

What It Helps Address

• Hard starting caused by worn spark plug electrodes
• Rough idle from inconsistent ignition firing
• Misfire conditions related to plug wear or gap drift
• Reduced throttle response from weak spark output
• Maintenance replacement for vehicles calling for a 0.060" gap

Installation Notes and Tips

Verify the engine’s required spark plug gap, seat type, and reach before installation. This plug is specified with a 0.060" pre-gap, tapered seat, 14 mm thread diameter, and .708" reach. Use the vehicle service information for torque and removal procedures, and confirm fitment against the exact year, make, model, and engine configuration.

• Fits 2012-2014 Chevrolet Express 1500, N/A
• Fits 2012-2013 Chevrolet Silverado 1500, N/A
• Fits 2010-2011 Chevrolet Silverado 1500, N/A
• Fits 1999-2007 Chevrolet Silverado 1500, N/A
• Fits 2012-2014 GMC Savana 1500, N/A
• Fits 2012-2013 GMC Sierra 1500, N/A
• Fits 2010-2011 GMC Sierra 1500, N/A
• Fits 1999-2007 GMC Sierra 1500, N/A
• Fits 2005-2009 Buick LaCrosse, N/A
• Fits 1997-2008 Pontiac Grand Prix, N/A

Quality Assurance

NGK is a long-established OE spark plug manufacturer serving domestic and import vehicles in North America. The Laser Iridium line is built to original-equipment standards for durability and operational performance across the listed applications.