NGK 6597 Spark Plug - Exhaust Side

NGK Iridium IX Spark Plug 6597 Overview

NGK Iridium IX Spark Plug 6597 is built for drivers who need consistent ignition performance and OE-style fitment across a wide range of import and domestic applications. With an iridium center electrode, copper core, and 5k ohm resistance, this plug is engineered for stable spark delivery and dependable operation in older and performance-oriented engines.

The NGK Iridium IX line focuses on precise ignition characteristics and durable electrode construction. Part number 6597, also identified as BPR5EIX, is a flat-seat spark plug with a .032 inch pre-gap and a 14 mm thread diameter for applications that call for this exact specification.

Key Features

• Iridium center electrode tip for consistent spark performance
• Copper core center electrode for efficient heat transfer
• Nickel ground electrode with taper-cut tip design
• 5,000 ohm resistance for ignition system compatibility
• Pre-gapped at .032 inch for listed applications
• Flat seat, 14 mm thread diameter, .75 inch reach
• Removable nut terminal type
• NGK part number 6597 / BPR5EIX

Detailed Description

NGK 6597 is a spark plug for owners maintaining vehicles such as the Toyota Pickup, Toyota 4Runner, Land Rover Range Rover, and Mitsubishi Mirage with the specified ignition setup. It also appears in fitment for many classic BMW, Mercedes-Benz, Nissan, Mazda, Volvo, Porsche, Jaguar, and Toyota applications, including models that require a .032 inch gap or a dual-plug exhaust-side configuration. This part cross-references DENSO Auto Parts 5305 and Bosch 4018 for the same application.

As part of NGK’s Iridium IX Spark Plug line, this plug combines an iridium firing tip with a copper-core center electrode to support reliable ignition characteristics and long service life in the applications listed. The taper-cut ground electrode design helps maintain a focused spark path, while the 5k resistance supports proper electrical control in compatible ignition systems.

What It Helps Address

• Hard starting caused by worn or inconsistent spark plugs
• Rough idle from weak ignition output
• Misfire conditions related to plug wear or incorrect gap
• Reduced throttle response from degraded spark quality
• Maintenance replacement for vehicles calling for BPR5EIX specifications

Installation Notes and Tips

Verify the engine’s required plug specification, including thread diameter, reach, seat type, and gap, before installation. The listed applications include multiple gap requirements by vehicle, so confirm the exact fitment for your year, make, model, and engine configuration. For dual-plug Nissan applications such as the D21, Pathfinder, 720, and 200SX exhaust-side positions, follow the vehicle-specific service information.

Use the correct torque procedure and inspect ignition components, including wires, coils, and boots, when replacing spark plugs. NGK part number 6597 should be matched to the exact application listed in the fitment data.

Quality Assurance

NGK is a major OE spark plug supplier in North America with more than 80 years of automotive experience. The brand manufactures ignition components for a broad range of automotive, motorcycle, marine, and small engine applications, with a focus on OE standards, durability, and operational performance.