NGK 7510 Spark Plug

NGK Iridium IX Spark Plug 7510 Overview

NGK Iridium IX Spark Plug 7510 is built for drivers servicing classic Ford, Mercury, and Lincoln applications that call for a tapered-seat 18 mm plug with a 13/16 hex. It combines an iridium center electrode tip with a nickel ground electrode and a copper core for stable ignition performance in a wide range of older domestic engines.

The NGK Iridium IX line focuses on precise ignition characteristics and OE-level manufacturing standards. Part number 7510 is a direct choice for many Ford Bronco, Ford F-150, and Ford F-250 applications where the correct heat range, reach, and gap specification matter.

Key Features

• Iridium center electrode tip material for consistent spark delivery
• Copper core center electrode for efficient heat transfer
• Nickel ground electrode with taper-cut tip design
• Standard ground configuration with one ground electrode
• 5000 ohm resistance
• Tapered seat design, 18.00 mm thread diameter, .429 reach
• Pre-gapped at .040, with vehicle-specific gap adjustments noted in fitment
• Non-removable nut terminal and 13/16 hex size

Detailed Description

NGK 7510, also identified as WR5IX, is an Iridium IX spark plug engineered for a broad range of Ford, Mercury, and Lincoln vehicles from the 1950s through the 1980s. The plug’s iridium tip supports reliable ignition performance, while the copper core and nickel ground electrode help maintain stable operation under everyday driving conditions. This part is commonly searched as an NGK Iridium IX spark plug for Ford F-150, Ford Bronco, and Mercury Cougar applications.

NGK’s long OE manufacturing history and North American coverage make this plug a practical replacement for owners restoring or maintaining older engines that require the correct tapered-seat spark plug specification. This part cross-references Autolite AP45 and AP5125 for the same application.

What This Spark Plug Helps Address

• Hard starting caused by worn or inconsistent spark plugs
• Rough idle from weak ignition output
• Misfire complaints tied to aged plugs or incorrect gap settings
• Reduced throttle response in older carbureted or distributor-equipped engines
• Maintenance replacement for vehicles calling for WR5IX / 7510 specifications

Installation Notes and Fitment Tips

Compatible With select Ford, Mercury, and Lincoln vehicles listed in the fitment data. Confirm the required gap before installation, since notes vary by application and include 0.030, 0.034, 0.044, 0.050, and 0.054 inch specifications. Fits 1979-1986 Ford F-150, N/A; Fits 1966-1974 Ford Bronco, N/A; Fits 1967-1973 Ford Mustang, N/A. Additional fitment includes many Ford E-Series vans, F-Series trucks, Mercury Cougar, Mercury Capri, Mercury Monarch, Mercury Zephyr, and Lincoln Continental applications.

Use the vehicle’s service specification for final gap setting and verify tapered-seat compatibility before installation. The part number 7510 is also listed as WR5IX, which can help when cross-checking catalog references.

Quality Assurance

NGK is a major OE spark plug supplier with decades of automotive manufacturing experience. The brand’s focus on original-equipment standards, durability, and broad vehicle coverage supports dependable replacement selection for classic ignition service.