NGK 7189 Spark Plug

NGK Iridium IX Spark Plug 7189

NGK Iridium IX Spark Plug 7189 is built for older domestic and import applications that call for a 14 mm, flat-seat plug with a .375-inch reach and a .040 pre-gap. It combines an iridium center electrode with a nickel ground electrode to support consistent ignition performance in classic Chrysler, Dodge, Oldsmobile, Pontiac, Chevrolet, Buick, Cadillac, and Jeep applications.

The NGK Iridium IX line focuses on precise ignition characteristics and OE-style durability. Part number 7189 uses a copper core center electrode, a tapered-cut ground tip, and a 5,000 ohm resistor to help maintain stable spark delivery in the correct heat range for listed applications.

Key Features

• NGK Iridium IX Spark Plug, part number 7189
• Iridium center electrode tip material for precise spark delivery
• Copper core center electrode for efficient heat transfer
• Nickel ground electrode with tapered-cut tip design
• 5,000 ohm resistor for ignition system noise control
• 14 mm thread diameter, .375-inch reach, flat seat
• Pre-gapped at .040 inches for listed applications
• Compatible with many classic Chrysler, Dodge, Oldsmobile, Pontiac, Chevrolet, Buick, Cadillac, and Jeep models

Detailed Description

NGK 7189 is an Iridium IX spark plug engineered around the specifications commonly found in vintage and classic engine applications. The iridium tip supports a focused spark point, while the copper core helps move heat away from the firing end. The standard ground configuration and non-removable nut terminal match the construction used in many OE-style ignition setups. This part cross-references Autolite AP86 for the same application.

Fitment includes applications such as 1950-1969 Chevrolet Bel Air, 1967-1976 Dodge Charger, 1959-1975 Chrysler Imperial, 1967-1971 Pontiac Firebird, and 1966-1971 Jeep CJ5. It also covers select Oldsmobile 98, Cutlass, Delta 88, and Toronado applications with gap-specific notes, including 0.030-inch and 0.040-inch requirements where listed.

What It Helps Address

• Hard starting caused by worn or inconsistent spark plugs
• Misfire concerns from eroded electrode tips
• Rough idle in older ignition systems
• Weak spark delivery in high-mileage classic engines
• Maintenance replacement for vehicles calling for the listed gap and reach

Installation Notes

Verify thread diameter, reach, seat type, and heat range before installation. Set the gap to the vehicle-specific specification shown in the fitment notes, since some applications require 0.030 inch, 0.035 inch, or 0.040 inch settings. Use the correct torque procedure for flat-seat spark plugs and confirm terminal style matches the ignition lead or boot.

Quality Assurance

NGK is a major OE spark plug supplier with more than 80 years of automotive experience and broad coverage across domestic and import applications. Part number 7189 is manufactured to support original-equipment standards for durability and operational performance.