Autolite 2546 Spark Plug

Autolite Copper Resistor Spark Plug 2546

Autolite Copper Resistor Spark Plug 2546 is an OE-style replacement built for quick starts, steady ignition performance, and smooth acceleration. It uses a copper center electrode, nickel tip materials, and a 5,000-ohm resistor to support consistent spark delivery in compatible Ford and Mercury applications.

Key Features

• Copper center electrode with nickel tip material for dependable ignition performance
• 5,000-ohm resistor type helps reduce electrical noise in the ignition system
• Extra-long ceramic insulator for stable spark plug operation
• Tapered seat and 14.0 mm thread diameter for OE-style fitment
• Pre-gapped at 0.054 in. / 1.40 mm
• Standard/regular center electrode design with a single ground electrode
• 16 mm hex size and stud terminal type

Product Details

Autolite Copper Resistor Spark Plug 2546 is part of the Autolite Copper Spark Plugs line, which focuses on OE form, fit, and function for a wide range of domestic and foreign vehicles. This spark plug uses a copper core center electrode, nickel ground electrode tip design, and ceramic insulation to support reliable combustion performance in the ignition system. It is a direct-fit style spark plug for applications such as 1984-1987 Ford Thunderbird, 1984-1986 Ford Mustang, and 1984-1987 Mercury Cougar. This part cross-references DENSO Auto Parts 5047 for the same application.

Common Issues This Part Can Address

• Hard starting caused by worn or inconsistent spark plugs
• Rough idle from degraded ignition performance
• Slow throttle response during acceleration
• Misfire symptoms related to plug wear or incorrect gap
• Electrical interference concerns in resistor-equipped ignition systems

Installation Notes and Tips

Verify thread diameter, reach, seat type, and pre-gap before installation. This plug is specified with a 14.0 mm thread, 0.809 in. reach, tapered seat, and 0.054 in. pre-gap. Confirm vehicle-specific service requirements for 1984-1987 Ford Thunderbird, 1984-1986 Ford LTD, 1984-1986 Ford Mustang, 1984-1987 Mercury Cougar, 1984-1986 Mercury Capri, and 1984-1986 Mercury Marquis before installation.

• Fits 1984-1987 Ford Thunderbird, N/A
• Fits 1984-1986 Ford LTD, N/A
• Fits 1984-1986 Ford Mustang, N/A
• Fits 1984-1987 Mercury Cougar, N/A
• Fits 1984-1986 Mercury Capri, N/A
• Fits 1984-1986 Mercury Marquis, N/A

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, with spark plugs engineered around OE-style fit and function. Part number 2546 is built to match the listed application requirements for compatible Ford Mustang, Ford Thunderbird, and Mercury Cougar service.