Autolite 45 Spark Plug

Autolite 45 Copper Resistor Spark Plug

Autolite 45 is an OE-style copper resistor spark plug built for quick starts, smooth acceleration, and consistent ignition performance. It uses a copper center electrode, nickel tip materials, and a ceramic insulator to support reliable spark delivery in a wide range of Ford, Mercury, and Lincoln applications.

The Autolite Copper Resistor Spark Plug line focuses on OE form, fit, and function at a value price. Part number 45 follows that approach with a 0.044 in. pre-gap, 18 mm thread diameter, tapered seat, and mid-projection insulator design for direct replacement service on many classic domestic vehicles.

Key Features

• Autolite 45 copper resistor spark plug for OE-style replacement service
• Copper center electrode core with nickel center and ground electrode tip materials
• 0.044 in. / 1.10 mm pre-gap for listed applications
• Resistor design helps reduce electrical noise in the ignition system
• Tapered seat, 18 mm thread diameter, and 13/16 in. hex size
• Ceramic insulator with mid-projection design
• Cross-reference: Anchor 2438 and Valeo 16 for the same application

Detailed Description

Built for secondary ignition service, Autolite 45 is a copper resistor spark plug intended for vehicles that call for an OE-style tapered-seat plug with a 0.044 inch gap. The copper core supports dependable spark transfer, while the nickel electrode materials and resistor construction help maintain stable ignition performance in everyday driving. This part number is commonly searched for Ford F-150 spark plug replacement, Ford Bronco ignition service, and classic Mustang tune-up applications.

Compatible With select Ford Bronco, Ford F-100, Ford F-150, Ford F-250, Ford F-350, Ford Econoline, Mercury Cougar, Mercury Marquis, and Lincoln Continental applications listed in the fitment data. Autolite 45 is also a direct search match for buyers looking for a 1978-1986 Ford truck spark plug, 1965-1974 Mustang spark plug, or OE-style replacement for older Ford and Mercury engines.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent spark delivery
• Misfire symptoms tied to aged ignition components
• Reduced throttle response during acceleration
• Maintenance replacement for OE-style tune-up intervals

Installation Notes and Tips

Verify the required gap, seat type, and thread reach before installation. Autolite 45 uses a tapered seat, 18 mm thread diameter, 0.433 in. reach, and stud terminal type, so it should be matched to the engine specification listed for your vehicle. Check the vehicle application notes carefully, since some Ford models use different gap requirements by year, market, or California emissions calibration.

For best results, inspect ignition wires, distributor components, and coil condition during spark plug service. Confirm the plug gap before installation and follow the vehicle manufacturer’s torque specification.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and OE channels, and this copper resistor spark plug is built to OE-style form, fit, and function standards for the listed applications.