Autolite 104 Spark Plug

Autolite 104 Copper Resistor Spark Plug

Autolite 104 is a copper resistor spark plug built for OE-style form, fit, and function across a wide range of domestic and import applications. It is engineered for quick starts, smooth acceleration, and dependable ignition performance in vehicles such as Ford F-150, Ford Mustang, and Mazda 6 applications.

Key Features

• Copper center electrode core and tip material for consistent ignition response
• 5000 ohm resistor design to help reduce electrical noise
• Tapered ground electrode tip design with a single ground electrode
• Ceramic insulator with mid-projection design
• 14 mm thread diameter, 5/8 in. hex size, and tapered seat
• Pre-gapped at 0.050 in. / 1.30 mm for many listed applications
• OE-style replacement for a broad range of Ford, Mazda, Lincoln, Mercury, Cadillac, Buick, and Chevrolet vehicles

Product Details

The Autolite Copper Resistor Spark Plug line is positioned as an OE-style replacement option for drivers who want factory-like fit and function without changing the original ignition setup. Part number 104 uses a standard copper electrode design, nickel ground electrode core material, and a stud terminal type to support reliable spark delivery. The copper construction is suited to everyday ignition service, while the resistor design helps manage radio-frequency interference in the ignition system.

This part cross-references Autolite 45 and DENSO Auto Parts 5022 for the same application. For fitment searches, Autolite 104 is commonly referenced for Ford F-150, Ford Ranger, and Ford Taurus applications, along with Mazda B3000 and Mazda Tribute models.

Common Issues This Part Can Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent spark delivery
• Reduced throttle response during acceleration
• Ignition noise concerns in resistor-equipped systems
• Maintenance replacement for OE-style spark plug service intervals

Installation Notes and Fitment Tips

Compatible With 1978-2014 applications listed in the fitment data. Verify the required gap for your exact vehicle before installation, since listed applications vary by model and year. Fitment examples include Fits 2000-2010 Ford F-150, N/A; Fits 2005-2011 Ford Focus, N/A; Fits 2003-2005 Mazda 6, N/A; Fits 2006-2011 Cadillac DTS, N/A; and Fits 1999-2007 Ford Taurus, N/A. Some applications note OE half-thread design replacement or dual-plug cylinder requirements, so match the vehicle notes carefully before service.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, and this spark plug is built to OE form, fit, and function expectations for listed applications. Part number 104 is designed as a practical replacement for a wide range of foreign and domestic vehicles.