Autolite 26 Spark Plug

Autolite 26 Copper Resistor Spark Plug

Autolite 26 is a copper resistor spark plug built for OE-style replacement needs across a wide range of classic domestic vehicles. It is engineered for quick starts, smooth acceleration, and dependable ignition performance, with fitment coverage that includes many Chevrolet, Ford, GMC, Buick, Pontiac, Dodge, Lincoln, Oldsmobile, Cadillac, Chrysler, Mercury, and Jeep applications.

Key Features

• Copper center electrode core for responsive ignition performance
• Nickel center and ground electrode tip materials for OE-style service
• 4,000 ohm resistance and resistor design for ignition noise suppression
• Tapered seat design with 14 mm thread diameter and 5/8 in. hex size
• Pre-gapped at 0.045 in. / 1.10 mm
• Ceramic insulator with mid-projection design
• OE form, fit, and function for many foreign and domestic vehicles

Product Details

The Autolite Copper Resistor Spark Plug line is positioned as an OE-style replacement solution for drivers who want straightforward serviceability and consistent ignition performance at a value-focused price point. Part number 26 uses a copper core center electrode to promote strong spark delivery, while the resistor design helps reduce electrical interference in the ignition system. This makes it a practical choice for older Chevrolet Camaro, Ford Mustang, and GMC truck applications where OE-style specifications matter.

This part cross-references Champion Spark Plug 19 and DENSO Auto Parts 5020 for the same application.

Common Problems It Can Help Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle and inconsistent combustion
• Slow throttle response during acceleration
• Ignition noise in resistor-equipped systems
• Loss of fuel economy from degraded spark performance

Installation Notes and Fitment Tips

Compatible With many OE-style applications across 1968-1993 model years. Body fitment examples include Fits 1987-1993 Chevrolet Caprice, N/A; Fits 1987-1992 Pontiac Firebird, N/A; Fits 1980-1985 Ford Mustang, N/A; Fits 1980-1985 GMC Jimmy, N/A; and Fits 1985 Lincoln Town Car, N/A. Always verify the required gap, seat type, and engine specification before installation, since listed applications include multiple OE gap requirements such as 0.035 in., 0.040 in., 0.044 in., 0.045 in., and 0.050 in. depending on vehicle and year.

For best results, confirm the plug matches the vehicle’s original heat range and thread reach. Autolite 26 is pre-gapped at 0.045 in. / 1.10 mm, but some applications may require checking and adjusting to the manufacturer’s specification before use.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, and this spark plug is built to OE-style form, fit, and function standards. The copper resistor design, nickel electrode materials, and ceramic insulator construction support consistent service in a broad range of classic domestic applications.