Champion 308 Spark Plug

Champion Copper Plus 308 Spark Plug

Champion Copper Plus 308 is a resistor spark plug built for dependable ignition performance across a wide range of older import and domestic applications. Its copper core electrode supports conductivity and heat control, while the nickel center and ground electrode materials are selected for consistent wear characteristics.

Use this Champion spark plug when you need an OE-style replacement for vehicles such as Toyota Tercel, BMW 325i, and Chrysler Intrepid applications that call for the RN12MC4 plug type.

Key Features

• Copper core electrode for improved conductivity and heat management
• Nickel center electrode tip and nickel ground electrode core material
• Resistor design for ignition system noise control
• Flat seat design with a 0.75 in reach
• Pre-gapped at 0.044 in for applications that match the listed specification
• 14 mm thread diameter and 20.65 mm hex size
• Champion Copper Plus line for OE-style service replacement needs

Product Details

Champion 308 is part of the Copper Plus line, a product family focused on practical service life and stable ignition performance. The copper core helps transfer heat away from the firing tip, while the nickel electrode construction supports everyday durability. This spark plug is identified as plug type RN12MC4 and is listed across multiple fitments including 1981-1994 Toyota Tercel, 1987-1991 BMW 325i, and 1994-1995 Dodge Intrepid applications. This part cross-references Autolite 2744 for the same application.

Common Issues This Part Can Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent spark delivery
• Misfire conditions related to excessive plug wear
• Reduced throttle response from degraded ignition performance
• Maintenance replacement for OE-style RN12MC4 spark plug applications

Installation Notes and Tips

Verify the required plug type, thread diameter, reach, seat type, and gap before installation. This plug is pre-gapped at 0.044 in, but vehicle-specific specifications should always be confirmed against the service manual for the exact application. Inspect ignition wires, coils, and plug wells during service to help ensure consistent results after replacement.

Compatible fitment includes 2000-2002 Mitsubishi Mirage, 1994-1995 Dodge Intrepid, 1981-1994 Toyota Tercel, and 1987-1991 BMW 325i applications listed for RN12MC4 service.

Quality Assurance

Champion Copper Plus 308 is built to Champion’s established spark plug specifications, with a copper core design intended to support conductivity and heat control in routine engine service.