Autolite AP646 Spark Plug

Overview of Autolite Platinum Spark Plug AP646

The Autolite Platinum Spark Plug AP646 is engineered for reliable ignition performance in select Buick, Cadillac, Chrysler, Dodge, Oldsmobile, Plymouth, and Pontiac vehicles. Designed with durable materials and precise specifications, this spark plug supports efficient combustion and consistent engine operation.

• Center electrode tip and core made of platinum for enhanced durability
• Tapered ground electrode tip with nickel material for stable spark delivery
• Pre-set gap size of 0.050 inches (1.30 mm) for optimal ignition
• Flat seat type with a 0.750 inch (19.5 mm) reach for proper fitment
• Resistor type spark plug to reduce electrical interference
• Ceramic insulator with mid projection design for heat resistance
• Hex size of 13/16 inch (21 mm) for standard installation tools
• Stud type electrical terminal for secure connection

Features of the Autolite Platinum Spark Plug Line

The Platinum Spark Plug line from Autolite focuses on combining platinum electrode technology with durable construction to provide consistent ignition and longer service life. The AP646 model benefits from this line’s use of platinum on both the center electrode core and tip, which helps maintain a stable spark and resist electrode wear over time. This product line is designed to meet the ignition demands of various domestic vehicles, including models from Buick, Cadillac, Chrysler, Dodge, Oldsmobile, Plymouth, and Pontiac.

Technical Details and Specifications

The AP646 spark plug features a single nickel ground electrode with a tapered tip design, which aids in efficient spark formation. The center electrode is constructed with a standard design using platinum for both the core and tip, enhancing durability and ignition reliability. The spark plug has a flat seat type and a reach of 0.750 inches (19.5 mm), ensuring proper sealing and fitment in compatible engines. The ceramic insulator is mid projection type, providing excellent heat resistance and electrical insulation. Additionally, the resistor built into the plug helps minimize radio frequency interference, protecting vehicle electronics.

Compatible Vehicles and Applications

• Buick models including LeMans and Skylark
• Cadillac models such as DeVille and Eldorado
• Chrysler vehicles including Concorde and Intrepid
• Dodge Caravan and Grand Caravan
• Oldsmobile models like Firenza and Cutlass
• Plymouth Voyager and Grand Voyager
• Pontiac Sunbird and Grand Prix

This spark plug is suitable for secondary ignition systems in these vehicles, providing reliable spark delivery and engine performance.

Common Issues Addressed by Autolite AP646

• Misfiring or rough idling due to worn or damaged spark plugs
• Reduced fuel efficiency caused by inconsistent ignition
• Difficulty starting the engine in cold or damp conditions
• Engine hesitation or loss of power under acceleration
• Electrical interference affecting onboard electronics

Installation Notes and Tips

When installing the Autolite Platinum Spark Plug AP646, ensure the spark plug gap is set to the specified 0.050 inches (1.30 mm) if adjustment is necessary. Use a 13/16 inch (21 mm) socket wrench for proper torque application. The flat seat design requires careful tightening to avoid damage to the cylinder head. It is recommended to inspect the ignition system components and replace spark plugs in sets for balanced engine performance. Always follow vehicle manufacturer torque specifications and installation procedures.

Quality Assurance and Warranty

Autolite spark plugs, including the AP646, are manufactured to meet industry standards for ignition components. The use of platinum electrodes and ceramic insulators ensures durability and consistent performance. While specific warranty details may vary, Autolite products typically come with a limited warranty against manufacturing defects. For detailed warranty information, refer to the product packaging or Autolite’s official documentation.