Autolite APP646 Spark Plug

Reliable Ignition with Autolite Double Platinum Spark Plug APP646

The Autolite Double Platinum Spark Plug APP646 is engineered to provide consistent ignition performance for a range of vehicles including Buick, Cadillac, Chrysler, Dodge, Oldsmobile, Plymouth, and Pontiac models. Designed with durable materials and precise specifications, this spark plug supports efficient combustion and engine reliability.

• Double platinum center and ground electrode tips for enhanced durability
• Tapered ground electrode tip design for improved spark efficiency
• Nickel ground electrode core material for strength
• Stud-type electrical terminal for secure connection
• Flat seat type with 14.0 mm thread diameter and 0.750 inch reach
• Ceramic mid-projection insulator for heat resistance
• Resistor type spark plug to reduce electrical interference
• Pre-gapped to 0.050 inch (1.30 mm) for optimal ignition
• Hex size 13/16 inch (21 mm) for standard installation tools

Product Line Overview: Autolite Double Platinum Spark Plug

The Double Platinum Spark Plug line from Autolite features spark plugs with platinum material on both the center and ground electrode tips. This design enhances wear resistance and extends service life compared to conventional spark plugs. The APP646 model benefits from this technology, providing stable ignition and consistent performance across compatible vehicle models.

Detailed Product Description

The APP646 spark plug incorporates a standard center electrode design with a platinum core and tip, paired with a single tapered ground electrode also tipped with platinum. The nickel core ground electrode adds structural integrity, while the ceramic mid-projection insulator ensures effective heat dissipation. The flat seat design and precise thread diameter of 14.0 mm allow for a secure fit in the combustion chamber. Additionally, the resistor built into the plug helps minimize radio frequency interference, supporting vehicle electronics.

Compatible Vehicles and Applications

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

Common Issues Addressed by APP646 Spark Plug

• Misfires and rough idling due to worn electrodes
• Reduced fuel efficiency from inconsistent spark
• Difficulty starting engines in compatible Buick, Cadillac, and Dodge vehicles
• Engine hesitation or power loss under load
• Electrical interference affecting onboard electronics

Installation Notes and Tips

• Verify correct spark plug gap of 0.050 inch (1.30 mm) before installation
• Use a 13/16 inch (21 mm) socket wrench for proper torque application
• Ensure threads are clean and free of debris to prevent cross-threading
• Apply anti-seize compound sparingly on threads if recommended by vehicle manufacturer
• Follow vehicle-specific torque specifications to avoid damage

Quality Assurance and Warranty

Autolite manufactures the APP646 spark plug to meet OEM standards for ignition components. The use of platinum materials on both electrodes contributes to extended service life and consistent performance. While specific warranty details may vary, Autolite products typically come with a limited warranty against manufacturing defects. Consult product documentation or vehicle service guidelines for warranty coverage.