Autolite AP646 Spark Plug

Autolite Platinum Spark Plug AP646 Overview

Autolite Platinum Spark Plug AP646 is an OE-style replacement spark plug built for consistent ignition performance, easier starting, and smoother throttle response. It uses a platinum center electrode and a nickel ground electrode with a tapered tip design to support durable operation in a wide range of Chrysler, Dodge, Plymouth, Pontiac, Buick, Oldsmobile, Cadillac, and related applications.

The Platinum Spark Plug line from Autolite focuses on OE form, fit, and function with a value-oriented replacement option for everyday maintenance. AP646 is a resistor-type plug with a 14.0 mm thread diameter, 0.750 inch reach, flat seat, 13/16 inch hex, ceramic insulator, and mid-projection insulator type.

• Platinum center electrode tip and core material for durable ignition service
• Nickel ground electrode with tapered tip design
• Pre-gapped to 0.050 in. / 1.30 mm
• Resistor-type spark plug for stable ignition system operation
• OE-style dimensions: 14.0 mm thread, 0.750 in. reach, flat seat, 13/16 in. hex
• Compatible with a broad range of Chrysler, Dodge, Plymouth, Pontiac, Buick, Oldsmobile, and Cadillac applications

Detailed Product Information

Autolite AP646 is engineered as a direct-fit platinum spark plug for vehicles that call for a 0.050 inch gap specification, including many Chrysler Town & Country, Dodge Caravan, Dodge Grand Caravan, Plymouth Voyager, Chrysler Intrepid, and Chrysler Concorde applications. It also covers select older Cadillac, Pontiac, Buick, and Oldsmobile models that specify a 0.060 inch gap. This part cross-references Anchor 3142 and Hayden 105 for the same application.

For buyers searching for a replacement spark plug for 1990-2000 Dodge Caravan, 1997-2000 Chrysler Town & Country, or 1993-1997 Dodge Intrepid, AP646 provides the OE-style dimensions and platinum construction needed for routine ignition service. The part number AP646 is also useful when matching service parts across older domestic platforms that use the same thread, reach, and seat configuration.

What This Spark Plug Helps Address

• Hard starting caused by worn or eroded spark plug electrodes
• Rough idle from inconsistent spark delivery
• Reduced throttle response from aged ignition components
• Fuel economy loss related to degraded spark plug performance
• Misfire concerns tied to incorrect gap or worn plug tips

Installation Notes and Fitment Tips

Verify the required gap before installation and confirm the vehicle’s specified plug gap, since fitment notes include both 0.050 inch and 0.060 inch applications. Compatible With 2000 Chrysler Grand Voyager, 1997-2000 Chrysler Town & Country, 1990-2000 Dodge Caravan, 1990-2000 Dodge Grand Caravan, 1997-2000 Plymouth Voyager, and select 1975-1984 Cadillac models listed in the fitment data. Compatible With 1993-1997 Dodge Intrepid, 1993-1996 Chrysler Concorde, and 1987-1988 Pontiac Sunbird applications where the OE-style plug specification matches AP646.

Use the vehicle’s service information to confirm thread diameter, reach, seat type, and terminal style before installation. The AP646 part number should be matched to the engine’s original spark plug specification, especially on older Chrysler, Dodge, Plymouth, Pontiac, Buick, Oldsmobile, and Cadillac platforms.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, and the Platinum Spark Plug line is built around OE-style fit and function. AP646 uses platinum on the center electrode for improved durability versus standard copper plug construction, with materials and dimensions selected for consistent service in everyday driving.