Autolite APP104 Spark Plug

Autolite APP104 Double Platinum Spark Plug

Autolite APP104 is a Double Platinum spark plug built for OE-style fit, stable ignition performance, and longer service life. It uses platinum on both the center and ground electrodes for platinum-to-platinum firing, helping maintain consistent spark quality in demanding daily driving and high-mileage applications.

Compatible With Ford Mustang, Ford F-150, Ford Ranger, Ford Escape, Ford Focus, and other listed applications, this Autolite Double Platinum Spark Plug is a direct replacement choice for many domestic and import vehicles that call for a 14 mm tapered-seat plug with a 0.050 in. gap.

Key Features

• Double platinum electrode design for platinum-to-platinum firing
• Pre-gapped at 0.050 in. / 1.30 mm
• 14 mm thread diameter with tapered seat
• 5/8 in. hex size for standard service tools
• Resistor plug with 5,000 ohm resistance
• Ceramic insulator with mid-projection design
• OE-style form, fit, and function for many applications

Product Details

The APP104 is part of Autolite’s Double Platinum Spark Plug line, which focuses on durable ignition performance for vehicles that use platinum plugs from the factory or benefit from an OE-style upgrade. The platinum center and ground electrode materials help support consistent firing characteristics over time, while the tapered ground electrode tip design and standard regular center electrode design align with common OE service requirements. This part cross-references Bosch 7401 for the same application.

Fitment coverage includes applications such as 2000-2010 Ford F-150, 2005-2011 Ford Focus, 2006-2011 Buick Lucerne, 2006-2011 Cadillac DTS, and 2004-2009 Ford Crown Victoria. The part number APP104 is also used across many Ford, Lincoln, Mercury, Mazda, Cadillac, and Buick vehicles listed in the fitment data.

What It Helps Address

• Hard starting caused by worn spark plug electrodes
• Rough idle from inconsistent ignition firing
• Slower throttle response under normal driving conditions
• Reduced fuel economy related to aged spark plugs
• Misfire concerns tied to plug wear or incorrect gap

Installation Notes and Tips

• Verify the vehicle’s required spark plug gap before installation; listed applications vary by engine and model year.
• Confirm thread diameter, reach, and seat type match the original plug specification.
• Use the vehicle service manual for torque and gap verification procedures.
• Check the ignition system and coil condition if misfire symptoms remain after replacement.
• Review the exact year, make, and model listing before ordering, especially on Ford, Mazda, and Lincoln applications.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, and the APP104 is engineered to meet OE-style expectations for fit and function across its listed applications.