Autolite APP103 Spark Plug

Autolite APP103 Double Platinum Spark Plug

Autolite APP103 is a Double Platinum spark plug built for OE-style fit, stable ignition performance, and long service life. It uses platinum on both the center and ground electrodes for consistent firing and dependable starts across a wide range of Ford, Mercury, Lincoln, Cadillac, Jaguar, Mazda, Audi, Volvo, Mercedes-Benz, Dodge, and Pontiac applications.

The Double Platinum Spark Plug line is Autolite’s premium OE-replacement option, focused on factory-style form, fit, and function. For drivers searching for an Autolite APP103 spark plug for Ford E-350 Super Duty, Ford Mustang, or Ford Ranger applications, this plug matches common OE gap requirements and secondary ignition specifications.

Key Features

• Double platinum firing surfaces for longer-lasting electrode performance
• Pre-gapped at 0.050 in / 1.30 mm
• 14 mm thread diameter with 5/8 in hex size
• Tapered seat design with mid-projection ceramic insulator
• Resistor-type spark plug for modern ignition systems
• Nickel ground electrode core with platinum tip material
• OE-style replacement for many domestic and import vehicles

Detailed Product Overview

Autolite APP103 is engineered as a direct replacement spark plug for vehicles that call for a platinum-to-platinum design and OE-style secondary ignition performance. The standard center electrode, platinum tip materials, and tapered ground electrode help support consistent spark delivery under everyday driving conditions. This part number is commonly searched as APP103 and is used across multiple fitment groups, including Ford E-Series vans, Ford Explorer, Ford Taurus, Mercury Mountaineer, and Jaguar X-Type applications.

This part cross-references AP Exhaust 7304 and FEL-PRO 1094 for the same application.

What This Spark Plug Helps Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent ignition firing
• Reduced throttle response during acceleration
• Fuel economy loss related to weak spark output
• Maintenance intervals shortened by electrode wear

Installation Notes and Fitment Tips

• Fits 1999-2019 Ford E-350 Super Duty, N/A; verify the listed gap note for your engine application before installation.
• Fits 2003-2014 Ford E-150, N/A; some applications require a 0.044 in (1.1 mm) gap setting.
• Fits 2003-2014 Ford E-250, N/A; confirm the OE gap specification shown in the fitment notes.
• Fits 2007-2012 Ford Escape, N/A; follow the vehicle-specific gap note before use.
• Fits 2005-2008 Mazda 6, N/A; check the application note for the correct gap specification.
• Fits 2006-2009 Cadillac STS, N/A; OE-style spark plug fitment notes call for a 0.050 in (1.3 mm) gap.
• Fits 2003-2008 Jaguar X-Type, N/A; verify the 0.050 in (1.3 mm) gap requirement.

Because fitment notes vary by engine and model year, confirm the vehicle’s OE spark plug gap and thread specifications before installation. The APP103 is a strong match for shoppers comparing Autolite APP103, Ford Mustang spark plugs, and Ford Ranger spark plug replacement options.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, with OE form, fit, and function as a core design target. The APP103 Double Platinum Spark Plug is built to meet the demands of a wide range of domestic and import applications while maintaining consistent ignition performance.