Autolite AP5145 Spark Plug

Autolite Platinum Spark Plug AP5145

Autolite Platinum Spark Plug AP5145 is an OE-style replacement built for consistent ignition performance, easier starting, and improved fuel economy compared with standard copper plugs. It uses a platinum center electrode and a nickel ground electrode to support durability in everyday driving, including Ford Mustang, Thunderbird, Taurus, and Mercury Cougar applications.

Key Features

• Platinum center electrode and platinum tip for longer service life than standard copper designs
• 0.054 in. pre-gap for the specified OE-style application
• Resistor spark plug with 4,000 ohms resistance
• Tapered seat design with 14.0 mm thread diameter and 20.5 mm reach
• Extra-long ceramic insulator for stable ignition performance
• Stud terminal type with a 5/8 in. hex size for standard service tools

Product Details

The Autolite Platinum Spark Plug line focuses on OE form, fit, and function for a wide range of domestic and foreign vehicles. AP5145 follows that approach with a platinum center electrode, nickel ground electrode core, and tapered ground electrode tip design to support reliable spark delivery and reduced wear over time. This part number is listed across multiple Ford and Mercury applications, including 1994-1997 Ford Mustang, 1996-1997 Ford Thunderbird, and 1993-1997 Mercury Cougar. This part cross-references AMS Automotive 6105 and Valeo 11 for the same application.

What It Helps Address

• Hard starting caused by worn or inconsistent spark plugs
• Rough idle from degraded ignition performance
• Slow throttle response during acceleration
• Reduced fuel economy linked to weak spark delivery
• Service intervals shortened by faster electrode wear

Installation Notes and Tips

Verify the vehicle’s required thread diameter, reach, seat type, and gap before installation. AP5145 is specified with a 0.054 in. pre-gap, but final installation should always follow the vehicle service specification. Confirm the tapered seat and stud terminal style match the original plug before use. This spark plug is listed for many Ford Mustang, Ford Thunderbird, Ford Taurus, Mercury Cougar, and Mercury Sable applications, so checking year-specific fitment is important.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, and this Platinum Spark Plug is built to OE-style dimensions and performance targets for the listed applications.