Autolite HT15 Spark Plug

Autolite HT15 Platinum Spark Plug Overview

The Autolite HT15 Platinum Spark Plug is built for Ford 3V engines that require OE-style fit, heat range control, and a preset gap. Its high-thread design, fine-wire center electrode, and platinum tip support focused ignition performance in applications such as the Ford F-150, Ford Expedition, and Ford Mustang.

As part of the Autolite Platinum Spark Plug line, the HT15 is engineered around OE dimensions and heat management for specific Ford, Lincoln, and Mercury truck and performance applications. The design emphasizes durability, consistent sealing, and direct replacement fitment for vehicles that call for this exact plug specification.

Key Features

• Platinum center electrode tip with fine-wire center electrode design
• Preset 0.053 in. (1.30 mm) gap; do not regap before installation
• High-thread OE-style design for Ford 3V engine applications
• Nickel ground electrode with tapered tip design
• Copper core center electrode for heat transfer
• 5000 ohm resistor design for ignition system noise control
• Ceramic insulator with extra-long special insulator type
• 16.0 mm thread diameter, 19.5 mm reach, 14 mm / 9/16 in. hex

Detailed Description

Autolite HT15 is a platinum spark plug engineered for specific Ford 3V engine requirements, with OE-style form, fit, and function. The plug’s high-thread construction, tapered seat, and focused ignition design help maintain a reliable seal and stable combustion characteristics in demanding truck and performance applications. This part number is commonly selected for Ford F-150, Ford Expedition, Ford F-250 Super Duty, Ford F-350 Super Duty, Lincoln Navigator, Lincoln Mark LT, and 2005 Ford Mustang applications listed in the fitment data.

This part cross-references Monroe Shocks & Struts (e.g., PZH14F) for the same application.

What This Spark Plug Helps Address

• Misfire conditions caused by worn or incorrect spark plugs
• Hard starting related to weak ignition output
• Rough idle from inconsistent spark delivery
• Loss of throttle response from degraded plug performance
• Heat range mismatch in Ford 3V engine applications

Installation Notes and Tips

• Fits 2008 Ford Expedition, N/A; Black Ignition Coil Boot; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2008 Ford F-150, N/A; Black Ignition Coil Boot; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2008 Ford F-250 Super Duty, N/A; Black Ignition Coil Boot; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2008 Ford F-350 Super Duty, N/A; Black Ignition Coil Boot; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2008 Lincoln Mark LT, N/A; Black Ignition Coil Boot; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2008 Lincoln Navigator, N/A; Black Ignition Coil Boot; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2005-2007 Ford Expedition, N/A; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2004-2007 Ford F-150, N/A; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2007 Ford F-250 Super Duty, N/A; Black Ignition Coil Boot; Alternate Design; Do Not Gap, Gap is Preset; Platinum Spark Plug
• Fits 2005-2007 Ford F-250 Super Duty, N/A; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2007 Ford F-350 Super Duty, N/A; Black Ignition Coil Boot; Alternate Design; Do Not Gap, Gap is Preset; Platinum Spark Plug
• Fits 2005-2007 Ford F-350 Super Duty, N/A; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2006-2007 Lincoln Mark LT, N/A; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2005-2007 Lincoln Navigator, N/A; Do Not Gap, Gap is Preset; OE Style; Platinum Spark Plug
• Fits 2005-2006 Ford F-250 Super Duty, N/A; Alternate Design; Do Not Gap, Gap is Preset; Platinum Spark Plug
• Fits 2005-2006 Ford F-350 Super Duty, N/A; Alternate Design; Do Not Gap, Gap is Preset; Platinum Spark Plug
• Fits 2005 Ford Mustang, N/A; High Thread Spark Plug

Verify engine code and plug specification before installation, especially on Ford 3V engines with alternate design notes. The preset gap should remain unchanged, and the plug should be installed to the manufacturer’s torque specification for the vehicle.

Quality Assurance

Autolite supplies ignition products to the automotive aftermarket and original equipment manufacturers, and the HT15 is built to OE-style dimensions and performance requirements for listed applications. The part number HT15 is also referenced in OE-style interchange data for application matching.