NGK 93858 Spark Plug

Overview

NGK Laser Platinum Spark Plug 93858 is an OE-style ignition replacement built around a platinum center electrode, copper core, and nickel ground electrode. It is specified for compatible Ford, Mercury, and Mazda applications with a 0.048-inch gap and tapered seat design.

Key Features

• Laser Platinum design with a platinum center electrode for stable ignition performance.
• Copper core construction helps manage heat transfer through the plug body.
• 5000 ohm resistance supports consistent secondary ignition operation.
• Standard ground configuration with a single ground electrode.
• Tapered seat, 14 mm thread diameter, and 5/8 hex size.
• Non-removable nut terminal for common ignition wire and coil connections.

Detailed Description

NGK part number 93858 is a Laser Platinum spark plug engineered to match original equipment specifications for select Ford Escape, Ford Fusion, Mercury Mariner, Mercury Milan, and Mazda Tribute applications. The plug uses a platinum tip on the center electrode, a copper core, and a nickel ground electrode to support reliable spark delivery and controlled wear over time. Its 0.048-inch pre-gap and tapered seat make it a direct service replacement for the listed applications, including 2009-2012 Ford Escape, 2011-2012 Ford Fusion, 2009-2011 Mazda Tribute, 2009-2011 Mercury Mariner, and 2011 Mercury Milan. This part cross-references Bosch 8108 and DENSO Auto Parts 4511 for the same application.

NGK 93858 is part of the Laser Platinum line, which focuses on platinum-tipped ignition components built to original equipment standards. For buyers servicing Ford Fusion, Mercury Milan, or other listed vehicles, the part number 93858 provides a fitment-specific replacement option with the correct heat range, reach, and seat style called out in the product data.

What It Is Used For

• Replacing worn spark plugs that cause rough idle.
• Restoring consistent ignition performance after misfire symptoms.
• Addressing hard starting related to plug wear or gap drift.
• Maintaining proper combustion in engines specified for a 0.048-inch gap.
• Servicing OE-equivalent ignition components on listed Ford, Mercury, and Mazda models.

Installation Notes and Tips

Verify the engine application and gap specification before installation. The listed fitments use a 0.048-inch spark plug gap, and the 2010 Ford Fusion and 2010 Mercury Milan entries note OE-equivalent design with a service interval reference. Confirm the tapered seat, 14 mm thread diameter, and 5/8 hex size match the engine specification. Use the correct torque procedure for spark plug installation.

Quality Assurance

NGK states that it is a major OE supplier and manufacturer of spark plugs in North America, with more than 80 years of automotive experience and manufacturing built around original equipment standards. Part number 93858 reflects that OE-focused engineering approach for compatible Ford Escape, Ford Fusion, Mercury Mariner, Mercury Milan, and Mazda Tribute applications.