2018 Ford F-150 Spark Plug Type, Gap & Torque Specs

Quick Reference: 2018 F-150 Spark Plugs

Note: Always double-check the part number and gap specification in your owner's manual or with the parts supplier before installation.

Why the Right Spark Plug Matters

Choosing the correct spark plug is critical for engine performance, fuel economy, and longevity. It's not just about finding a plug that threads in; the engineering behind it matters.

• Heat Range: A spark plug's heat range determines how quickly it dissipates heat from the combustion chamber. An engine that runs hot, like the turbocharged EcoBoost variants, requires a "colder" plug that can transfer heat away more efficiently to prevent pre-ignition (knock). A naturally aspirated engine like the 5.0L V8 runs cooler and uses a "hotter" plug that burns off carbon deposits more effectively.
• Electrode Material: The material of the center and ground electrodes dictates the plug's performance and lifespan.
  • Iridium: Used in all OEM plugs for the 2018 F-150, iridium is an extremely hard, precious metal with a very high melting point. This allows for a very fine-wire center electrode, which provides a more focused and consistent spark. The result is better throttle response, improved fuel efficiency, and a long service life of up to 100,000 miles.
  • Platinum: A step down from iridium, platinum plugs still offer excellent longevity (typically 60,000-80,000 miles) and performance compared to standard copper plugs.
  • Copper: While they provide the best conductivity, copper plugs have a very short lifespan (typically 20,000-30,000 miles) because the metal wears down quickly. They are not recommended for the 2018 F-150, which was designed for long-life iridium plugs.

How to Gap a Spark Plug

Even though most modern iridium plugs come pre-gapped, it is essential to verify the gap before installation. Shipping and handling can easily alter the precise setting. Never trust that a plug is correctly gapped out of the box.

1. Use the Right Tool: Use a feeler gauge or a wire-style spark plug gapper. Avoid the cheap "coin-style" gappers, as they can put pressure on the fragile fine-wire iridium tip and damage it.
2. Check the Gap: Slide the correct wire or blade of your gauge between the center electrode and the ground electrode. It should slide through with slight resistance. If it's too loose or too tight, it needs adjustment.
3. Adjust Carefully: To adjust, gently bend only the ground strap (the curved metal piece over the top). Use a dedicated bending tool or gently tap the end of the plug on a hard surface to close the gap. To open it, carefully pry against the base of the ground strap, never against the center electrode.

Replacement Procedure Tips

The 2018 F-150 uses a modern Coil-On-Plug (COP) ignition system, where each spark plug has its own ignition coil mounted directly on top of it. This makes the replacement process straightforward.

• Coil-On-Plug Removal: After disconnecting the electrical connector, a single 8mm or 10mm bolt holds the coil in place. Once the bolt is removed, the coil and its rubber boot can be twisted and pulled straight up off the spark plug.
• The Anti-Seize Debate: For modern Ford engines with nickel-plated spark plugs (like the Motorcraft plugs specified), Ford officially recommends not using anti-seize compound on the threads. The nickel plating already serves an anti-corrosion purpose. Adding anti-seize can act as a lubricant, leading you to over-torque the spark plug, which can stretch the threads in the aluminum cylinder head. If you choose to use it, reduce the torque spec by 15-20%.
• Dielectric Grease: It is highly recommended to apply a small amount of dielectric grease to the inside of the spark plug boot before reinstalling the coil. This grease does not conduct electricity; instead, it seals out moisture, prevents corrosion on the terminals, and makes it easier to remove the coil next time.

Known Issues

Fortunately for 2018 owners, Ford resolved the infamous two-piece spark plug issue that plagued earlier (pre-2008) 3-valve Triton engines. There are no widespread, systemic issues like plug breakage or cracked porcelain associated with the spark plugs on the 2018 F-150 engine lineup. The primary concerns are related to incorrect installation, such as over-torquing or failing to check the gap, particularly on the high-strung EcoBoost engines where precise spark is critical to preventing engine knock.

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