2025 Ford Explorer — Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2025 Ford Explorer is critical for optimal engine performance, fuel efficiency, and longevity. Spark plugs are not "one size fits all" components; they are engineered with specific heat ranges, electrode materials, and designs tailored to individual engine characteristics.

• Heat Range: This refers to the plug's ability to dissipate heat. A plug that runs too hot can cause pre-ignition and detonation, leading to engine damage. A plug that runs too cold can foul with carbon deposits, leading to misfires. Your Explorer's engine requires a precise heat range to maintain combustion chamber temperatures within the ideal operating window.

• Electrode Metal: Modern spark plugs utilize various electrode materials, each with distinct advantages:

  • Iridium: This is the preferred material for most late-model vehicles due to its extreme durability and high melting point. Iridium plugs typically have a very fine center electrode, promoting a strong, consistent spark and extended service life (often 100,000 miles or more). Both the 2.3L and 3.0L EcoBoost engines in the 2025 Explorer specify iridium-tipped plugs from the factory.
  • Platinum: Platinum plugs offer good durability and improved performance over copper, with a lifespan generally in the 60,000-100,000-mile range. While not typically OEM for these Explorer engines, some aftermarket options may be platinum.
  • Copper: Copper is an excellent conductor of electricity but is not as durable as iridium or platinum. Copper plugs are more common in older vehicles or those with high-performance applications requiring frequent plug changes. They are not suitable as a direct replacement for your Explorer's EcoBoost engine.

How to gap a spark plug

While many modern iridium spark plugs are "pre-gapped" from the factory, it's always a good practice to verify the gap before installation, especially with aftermarket plugs. Even a slight variation can impact performance.

To gap a spark plug, you'll need a wire-type spark plug gapping tool. Avoid using disc-style gapping tools, as these can damage the delicate iridium electrode.

1. Check the gap: Carefully slide the appropriate wire gauge from your tool between the center and ground electrodes. It should fit snugly with a slight drag.
2. Adjust if necessary: If the gap is too small, gently bend the ground electrode outward with the gapping tool's adjustment notch. If the gap is too wide, carefully tap the ground electrode on a hard, non-abrasive surface (like a wooden bench) to close the gap. Never bend or pry on the center electrode.
3. Re-check: Always re-check the gap after any adjustment to ensure it meets the specified range for your engine.

Replacement procedure tips

Spark plug replacement on your 2025 Ford Explorer, with its coil-on-plug ignition system, is a relatively straightforward DIY task for the mechanically inclined, but attention to detail is crucial.

1. Safety First: Ensure the engine is cool before starting. Disconnect the negative battery terminal to prevent accidental electrical issues.
2. Access: The coil-on-plug design means each spark plug has its own ignition coil mounted directly above it. You'll need to disconnect the electrical connector from each coil and then remove the bolt (usually 8mm or 10mm) securing the coil to the valve cover. Carefully pull the coil straight up to remove it.
3. Anti-Seize Debate: There's ongoing debate about using anti-seize compound on spark plug threads. Ford, like many manufacturers, generally recommends against it for spark plugs with nickel-plated shells, as it can alter torque readings and lead to over-tightening. The Motorcraft spark plugs for your Explorer are typically nickel-plated. If you choose to use it, apply a very thin amount to the threads only and reduce the specified torque by roughly 10-20%.
4. Dielectric Grease: Apply a small amount of dielectric grease to the inside of the spark plug boot (the part of the coil that connects to the plug). This helps seal out moisture, prevents corrosion, and makes future removal easier.
5. Torque Matters: Always use a torque wrench to tighten the new spark plugs to the manufacturer's specification. Overtightening can damage the spark plug and cylinder head threads, while undertightening can cause misfires and allow exhaust gases to escape.
6. Reassembly: Reinstall the ignition coils, ensuring they are seated properly over the spark plugs. Reconnect the electrical connectors and secure the coil bolts. Reconnect the negative battery terminal.

Known issues

Fortunately, the 2025 Ford Explorer's EcoBoost engines do not have any widespread, inherent spark plug related issues such as the problematic two-piece spark plugs found in some older Ford 3-valve engines or unique ionization-sensing coil issues like some GM engines. As long as the correct spark plugs are used and replaced at the recommended intervals, you should expect reliable performance.

Need plugs replaced? Find a shop on Repairius.