2025 Ford Ranger Spark Plug Type & Gap

Quick Reference

Why the right plug matters

Choosing the correct spark plug for your 2025 Ford Ranger is crucial for optimal engine performance, fuel efficiency, and longevity. The spark plug is responsible for igniting the air/fuel mixture in the combustion chamber, and a plug that's incompatible with your engine can lead to a cascade of problems.

Several factors determine the "right" plug, including heat range and electrode material. The heat range refers to the plug's ability to dissipate heat. A plug that's too "cold" (dissipates heat too quickly) can lead to carbon fouling, while a plug that's too "hot" (dissipates heat too slowly) can cause pre-ignition and engine damage. Modern engines, like those found in the 2025 Ranger, are often designed for a specific heat range to maintain optimal combustion temperatures.

The electrode material also plays a significant role in plug performance and lifespan.

• Iridium plugs, like the OEM Motorcraft SP-594 specified for the 2025 Ranger, are the most common choice today. They feature a fine-wire iridium center electrode that provides a strong, consistent spark and exceptional durability, often lasting 100,000 miles or more (though Ford recommends 60,000 for these turbocharged engines due to increased stress).
• Platinum plugs offer a good balance of performance and longevity, typically lasting 60,000-80,000 miles. They use a platinum disc welded to the center electrode for extended wear.
• Copper plugs, while excellent conductors, have a much shorter lifespan due to their softer electrode material and are generally not recommended for modern engines like the EcoBoost in the Ranger.

Using the wrong type of plug for your 2025 Ford Ranger can lead to misfires, reduced power, decreased fuel economy, and potential engine damage. Always stick to the manufacturer's recommended specifications or high-quality aftermarket equivalents.

How to gap a spark plug

While many modern iridium spark plugs come pre-gapped from the factory, it's always a good idea to double-check the gap before installation, especially for turbocharged engines like those in the 2025 Ford Ranger. The specified gap for your Ranger's spark plugs is 0.030-0.033 inches (0.76-0.84 mm).

To gap a spark plug, you'll need a spark plug gapping tool. A wire-type feeler gauge is generally preferred for iridium plugs as it minimizes the risk of damaging the delicate fine-wire electrode.

1. Check the gap: Slide the correct size wire gauge 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 away from the center electrode using the gapping tool's adjustment notch. If the gap is too large, carefully tap the ground electrode on a hard, non-abrasive surface to close the gap slightly.

Never pry against the center electrode when gapping, especially with iridium plugs, as this can easily damage the tip and ruin the plug.

Replacement procedure tips

Replacing spark plugs on your 2025 Ford Ranger, featuring coil-on-plug (COP) ignition, requires a few specific considerations:

1. Coil-on-Plug Removal: The Ranger's EcoBoost engines utilize individual ignition coils mounted directly on top of each spark plug. To access the plugs, you'll need to disconnect the electrical connector from each coil and then gently pull the coil straight up and off the plug. A twisting motion can help if the boot is a bit stuck. Inspect the coil boots for cracks or signs of wear and replace them if necessary.
2. Anti-Seize Debate: There is often debate about using anti-seize on spark plug threads. For spark plugs with nickel-plated shells, like many modern plugs (including the OEM Motorcraft parts for your Ranger), manufacturers typically advise against using anti-seize. The plating itself provides sufficient protection against seizing, and anti-seize can alter the torque readings, potentially leading to over-tightening and plug breakage or thread damage. Always refer to the spark plug manufacturer's recommendations. If you choose to use it, apply a very thin layer to only the threads, avoiding the electrode.
3. Dielectric Grease on Boots: A thin layer of dielectric grease inside the spark plug boot (the rubber part that connects the coil to the plug) is highly recommended. This helps prevent moisture entry, aids in easier removal next time, and improves the electrical connection, preventing misfires.
4. Torque is Crucial: Always tighten spark plugs to the manufacturer's specified torque, which is 13-15 lb-ft (18-20 Nm) for the 2025 Ford Ranger. Over-tightening can damage the spark plug threads in the cylinder head or crack the plug's porcelain insulator. Under-tightening can lead to compression leaks and potentially allow the plug to back out.

Known Issues (Not Applicable to 2025 Ford Ranger)

Fortunately, there are no widely reported specific spark plug-related "known issues" for the 2025 Ford Ranger at this time, such as the troublesome two-piece spark plugs found in some older Ford 3-valve engines or ionization-sensing coils in certain GM vehicles. The EcoBoost engines, while high-performance, generally benefit from proper maintenance and adherence to service intervals.

Need plugs replaced? Find a shop on Repairius.