2023 Ford F-250 Super Duty Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2023 Ford F-250 Super Duty is crucial for optimal engine performance, fuel efficiency, and longevity. Spark plugs are not "one-size-fits-all," and several factors differentiate them, including heat range, electrode material, and gap.

Heat Range

The heat range of a spark plug dictates how effectively it dissipates heat from the combustion chamber. A "hotter" plug retains more heat, while a "colder" plug dissipates it more quickly. Using a plug with an incorrect heat range can lead to pre-ignition (pinging), detonation, or fouling, all of which can damage your pistons or catalytic converter over time.

For the F-250's powerful gas engines, the factory-specified heat range is designed to handle the combustion temperatures efficiently under various load conditions.

Electrode Material

Modern spark plugs primarily use iridium, platinum, or copper for their electrodes:

• Copper: These are excellent conductors but wear relatively quickly, leading to shorter replacement intervals (typically 30,000 miles). They are rarely used in new vehicles today due to their shorter lifespan.
• Platinum: Platinum plugs offer improved durability over copper, extending replacement intervals to around 60,000 to 80,000 miles. They use a platinum disc welded to the center electrode.
• Iridium: Iridium is the hardest and most durable of the three, allowing for extremely fine electrodes. This thin electrode concentrates the spark, improving ignition efficiency and extending plug life significantly—often to 100,000 miles or more, as seen in your F-250.

Both the 6.8L Windsor V8 and 7.3L Godzilla V8 in your 2023 F-250 Super Duty utilize iridium spark plugs from the factory, hence their extended replacement interval.

How to gap a spark plug

The spark plug gap is the distance between the center and ground electrodes. An incorrect gap can lead to misfires, reduced fuel economy, and poor engine performance.

Your 2023 F-250 Super Duty engines require a precise gap of 0.049-0.053 inches (1.25-1.35 mm). While modern iridium plugs often come pre-gapped, it's always a good practice to verify the gap before installation.

To gap a spark plug:

1. Use a wire-style spark plug gap tool or a feeler gauge: These provide an accurate measurement of the gap.
2. Slide the appropriate wire or blade between the electrodes: It should fit snugly with a slight drag.
3. Adjust the gap if necessary: If the gap is too small, carefully bend the ground electrode outwards using the gapping tool's adjuster. If it's too large, gently tap the ground electrode on a clean, hard surface to close the gap. Never bend or pry on the center electrode.
4. Re-check the gap: Ensure it's within the specified range.

Replacement procedure tips

Replacing spark plugs on your 2023 F-250 Super Duty can be a DIY task for experienced mechanics, but if you're unsure, it's best to consult a professional.

1. Preparation: Ensure the engine is cool to prevent stripped threads. Gather your tools: specific size spark plug socket (typically 5/8" or 9/16"), torque wrench, extensions, ratchet, dielectric grease, and possibly compressed air.
2. Coil-on-Plug (COP) Removal: Your F-250 uses a coil-on-plug ignition system. Each spark plug has an individual ignition coil sitting directly on top of it. Carefully disconnect the electrical connector from each coil and then unbolt the coil (usually a 7mm or 8mm bolt). Gently twist and pull the coil straight up to remove it.
3. Clean Around the Plug: Before unscrewing the old spark plugs, use compressed air to blow away any dirt or debris from around the spark plug wells. This prevents contaminants from falling into the combustion chamber once the plug is removed.
4. Anti-Seize Debate: There is ongoing debate about using anti-seize on spark plug threads. Most modern spark plugs, including those for your F-250, have a special coating on the threads to prevent seizing. Applying additional anti-seize can alter torque readings, potentially leading to overtightening and stripped threads. For your 2023 F-250 Super Duty, it is generally recommended NOT to use anti-seize. Follow the manufacturer's torque specifications precisely.
5. Dielectric Grease: Apply a small amount of dielectric grease inside the spark plug boot (the rubber part of the coil that connects to the plug). This helps seal out moisture, prevents corrosion, and makes future removal easier. Avoid getting grease on the actual electrode or porcelain tip.
6. Torque Matters: Always use a torque wrench to tighten the new spark plugs to the specified 10-14 lb-ft (14-19 Nm). Overtightening can strip threads in the cylinder head or damage the spark plug, while undertightening can lead to combustion gas leaks or the plug vibrating loose.

Known issues

Fortunately, the 6.8L Windsor V8 and 7.3L Godzilla V8 engines in the 2023 Ford F-250 Super Duty do not share the problematic two-piece spark plug design that plagued some earlier Ford 3-valve modular engines (e.g., Triton engines). Therefore, you shouldn't encounter issues with spark plugs breaking upon removal. These newer engines use a more conventional, robust spark plug design.

Need plugs replaced? Find a shop on Repairius.