2022 Ford F-350 Super Duty Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plugs for your 2022 Ford F-350 Super Duty is crucial for optimal engine performance, fuel efficiency, and longevity. The "right" plug isn't just about thread size; it involves several key factors:

• Heat Range: Spark plugs are designed with a specific heat range, which dictates how quickly the plug dissipates heat from the combustion chamber. A plug that's too "hot" (dissipates heat slowly) can lead to pre-ignition and engine damage, while a plug that's too "cold" (dissipates heat too quickly) can lead to fouling. Always stick to the OEM recommended heat range unless you have specific engine modifications that warrant a change.
• Electrode Metal:
  • Iridium: Most modern vehicles, including the 2022 F-350, come with iridium spark plugs from the factory. Iridium is incredibly durable, offering a very fine electrode tip for a strong, consistent spark and extended service intervals (often 100,000 miles or more). They are the most expensive but offer the best performance and longevity.
  • Platinum: Platinum plugs offer good durability and performance, typically lasting longer than copper plugs (around 60,000-80,000 miles). They use a platinum disc welded to the center electrode and/or ground electrode.
  • Copper: Copper plugs have a large copper core and a nickel-alloy coating. They are excellent conductors of electricity but wear out more quickly due to the softer electrode material, requiring more frequent replacement (every 30,000 miles or so). They are rarely found as OEM on modern trucks but can be used in some modified applications where frequent changes are acceptable.

How to gap a spark plug

Correct spark plug gap is essential for a strong, consistent spark. Too wide, and the spark may be weak or misfire; too narrow, and the spark may be too small or get "blown out" by combustion pressures. While platinum and especially iridium plugs are generally pre-gapped from the factory, it's always a good idea to double-check before installation.

To gap a spark plug, you will need a wire-type spark plug gapping tool. Avoid using disc-style gapping tools on precious metal plugs, as they can damage the fine electrode tip.

1. Measure: Gently insert the appropriate wire gauge into the gap between the center and ground electrodes.
2. Adjust (if necessary): If the gap is too narrow, use the bending tool on the gapper to very gently pry open the ground electrode. If the gap is too wide, carefully tap the ground electrode on a hard, non-abrasive surface to close it slightly. Make small adjustments and re-measure until the correct gap is achieved.
3. Inspect: Ensure the ground electrode is parallel to the center electrode and not twisted.

Replacement procedure tips

Both the 6.2L V8 and 7.3L V8 engines in the 2022 F-350 Super Duty utilize a coil-on-plug (COP) ignition system. This means each spark plug has its own individual ignition coil directly mounted on top of it, eliminating spark plug wires.

• Coil-on-Plug Removal: To access the spark plugs, you'll need to disconnect the electrical connector from each ignition coil and then unbolt the coil (usually a single bolt). Carefully pull the coil straight up to remove it.
• Anti-Seize Debate: There is ongoing debate about using anti-seize on spark plug threads. Ford, like many manufacturers, often advises against it, as it can alter torque readings and potentially lead to over-tightening. Modern spark plugs typically have a special coating on the threads to prevent seizing. If you choose to use anti-seize, use a very small amount and reduce the torque specification by approximately 10-20%.
• Dielectric Grease on Boots: Applying a thin film of dielectric grease inside the spark plug boot (the rubber part that connects to the ceramic insulator of the spark plug) can aid in future removal and help seal out moisture, preventing misfires caused by arcing. Do not apply dielectric grease to the metal terminals.
• Cleanliness: Before removing old spark plugs, it's crucial to blow out any dirt or debris around the spark plug wells with compressed air. This prevents contaminants from falling into the combustion chamber when the old plug is removed.
• Torque Wrench: Always use a torque wrench to tighten spark plugs to the manufacturer's specified value. Over-tightening can damage the spark plug or cylinder head threads, while under-tightening can lead to combustion leaks and potential plug ejection.

Known issues

Fortunately, the 6.2L and 7.3L V8 engines in the 2022 Ford F-350 Super Duty do not have widespread, well-documented spark plug issues similar to the notorious two-piece spark plug breakage on the older Ford 3-valve engines.

However, general best practices still apply:

• Cracked Porcelain: Always handle new spark plugs with care. Dropping a spark plug can crack the ceramic insulator, leading to a misfire. Inspect new plugs carefully before installation.
• Cross-threading: Take your time when starting spark plugs by hand. They should thread in smoothly. If you encounter resistance, stop and re-align the plug. Cross-threading can severely damage cylinder head threads.

Need plugs replaced? Find a shop on Repairius.