2016 Ford F-250 Super Duty Spark Plug Guide

Quick Reference: Spark Plug Specifications

Note: The 6.7L Power Stroke is a diesel engine and uses glow plugs, not spark plugs. This guide applies only to the gasoline-powered 6.2L V8.

Why the Right Plug Matters

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

• Heat Range: This is a plug's ability to dissipate heat. An incorrect heat range can lead to pre-ignition (too hot) or fouling (too cold). The 6.2L V8 calls for a specific heat range to ensure the plug tip stays hot enough to burn off carbon deposits but cool enough to prevent knocking.
• Electrode Material: The material of the center and ground electrodes determines the plug's lifespan and performance.
  • Iridium: The 2016 F-250's 6.2L V8 came from the factory with iridium-tipped plugs. Iridium is an extremely hard, precious metal with a very high melting point. This allows for a fine-wire center electrode, which provides a more focused and consistent spark, better ignitability, and a service life of up to 100,000 miles.
  • Platinum: A good alternative, platinum plugs offer long life (typically 60,000-90,000 miles) and reliable performance, though they may not match the ultimate longevity of iridium.
  • Copper: Standard copper plugs are excellent conductors and offer great performance, but they wear out much faster, often needing replacement every 20,000-30,000 miles. For a modern engine like the 6.2L V8, using copper plugs would be a significant downgrade.

How to Gap a Spark Plug

Even though most premium plugs like the specified Motorcraft, NGK, or Denso units come pre-gapped, it is essential to verify the gap before installation. Shipping and handling can easily close the gap.

1. Use the Right Tool: A feeler gauge or a dedicated spark plug gapper is the best tool. Avoid the "coin-style" gappers, as they can put pressure on the fragile fine-wire iridium tip and damage it.
2. Measure Carefully: Slide the correct thickness gauge between the center and ground electrodes. It should pass through with a slight amount of drag. For the 6.2L V8, you should be aiming for around 0.044 inches.
3. Adjust Gently: If the gap is too tight or too wide, gently bend the ground electrode (the L-shaped piece curving over the top) with the adjustment tool on your gapper. Never put pressure on or attempt to bend the center electrode.

Replacement Procedure Tips for the 6.2L V8

This engine features a modern coil-on-plug ignition system. The procedure is straightforward, but care must be taken.

• Coil-on-Plug Removal: Each spark plug has its own ignition coil sitting directly on top of it, secured by a single bolt (typically 7mm or 8mm). After removing the bolt and electrical connector, the coil boot can create a strong seal on the plug. Gently twist the coil back and forth while pulling upward to break the seal. Do not yank it, or you may tear the boot.
• The Anti-Seize Debate: The use of anti-seize on spark plug threads is a hotly debated topic. Ford and NGK officially recommend against using it on plugs with a nickel-plated finish (like the OEM SP-526) because it acts as a lubricant. This can lead you to over-torque the plug, potentially stretching the threads in the aluminum cylinder head. The plating itself is designed to prevent seizing. If you do choose to use a small amount, reduce your torque wrench setting by about 15-20%.
• Dielectric Grease: It is highly recommended to apply a small dab of dielectric grease to the inside of the spark plug boot before reinstalling the ignition coil. This grease is an insulator, not a conductor. It prevents voltage leaks, seals out moisture, and makes it much easier to remove the boot next time.

Known Issues

The 2016 F-250's 6.2L V8 avoids the most infamous Ford spark plug issue. The dreaded two-piece spark plug design that would break off in the cylinder head was a problem on the earlier 5.4L and 6.8L 3-valve engines (roughly 2004-2008). The 6.2L V8 uses a conventional, one-piece spark plug design that is far more robust and does not suffer from this widespread issue, making replacement a much less stressful job.

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