2015 Nissan Frontier Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2015 Nissan Frontier is crucial for optimal engine performance, fuel efficiency, and longevity. The spark plug's primary job is to ignite the air/fuel mixture in the combustion chamber, and several factors contribute to its effectiveness, including heat range, electrode material, and gap.

Heat Range: Spark plugs are designed with a specific heat range, which refers to their ability to dissipate heat from the combustion chamber. A plug that's too "hot" (dissipates heat slowly) can lead to pre-ignition and engine damage. A plug that's too "cold" (dissipates heat quickly) can cause fouling and misfires. The OEM-specified plugs for your Frontier are engineered for the ideal heat range.

Electrode Metal: The material of the electrode plays a significant role in plug lifespan and performance:

• Iridium: This is the most common material for modern engines, including your 2015 Frontier. Iridium plugs offer exceptional durability and a very fine electrode tip, leading to a hotter, more concentrated spark and extended service intervals (typically 100,000 miles or more). Both the 2.5L and 4.0L engines in your Frontier utilize iridium-tipped spark plugs.
• Platinum: Platinum plugs are also long-lasting, though not quite as durable as iridium. They offer good performance and are often found in vehicles that require longer service intervals than traditional copper plugs.
• Copper: Copper plugs are excellent conductors of electricity but wear out more quickly due to the softer material. They are typically found in older vehicles or high-performance applications where frequent changes are part of a maintenance schedule.

How to gap a spark plug

While most iridium and platinum plugs come pre-gapped from the factory, it's always a good practice to double-check the gap before installation. This is especially true if the plug has been dropped or handled roughly during shipping.

To gap a spark plug, you'll need a wire-type spark plug gapping tool:

1. Identify the correct gap: Refer to the "Quick reference" table above for your specific engine.
2. Use the gapping tool: Slide the correct wire gauge from the tool between the center and ground electrodes. It should have a slight drag.
3. Adjust if necessary:
   • If the gap is too small, gently pry the ground electrode open slightly with the gapping tool.
   • If the gap is too large, gently tap the ground electrode on a hard, non-marring surface to close it. Never bend the center electrode.
4. Re-check: Always re-check the gap after making any adjustments.

Replacement procedure tips

Replacing spark plugs in your 2015 Nissan Frontier is a manageable DIY task, but a few tips can make the process smoother:

• Coil-on-plug removal: Both the 2.5L QR25DE and 4.0L VQ40DE engines in the 2015 Frontier utilize a coil-on-plug ignition system. This means each spark plug has its own ignition coil directly mounted on top of it. To access the plugs, you'll need to disconnect the electrical connector from each coil and then remove the coil mounting bolt. Gently twist and pull the coil straight up to remove it.
• Anti-seize debate: There's an ongoing debate about using anti-seize compound on spark plug threads. Nissan, like many manufacturers, generally recommends against it for modern spark plugs with nickel-plated shells, as it can alter the torque readings and potentially lead to over-tightening. If you do choose to use anti-seize, apply a very thin coat and reduce the torque specification by approximately 10-20%.
• Dielectric grease on boots: Applying a small amount of dielectric grease inside the spark plug boot (the rubber part connecting the coil to the plug) can help prevent moisture intrusion and make future removals easier. It also aids in electrical insulation.
• Torque specs: Always use a torque wrench to tighten spark plugs to the manufacturer's specifications (20 lb-ft / 27 Nm for both engines). Over-tightening can damage the cylinder head threads, while under-tightening can lead to combustion gas leaks and plug premature failure.
• One at a time: To avoid mixing up ignition coils and associated wiring, it's a good practice to replace spark plugs one at a time.

Known issues

The 2015 Nissan Frontier is generally reliable and does not have widely reported recurrent issues specifically related to spark plug design or premature failure like some other manufacturers. Unlike some Ford 3-valve engines, you won't encounter problems with multi-piece spark plug designs breaking during removal.

The key to avoiding spark plug related issues in your Frontier is adhering to the factory-recommended maintenance schedule and using the specified OEM or equivalent aftermarket spark plugs.

Need plugs replaced? Find a shop on Repairius.