2015 Toyota Tundra Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2015 Toyota Tundra is crucial for optimal engine performance, fuel efficiency, and longevity. Spark plugs are not a universal component; they are engineered with specific heat ranges, electrode materials, and designs to match the combustion characteristics of your engine. Using the wrong plug can lead to misfires, reduced power, decreased fuel economy, and potentially engine damage.

Heat Range: This refers to the plug's ability to dissipate heat from the combustion chamber. A plug that is too "cold" (dissipates heat too quickly) can lead to carbon fouling, while a plug that is too "hot" (dissipates heat too slowly) can cause pre-ignition and engine knocking. Toyota engineers have specified a precise heat range for your Tundra's engine to ensure efficient and clean combustion.

Electrode Metal: The material of the center and ground electrodes significantly impacts a plug's lifespan and performance.

• Iridium: This is the most common electrode material for modern Toyota engines, including your Tundra. Iridium is incredibly hard and has a very high melting point, allowing for very fine electrodes. This fine tip concentrates more voltage, leading to a stronger, more consistent spark. Iridium plugs offer exceptional durability and a long service life, typically rated for 100,000 miles or more.
• Platinum: While not as common as iridium in newer Toyota applications, platinum plugs also offer extended life compared to traditional copper. Platinum has good corrosion resistance and a higher melting point than copper.
• Copper: Traditional copper plugs have a large copper core for excellent conductivity, but their electrodes are typically made of nickel alloy. These plugs are inexpensive but wear down quickly, requiring more frequent replacement (typically every 30,000 miles). They are generally not specified for modern engines like your 2015 Tundra.

How to gap a spark plug

Modern iridium spark plugs, like those specified for your 2015 Toyota Tundra, typically come pre-gapped from the factory. It's generally recommended not to adjust the gap on these fine-wire iridium plugs, as it's very easy to damage the delicate electrode. However, if you must check the gap, use a wire-style feeler gauge. Avoid using coin-style gapping tools, as they can put undue stress on the iridium tip. If the gap is incorrect, it's best to replace the spark plug rather than attempt to bend the ground electrode on an iridium plug. The specified gap for all Tundra engines in 2015 is 0.043 inches (1.1 mm).

Replacement procedure tips

Replacing spark plugs on your 2015 Toyota Tundra is a manageable DIY task for experienced mechanics, but there are a few important considerations:

• Coil-on-Plug Removal: Your Tundra uses a coil-on-plug (COP) ignition system, meaning each spark plug has its own individual ignition coil. To access the spark plugs, you'll need to carefully disconnect the electrical connector from each coil and then remove the bolt securing the coil to the valve cover. Gently twist and pull the coil straight up to remove it. Avoid prying, as this can damage the coil or the spark plug tube.
• Anti-Seize Debate: There's ongoing debate regarding the use of anti-seize compound on spark plug threads. Most spark plug manufacturers, including Denso and NGK, recommend against using anti-seize on nickel-plated spark plug threads. The plating itself acts as an anti-seize, and adding more can lead to over-torquing the plug, potentially damaging the cylinder head threads or causing the plug to break during removal. Always follow the spark plug manufacturer's recommendations. If anti-seize is used, reduce the torque value by approximately 20%.
• Dielectric Grease on Boots: Applying a small amount of dielectric grease inside the spark plug boot (the part that connects to the top of the spark plug) can help prevent moisture intrusion and make future removal easier. This grease is an insulator and does not conduct electricity.
• Torque Specifications: Always use a torque wrench to tighten spark plugs to the manufacturer's specified torque. Over-tightening can strip cylinder head threads or damage the spark plug, while under-tightening can lead to poor electrical contact and combustion gas leakage. For the 2015 Toyota Tundra, the torque specification for all engines is 13 lb-ft (18 Nm).

Known issues

Fortunately, the 2015 Toyota Tundra, across all its engine options, is not known for any widespread or unique spark plug-related issues like the Ford 3-valve 2-piece plug breakage. Toyota's engines are generally reliable, and when the correct spark plugs are used and proper maintenance procedures are followed, they provide excellent service.

Need plugs replaced? Find a shop on Repairius.