2018 Toyota Tacoma Spark Plug Type and Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug is crucial for engine performance, fuel economy, and longevity. The spark plug's primary role is to ignite the air-fuel mixture in the combustion chamber. The right plug ensures a consistent and powerful spark at the right time. Key factors to consider are heat range, electrode material, and design.

• Heat Range: This refers to the spark plug's ability to dissipate heat. A plug that is too "hot" can lead to pre-ignition, while a "cold" plug can cause fouling. For the 2018 Toyota Tacoma, using the OEM-specified heat range is essential for optimal combustion.
• Electrode Material: The center electrode of a spark plug can be made from various materials, each with its own advantages:
  • Iridium: The 2018 Tacoma comes from the factory with iridium plugs, which offer the best performance and longest service life. Iridium is an extremely hard and durable precious metal, allowing for a very fine center electrode. This results in a more focused and consistent spark, improving fuel efficiency and throttle response. Iridium plugs, like the recommended Denso and NGK options, typically last for 100,000 miles.
  • Platinum: Platinum plugs are a good mid-range option, offering a longer lifespan than copper plugs but not as long as iridium. They are a suitable replacement if iridium plugs are not available.
  • Copper: Copper plugs have the shortest lifespan but are excellent conductors. They are often used in older vehicles and some high-performance applications but are not recommended for the 2018 Tacoma.

How to gap a spark plug

Properly gapping your spark plugs is a critical step in the replacement process. The "gap" is the distance between the center and ground electrodes. An incorrect gap can lead to misfires, poor fuel economy, and even engine damage. The 2018 Toyota Tacoma requires a gap of 0.043 inches (1.1 mm) for both engine options.

To gap a spark plug, you will need a spark plug gapping tool. These are available at any auto parts store and come in several styles, including a feeler gauge, a wire loop tool, and a ramp-style tool.

1. Gently slide the gapping tool between the center and ground electrodes to measure the current gap.
2. If the gap needs to be adjusted, lightly bend the ground electrode. Never pry against the center electrode, as this can cause it to crack or break.
3. Re-check the gap with your tool and make small adjustments as needed until you reach the specified 0.043 inches.

Replacement procedure tips

The 2018 Toyota Tacoma uses a modern coil-on-plug ignition system, which means each spark plug has its own ignition coil. This design provides a more efficient and reliable spark than older distributor-based systems.

• Coil-on-plug removal: To access the spark plugs, you will first need to remove the ignition coils. This is a straightforward process: disconnect the electrical connector, remove the single bolt holding the coil in place, and then gently twist and pull the coil straight up.
• Anti-seize debate: There is some debate among technicians about whether to use anti-seize compound on spark plug threads. The concern is that it can act as an insulator and also lead to over-torquing. The spark plugs for the 2018 Tacoma come with a special plating on the threads that prevents seizing, so anti-seize is not necessary. If you do choose to use it, apply a very small amount to the threads and reduce the torque by about 10-15%.
• Dielectric grease: It is highly recommended to apply a small amount of dielectric grease to the inside of the spark plug boot before reinstalling the ignition coil. This helps to seal out moisture and prevent corrosion, ensuring a good electrical connection.

Known issues

While some vehicles are known for specific spark plug-related issues, such as the two-piece spark plug design on some Ford 3-valve engines that can break during removal, the 2018 Toyota Tacoma has no such common problems. The Tacoma's engine design and the use of high-quality iridium spark plugs make for a reliable and straightforward spark plug replacement process.

Need plugs replaced? Find a shop on Repairius.