2023 Toyota Tundra Spark Plug Type & Gap Guide

As an ASE-certified master technician, I’ve seen firsthand how crucial standard maintenance is to keeping modern engines running smoothly. The 2023 Toyota Tundra completely revolutionized its powertrain, dropping the legendary 5.7L V8 in favor of the highly advanced 3.4L twin-turbo V6 (V35A-FTS), available in both standard i-FORCE and i-FORCE MAX hybrid configurations. With twin turbos forcing air into the cylinders, spark plug health is more critical than ever.

Below is everything you need to know about the spark plug specifications, gap, and torque for your 2023 Toyota Tundra.

Quick reference

(Note: The i-FORCE and i-FORCE MAX hybrid share the same gas engine and spark plug specifications.)

Why the right plug matters

Modern forced-induction engines like the Tundra's 3.4L twin-turbo operate under immense cylinder pressures and high temperatures. Putting a cheap copper or platinum plug in this engine is a recipe for misfires, poor fuel economy, and potential pre-ignition (engine knock).

The Tundra requires Iridium spark plugs. Iridium is significantly harder and more durable than platinum or copper. The fine-wire iridium center electrode requires less voltage to jump the gap, ensuring a strong, consistent spark even under the heavy boost pressures of the twin turbos. Furthermore, using the correct heat range is critical; a plug that is too hot can cause catastrophic pre-ignition, while a plug that is too cold will foul out. Always stick to the exact OEM Denso or equivalent NGK Laser Iridium part numbers.

How to gap a spark plug

When working with modern iridium spark plugs, extreme caution is required. The iridium tip is tiny (often 0.4mm to 0.6mm) and highly brittle.

1. Check, don't pry: Out of the box, premium Denso and NGK plugs are pre-gapped. Use a wire-style gap gauge or a feeler gauge to verify the gap is at 0.031 inches (0.8 mm). Do not force a coin-style gauge between the electrodes.
2. Adjusting if necessary: If the plug was dropped or out of spec, never pry against the fragile center iridium electrode. Use a dedicated spark plug gapping tool to gently bend the ground strap outward or tap it lightly on a soft surface to close the gap.

Replacement procedure tips

Replacing plugs on the 3.4L V35A-FTS is a bit more involved than the old 5.7L V8 due to the turbo plumbing, but the coil-on-plug (COP) design is straightforward once you have access.

• Clear the way: You will need to remove the engine cover and carefully unbolt the charge pipes and brackets obstructing the ignition coils. Take pictures before disassembling so you know how the vacuum lines route.
• Coil-on-Plug removal: Unplug the electrical connector, remove the 10mm securing bolt, and twist the ignition coil slightly as you pull up to break the seal.
• The Anti-Seize Debate: Do not use anti-seize on modern NGK or Denso spark plugs. They feature a trivalent metal plating that acts as a release agent. Adding anti-seize alters the friction coefficient, making it dangerously easy to over-torque the plug and strip the aluminum cylinder head threads.
• Dielectric Grease: Apply a small pea-sized dab of dielectric grease to the inside of the ignition coil boot before reinstalling. This prevents moisture intrusion and stops the rubber boot from baking onto the porcelain over time.

Known issues

Because this engine utilizes twin turbos, it puts significantly more stress on the ignition system than naturally aspirated engines. As a result, Toyota specifies a very strict 40,000-mile spark plug replacement interval. Ignoring this interval can lead to turbo-damaging misfires or ignition coil failure.

Fortunately, you won't experience the notorious broken plug shells like the older Ford 3-valve engines, provided you remove and install the Tundra's plugs with the engine completely cold. Removing steel plugs from a hot aluminum head drastically increases the risk of thread galling.

Need plugs replaced? Find a shop on Repairius.