2020 Toyota Tundra Spark Plug Type, Gap & Torque Guide

The 2020 Toyota Tundra is a workhorse, heavily relying on the legendary 5.7L 3UR-FE V8 engine to deliver its towing and hauling capabilities. As an ASE-certified master technician, I constantly remind truck owners that maintaining the ignition system is critical to keeping that V8 running efficiently. A misfire from a worn spark plug doesn't just cost you at the pump; it can lead to unburned fuel damaging your catalytic converters.

Below is your comprehensive guide to the correct spark plug types, gap specifications, torque values, and replacement tips for the 2020 Toyota Tundra.

Quick reference

For the 2020 model year, the Tundra was exclusively offered with the 5.7L V8 in the US market. Here are the exact factory specifications you need for a tune-up:

Why the right plug matters

Modern engines like the 3UR-FE are highly sensitive to spark plug design, heat range, and electrode materials. The 2020 Tundra comes from the factory equipped with iridium spark plugs.

• Iridium vs. Platinum vs. Copper: Iridium is six times harder and eight times stronger than platinum. This allows for a significantly smaller center electrode, which concentrates the electrical charge and lowers the voltage required to bridge the spark gap. You should never downgrade to standard copper or single-platinum plugs in this engine. Downgrading will trigger misfire codes and drastically reduce the replacement interval from 120k miles down to 30k miles.
• Heat Range: The heat range dictates how quickly the plug transfers heat away from the firing tip into the cylinder head. Using a plug with the wrong heat range can cause pre-ignition (too hot) or carbon fouling (too cold). Stick strictly to the factory Denso or NGK equivalents.

How to gap a spark plug

The Denso and NGK iridium plugs required for the 2020 Tundra come pre-gapped from the factory at 0.043 inches (1.1 mm). However, you should always verify the gap before installation, as plugs can be dropped during shipping.

1. Use the right tool: Do not use a traditional coin-style gapper on iridium plugs, as the fine-wire center electrode is incredibly fragile and can easily snap. Use a wire-type gauge or a feeler gauge.
2. Checking the gap: Gently pass the 0.043" wire through the gap. It should pass through with a slight "drag."
3. Adjusting: If the gap is too tight, use the adjustment tool on the wire gauge to gently bend the ground strap away from the center electrode. Never pry against the iridium center tip.

Replacement procedure tips

Replacing plugs on the 2020 Tundra's 5.7L V8 is a straightforward job, though the rear cylinders near the firewall require a bit of patience.

• Coil-on-Plug (COP) Removal: This engine uses a coil-on-plug ignition system, meaning there is no distributor or spark plug wires. Simply remove the 10mm bolt securing each ignition coil, unplug the electrical connector, and pull the coil straight up.
• Keep it clean: Before removing the old spark plugs, use compressed air to blow debris out of the spark plug wells. You do not want dirt falling into the open combustion chamber.
• The Anti-Seize Debate: Toyota/Denso/NGK plugs feature a special trivalent metal plating that prevents seizing in the aluminum cylinder heads. Therefore, do not use anti-seize on the threads. Adding anti-seize acts as a lubricant and can cause you to over-torque the plugs, risking stripped threads in the aluminum head.
• Dielectric Grease: Apply a small dab of dielectric grease to the inside of the ignition coil boot before reinstalling. This prevents moisture intrusion and stops the rubber boot from vulcanizing to the ceramic porcelain of the new plug.

Known issues

Unlike the infamous Ford 5.4L 3-valve V8s—which were notorious for the two-piece spark plug shells breaking off in the cylinder head—the Toyota 3UR-FE engine does not suffer from plug breakage issues. The plug threads are robust and pull out cleanly.

However, a common issue as these Tundras age is leaking spark plug tube seals. When pulling your ignition coils out, inspect the rubber boots. If you find them soaked in engine oil, the valve cover gaskets and spark plug tube seals have failed. You must replace the gaskets, or the oil will eventually short out the ignition coils, causing a severe misfire.

Need plugs replaced? Find a shop on Repairius.