2023 Ram 1500 Spark Plug Type & Gap Specifications

Welcome to your complete spark plug guide for the 2023 Ram 1500. As an ASE-certified master technician, I can tell you that keeping the ignition system healthy on modern trucks is absolutely critical for power, fuel economy, and emissions. Whether you are running the trusty 3.6L Pentastar V6, the legendary 5.7L HEMI V8, or the monstrous 6.2L Supercharged TRX, using the exact right spark plug and specification is non-negotiable.

Quick Reference

Below is the quick reference guide for your 2023 Ram 1500. Note that the 5.7L HEMI requires two spark plugs per cylinder (16 plugs total).

Note: Always verify the exact part number with your VIN, as Mopar frequently supersedes part numbers.

Why the Right Plug Matters

Spark plugs do much more than just ignite the air-fuel mixture. They must survive extreme combustion pressures and temperatures.

• Heat Range: Installing a plug with the wrong heat range can cause major engine damage. A plug that is too "hot" will cause pre-ignition and knocking, while a plug that is too "cold" will foul out rapidly.
• Electrode Metal: The 2023 Ram 1500 utilizes advanced Iridium and Platinum spark plugs from the factory. Iridium is significantly harder and more durable than traditional copper or platinum, allowing for the fine-wire center electrode necessary for a concentrated, efficient spark. Never downgrade to copper plugs on a modern Mopar engine, as they will wear out in a fraction of the required interval and can trigger misfire codes.

How to Gap a Spark Plug

Most modern iridium plugs come pre-gapped, but they can be dropped or bumped during shipping. Always verify the gap before installation.

1. Use a Wire Gauge: Avoid the cheap "coin-style" gappers, as sliding them between the electrodes can easily snap the brittle iridium center wire. Use a wire-style gauge or a dedicated feeler gauge.
2. Light Bend: If the gap needs adjustment, use the bending tool on your gauge to gently pull the ground strap up (to open the gap) or tap it lightly on a soft wood block (to close the gap).
3. Never Pry: Never pry against the center electrode! You will break the precious metal tip.

Replacement Procedure Tips

The 2023 Ram 1500 uses a Coil-on-Plug (COP) ignition system, meaning each cylinder has its own ignition coil sitting directly above the spark plug (or plugs).

• HEMI Twin Plugs: The 5.7L HEMI uses 16 spark plugs—two per cylinder. Take your time, as the rear plugs near the firewall on the passenger side can be a tight squeeze. A swivel socket and a few different extension lengths are your best friends here.
• The Anti-Seize Debate: Mopar, NGK, and Denso advise against using anti-seize on modern spark plugs. Modern plugs have a special trivalent metal plating that prevents seizing in the aluminum cylinder head. Adding anti-seize acts as a lubricant, making it dangerously easy to over-torque the plug and strip the aluminum threads. Install them dry!
• Dielectric Grease: Always apply a small dab of dielectric grease inside the tip of the coil boot before snapping it onto the new plug. This prevents moisture intrusion, stops high-voltage tracking (misfires), and makes removing the boot much easier next time.

Known Issues

• Seized Boots: While we don't have to worry about the infamous Ford 3-valve two-piece spark plug breakage here, Ram trucks can suffer from heat-baked coil boots. If you pull a coil and the rubber boot tears, leaving the bottom half stuck on the spark plug, use a pair of long needle-nose pliers to carefully extract the remaining rubber before trying to get a socket down the tube.
• Ignition Coil Lifespan: While replacing the plugs at 100k miles, carefully inspect the ignition coils. If you see white "lightning" tracks down the side of the boot, the coil is arcing to the block and must be replaced.

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