2023 Ford Ranger — Spark Plug Type & Gap

Keeping your 2023 Ford Ranger running efficiently and producing peak power from its 2.3L EcoBoost engine requires a healthy set of spark plugs. As an ASE-certified master technician, I can tell you that modern turbocharged, direct-injected engines are incredibly demanding on ignition components. The right plug, gap, and torque can make the difference between a smooth-hauling midsize truck and one that suffers from misfires and poor fuel economy.

Quick reference

Note: Turbocharged engines are hard on spark plugs. While Ford states 100,000 miles, many technicians recommend changing them at 60,000 miles to prevent misfires under boost.

Why the right plug matters

Modern engines like the 2.3L EcoBoost require highly specific heat ranges. The heat range determines how fast the plug transfers heat away from the firing tip into the cylinder head. If you use a plug that is too hot, it can cause pre-ignition (knock) which is devastating to a turbocharged engine. If the plug is too cold, it will foul out with carbon deposits.

The electrode metal is equally critical. For the 2023 Ford Ranger, you should only use Iridium or Ruthenium spark plugs (like the Motorcraft SP-578). Unlike traditional copper or standard platinum plugs, iridium is incredibly dense and resists the high-voltage spark erosion required to ignite compressed air-fuel mixtures under turbo boost. Never downgrade to copper or single-platinum plugs in an EcoBoost engine.

How to gap a spark plug

Even if your new Motorcraft or NGK plugs come "pre-gapped," you must verify the gap before installation. Shipping and handling can easily bump the electrode and close the gap.

1. Use the right tool: Avoid cheap coin-style gappers, which can easily snap the brittle iridium center electrode. Use a wire-style feeler gauge.
2. Check the gap: Slide the 0.028 in or 0.030 in wire between the center and ground electrode. It should slide through with a slight "drag."
3. Adjusting the gap: If the gap is too tight, use the bending tool on your gauge to gently pull the ground strap upward. Never pry against the center electrode! If it's too loose, gently tap the ground strap on a soft wooden workbench to close it slightly.

Replacement procedure tips

The 2.3L EcoBoost utilizes a Coil-On-Plug (COP) ignition system, meaning there is no distributor or spark plug wires. Each cylinder has its own ignition coil bolted directly above the spark plug.

• Coil removal: Remove the engine cover to access the coils. Disconnect the electrical connectors carefully—the plastic locking tabs can become brittle from engine heat. Unbolt the single retaining bolt (usually 8mm) and pull the coil straight up.
• The anti-seize debate: Ford and Motorcraft specifically recommend against using anti-seize on the spark plug threads. Modern Motorcraft plugs feature a nickel-plated shell that naturally prevents galling in the aluminum cylinder head. Adding anti-seize alters the friction coefficient, which often leads to over-torquing and cracked porcelain or damaged head threads.
• Dielectric grease: Apply a small dab of dielectric grease to the inside of the coil boot. This prevents moisture intrusion, stops high-voltage arcing to the cylinder head walls, and prevents the rubber boot from baking onto the new spark plug's ceramic body.
• Torque properly: Thread the plugs in by hand using a spark plug socket and an extension. Torque them to exactly 11 lb-ft (15 Nm).

Known issues

Thankfully, the 2.3L EcoBoost does not suffer from the infamous 2-piece spark plug breakage issue that plagued older Ford 3-valve V8s. The plugs in the 2023 Ranger have a standard one-piece shell and extract easily.

However, EcoBoost engines are prone to carbon tracking on the outside of the plug porcelain if the coil boots become compromised or if the plug is installed with a dirty socket. If you pull out an old plug and see faint vertical black scorch marks on the white ceramic, the spark has been flashing over the side of the plug rather than firing in the cylinder. Always replace the coil boot (or the entire coil) if you spot carbon tracking, otherwise, the new plug will immediately suffer the same fate.

Need plugs replaced? Find a shop on Repairius.