2025 International MV Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2025 International MV is not just about getting the engine to run; it's about optimizing performance, fuel efficiency, and longevity. The spark plug is a small but critical component responsible for igniting the air-fuel mixture in your engine's cylinders. Its design, specifically the heat range and electrode material, plays a vital role.

Heat Range

Spark plugs are designed with a specific "heat range," which refers to their ability to dissipate heat. A "cold" plug dissipates heat quickly, preventing pre-ignition and detonation in high-performance or hard-working engines. A "hot" plug retains more heat, burning off deposits and preventing fouling in engines that run at lower temperatures or primarily short trips. Using the wrong heat range can lead to engine damage or poor performance. The Cummins B6.7 in the International MV is a heavy-duty diesel engine, and as such, it does not utilize spark plugs.

Electrode Metal (Iridium vs. Platinum vs. Copper)

While spark plugs are not used in diesel engines, it's helpful to understand the different electrode materials commonly found in gasoline spark plugs:

• Copper: These are the most common and least expensive. Copper is an excellent conductor but wears relatively quickly, requiring more frequent replacement.
• Platinum: Platinum plugs offer better durability and a longer lifespan than copper. They are often used as OEM plugs in many modern gasoline vehicles.
• Iridium: Iridium is the hardest and most durable electrode material. Iridium plugs offer the longest lifespan, superior ignitability, and consistent performance. They are typically found in high-performance engines and those with extended service intervals.

How to gap a spark plug

While spark plugs are not used in the 2025 International MV's Cummins B6.7 diesel engine, for general knowledge on spark plug gapping, here's the procedure:

1. Consult Specifications: Always refer to the manufacturer's specifications for the correct gap setting. This information is usually found in your owner's manual or a service manual.
2. Use a Gapping Tool: A wire-type spark plug gapping tool is recommended. Avoid using a ramp-style tool on fine-wire iridium or platinum plugs, as it can damage the electrode.
3. Measure the Gap: Carefully slide the correct wire gauge from your gapping tool between the center and ground electrodes. It should have a slight drag.
4. Adjust if Necessary: If the gap is too small, gently bend the ground electrode outwards with the gapping tool's adjuster. If it's too wide, carefully tap the ground electrode on a hard, flat surface to close the gap. Be very gentle, especially with fine-wire plugs, to avoid damaging the electrode.
5. Re-check: Always re-check the gap after adjustment to ensure accuracy.

Replacement procedure tips

As the 2025 International MV uses a diesel engine (Cummins B6.7), it does not have spark plugs. Therefore, a spark plug replacement procedure is not applicable.

Known issues

The Cummins B6.7 diesel engine in the 2025 International MV is renowned for its durability and reliability. As a diesel engine, it does not suffer from common spark plug-related issues found in gasoline engines, such as cracked porcelain, broken plug shells (like those seen in some Ford 3-valve engines), or ionization-sensing coil problems (found in some GM 5.3L engines).

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