Most Dodge Chargers use long-life spark plugs rated for about 100,000 miles under normal driving; practical replacement typically occurs between 60,000 and 100,000 miles depending on engine and conditions.
In this article, we break down how replacement intervals vary by engine, what signs indicate it’s time for service, and what to consider if you’re doing the job yourself or hiring a shop.
Engine-by-engine intervals
Intervals depend on the engine type and the plug material. The following guidelines reflect common practice across recent Charger models. Always confirm with your owner's manual for your exact year and engine.
- 3.6L Pentastar V6: Modern versions typically use long-life plugs designed for up to about 100,000 miles under normal driving; check the manual for your exact interval.
- 5.7L Hemi V8: Generally rated for around 100,000 miles under normal driving; severe duty or aggressive driving can shorten life.
- 6.4L Hemi (392) V8: Commonly around 100,000 miles under normal conditions; confirm with the manual.
- Hellcat 6.2L supercharged V8 (if your Charger has this engine): Often listed as up to about 100,000 miles under normal use, though heat and boost can accelerate wear; follow the manufacturer’s guidance for your model year.
Note: Plug materials (iridium, platinum) and ignition coil design influence life. If your vehicle uses copper plugs or older designs, intervals may be shorter (often 30,000–60,000 miles). Always verify with your specific model year and engine from the owner's manual or a dealer.
Common signs that spark plugs may need replacement
Worn plugs can show several symptoms that prompt inspection or replacement.
- Rough idle or engine misfires
- Reduced acceleration or sluggish throttle response
- Lower fuel economy
- Difficulty starting or frequent stalling
- Check Engine Light or misfire codes
- Visible wear on plugs or damaged boots/coils
If you notice these signs, have the plugs tested and replaced as needed to restore performance and efficiency.
DIY vs professional replacement: what to know
Whether you replace the plugs yourself or have a shop do it depends on your mechanical comfort and the Charger’s engine family. The steps below outline the general process; always follow the exact torque specs and sequence in your manual.
- Disconnect the negative battery cable and locate the coil-on-plug assemblies for each cylinder.
- Remove the ignition coil(s) one at a time to access the spark plug; avoid twisting the wiring harnesses.
- Carefully thread and remove each spark plug with a proper spark plug socket; inspect the plug and the bore for damage or oil leaks.
- Install new plugs with the correct gap (if not pre-gapped) and torque to the manufacturer’s specification.
- Reinstall the ignition coils, reconnect wiring, and replace any covers or seals; reconnect the battery.
- Start the engine and check for smooth running; scan for codes if necessary.
Note: Some Charger engines have tight access and may require specialized tools or port access for coil packs. If you're unsure, a professional service visit is advised to avoid cross-threading or damage.
Torque and gap basics
Always torque the plugs to the exact specification in your model year's manual or service guide. Many modern plugs come pre-gapped, and gapping them yourself can risk damage. If you’re not confident, rely on a professional to ensure proper seating and sealing to protect the engine.
Summary
In modern Dodge Chargers, spark plugs are designed to last long—typically up to about 100,000 miles under normal driving. Always check your exact model year and engine in the owner's manual or with a dealer. Be mindful of driving style and conditions, and watch for signs of wear that warrant earlier replacement. A professional service can ensure correct torque and sealing, especially on high-performance variants.