Does your HEMI engine sometimes feel sluggish, like it’s not quite running at its best? That frustrating hesitation or slight misfire often points to one small but mighty part: the spark plug. For owners of the powerful 5.7L HEMI, choosing the correct spark plug isn’t just about keeping the engine running; it’s about unlocking that legendary power and efficiency.
The problem is, the market floods you with choices. Should you pick copper, iridium, or platinum? Picking the wrong one can hurt your fuel economy, reduce horsepower, and even damage expensive engine components over time. It’s a confusing choice that can leave any DIY mechanic scratching their head, wondering if they are spending money wisely or just buying the wrong part.
This guide cuts through the confusion. We will break down exactly what your 5.7L HEMI needs to fire perfectly every single time. By the end of this post, you will know the top-rated plugs, understand the technology behind them, and feel confident selecting the perfect set for your truck or car.
Top Spark Plug For 5.7 Hemi Recommendations
- This 16 pack NGK Iridium IX Spark Plug is compatible with Ram 1500 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014, 2013, 2012, 2011 5.7L V8
- Genuine NGK Parts
- Includes original packaging and hardware
- Direct replacement auto parts
- Confirm vehicle fitment with Amazon Confirmed Fit
- Genuine NGK Parts
- REDUCE EMISSIONS AND MISFIRES: This tried-and-true Spark Plug boosts performance, and enables better performance so that your engine runs at its best; The durable shell reliably protects the spark plug from damage, ensuring long-lasting sparking capabilities; The center and ground electrodes promote sharper spark focus for fewer misfires
- IMPROVE IGNITION AND SPARK EFFICIENCY: This Spark Plug employs advanced center and ground electrodes to produce complete and efficient combustion and deliver an outstanding spark for faster, stronger, and more powerful combustion over the life of the spark plug; The damage-tolerant center and ground electrodes minimize spark gap growth and provide greater ignitability and spark efficiency
- TRUST IN NGK NTK: Explore components built by the world leader in the design of spark plugs and oxygen sensors; Their attention to performance excellence is what has differentiated them from the competition and allowed them to be the number one supplier of spark plugs and oxygen sensors
- Genuine Champion Parts
- RELY ON QUALITY SPARK PLUGS: Champion ignition parts keep engines running at their best; Their spark plug catalog provides a diverse set of spark plug types to meet modern engine demands for long-lasting, powerful performance; Built with durable precious metals, Champion Spark Plugs improve performance without the same wear and tear found in competitor plugs
- TRUST IN CHAMPION: Champion has powered more racing legends and won more races than any other spark plug brand; All that success at the track translates to more innovation and a more reliable spark plug for you; With years of expertise in engineering and manufacturing OE components for major automotive manufacturers, Champion understands the importance of a seamless OE-quality replacement part; Their spark plugs adhere to the toughest industry standards for a better fit and longer plug life
- 【VEHICLE FITMENT & FREE VIN CHECK】 Fits 5.7L HEMI V8: for Chrysler 300 (2009-2012, 2014-2023), for Chrysler Aspen (2008-2009), for Dodge Challenger (2009-2022), for Dodge Charger (2009-2023), for Dodge Durango (2008-2009, 2011-2024 GAS), for Dodge Ram 1500/2500 (2009-2010), for Dodge Ram 3500 (2009), for Jeep Commander (2009-2010), for Jeep Grand Cherokee (2009-2023), for Jeep Grand Cherokee L (2021-2024), for Jeep Wagoneer (2022-2023 Nat Asp), for Ram 1500 (2011-2024), for Ram 1500 Classic (2019-2024), for Ram 2500 (2011-2012, 2013-2018 GAS), for Ram 3500 (2011-2018). Includes 8 coils + 16 iridium plugs. NOTE: Years vary by plant – check VIN's 8th digit (EZH/ESB) .
- 【 OEM IGNITION COIL & SPARK PLUG REPLACEMENT 】 Precision-engineered to direct-replace ignition coils UF504, UF-504, 56029129AA, 56029129AB, 56029129AF, 68060346AA, IC584, C1526, 5C1569, and spark plugs LZFR5CI-11 (pre-gapped to exact factory specs). This drop-in kit requires no modifications for these heavy-duty ignition coils and spark plugs.
- 【 HEAVY DUTY IGNITION COILS & PLUGS 】 Upgrade your ride's ignition with our heavy-duty coils and iridium plugs. Built with silicon-steel cores, high-pressure rubber boots, Japan-imported epoxy, and Germany-imported wire, they withstand extreme heat to prevent cracking and voltage leaks. The ultra-fine iridium tips deliver a hotter, more focused spark for maximum fuel efficiency and throttle response—surpassing factory standards.
- 【 FIXES MISFIRES & ROUGH IDLE 】 Is your Check Engine Light (CEL) on due to failing ignition coils? Eliminate hesitation, rough idling, stalling, jerking, backfiring, and sluggish acceleration. This complete 16-piece kit replaces all cylinders at once with brand-new ignition coils and spark plugs to restore that smooth-running engine feel across the entire RPM range.
- 【 EASY DIY & 1-YEAR STANDARD COVERAGE 】 Everything you need in one box: 8 upgraded ignition coils, 16 iridium spark plugs, and an installation guide. Swap them out in your driveway in about 40 minutes with basic tools. Comes with our standard 1-Year Protection Plan to ensure driving right out of the box!
- FITMENT CHECK FIRST - Please confirm your vehicle’s year, make, model, engine, and OE number before purchase. This ignition coil and iridium spark plug kit is designed fit for 2011-2024 Ram 1500 5.7L, 2009-2023 Dodge Charger 5.7L, 2008-2009 Dodge Durango 5.7L, 2011-2024 Dodge Durango 5.7L, 2019-2022 Ram 1500 Classic 5.7L, 2008-2010 Dodge Ram 1500 5.7L, 2008-2023 Jeep Grand Cherokee 5.7L, 2009-2019 Dodge Challenger 5.7L, 2011-2018 Ram 2500 5.7L, and other listed applications
- COMPLETE IGNITION REPLACEMENT KIT - Includes 8 ignition coils and 16 pre-gapped iridium spark plugs for a more convenient ignition system replacement. Replacing both together helps reduce repeated repairs and separate part sourcing. Direct OEM replacement ignition coil and iridium spark plug kit engineered for exact fit by year, make, model, and engine. Recommended spark plug torque: 25-30 N·m (18.44-22.13 ft·lb). Factory pre-lubricated with green dielectric grease for true easy DIY install.
- COMMON IGNITION-RELATED SYMPTOMS - Worn ignition coils or spark plugs may contribute to engine misfire, rough idle, hard starting, hesitation, engine vibration, or check engine light concerns (diagnostic trouble codes including P0300–P0308). This kit may help address these common symptoms when caused by worn ignition components.
- IRIDIUM SPARK PLUGS & DURABLE COILS - Fine-wire iridium spark plugs and epoxy-potted ignition coils are built to support stable ignition and consistent spark delivery. Heat-resistant and vibration-resistant construction helps provide reliable operation for daily driving conditions.
- QUALITY CHECKED & SUPPORT AVAILABLE - Each ignition coil is tested before packaging for consistent performance and dependable operation. Replacement for UF504, C1526, 56029129AA, 56029129AB; 92145, ILZFR5B. Backed by a 2-year warranty and lifetime technical support.
- RESTORE HORSEPOWER & FIX MISFIRES — Worn ignition coils and spark plugs cause power loss, poor gas mileage, rough idle, and engine misfires. Autoexact ignition coil and iridium spark plug set delivers stronger, consistent sparks for efficient combustion—helping restore horsepower, improve throttle response, reduce engine vibration, and support better fuel economy. Helps address common diagnostic trouble codes including P0300–P0308.
- PREMIUM IRIDIUM SPARK PLUGS & OE-QUALITY COILS — Fine-wire iridium spark plugs pre-gapped for up to 40,000 miles. Epoxy-potted ignition coil pack with excellent heat resistance and durability—meets or exceeds OEM specifications for reliable cold starts and smoother acceleration
- PLUG & PLAY INSTALLATION — Direct OEM replacement ignition coil and iridium spark plug kit engineered for exact fit by year, make, model, and engine. No modifications required. Factory pre-lubricated with green dielectric grease for true plug-and-play installation. Recommended torque: 25-30N.m (18.44-22.13 ft·lb). Includes 8 ignition coils and 16 pre-gapped iridium spark plugs. Easy DIY install with basic tools; step-by-step photos on the detail page help save on dealership labor.
- VEHICLE COMPATIBILITY — 2011-2024 Ram 1500 5.7L, 2009-2023 Dodge Charger 5.7L, 2008-2009 Dodge Durango 5.7L, 2011-2024 Dodge Durango 5.7L, 2019-2022 Ram 1500 Classic 5.7L, 2008-2010 Dodge Ram 1500 5.7L, 2008-2023 Jeep Grand Cherokee 5.7L, 2009-2019 Dodge Challenger 5.7L, 2011-2018 Ram 2500 5.7L, and other listed applications. OE & REPLACE NUMBER: UF504, C1526, 56029129AA, 56029129AB; 92145, ILZFR5B. Please confirm your vehicle’s year, make, model, engine, and OE number before purchase.
- TESTED & GUARANTEED — Every ignition coil undergoes rigorous voltage output, insulation, and sealing tests. Backed by 2-year warranty and lifetime technical support for peace of mind.
- Genuine Champion Parts
- TRUST IN CHAMPION: Champion has powered more racing legends and won more races than any other spark plug brand; All that success at the track translates to more innovation and a more reliable spark plug for you; With years of expertise in engineering and manufacturing OE components for major automotive manufacturers, Champion understands the importance of a seamless OE-quality replacement part; Their spark plugs adhere to the toughest industry standards for a better fit and longer plug life
- RELY ON QUALITY SPARK PLUGS: Champion ignition parts keep engines running at their best; Their spark plug catalog provides a diverse set of spark plug types to meet modern engine demands for long-lasting, powerful performance; Built with durable precious metals, Champion Spark Plugs improve performance without the same wear and tear found in competitor plugs
- Genuine Champion Parts
- RELY ON QUALITY SPARK PLUGS: Champion ignition parts keep engines running at their best; Their spark plug catalog provides a diverse set of spark plug types to meet modern engine demands for long-lasting, powerful performance; Built with durable precious metals, Champion Spark Plugs improve performance without the same wear and tear found in competitor plugs
- ENHANCE PERFORMANCE: The sharply-focused flame kernel created by the fine-wire center electrode and v-trimmed ground electrode of the Champion Iridium Spark Plug allows for faster combustion and minimizes quenching and misfires; The Champion Iridium Spark Plugs, designed with the precious metal iridium, withstand high-pressure environments regardless of engine or ignition type
- TRUST IN CHAMPION: Champion has powered more racing legends and won more races than any other spark plug brand; All that success at the track translates to more innovation and a more reliable spark plug for you; With years of expertise in engineering and manufacturing OE components for major automotive manufacturers, Champion understands the importance of a seamless OE-quality replacement part; Their spark plugs adhere to the toughest industry standards for a better fit and longer plug life
Choosing the Best Spark Plug for Your 5.7L Hemi Engine
Your 5.7L Hemi engine is a powerhouse. It needs the right spark plugs to run smoothly and give you the best performance. Picking the wrong plug can cause misfires, poor gas mileage, and even damage. This guide helps you find the perfect spark plug for your truck or car.
Key Features to Look For
When shopping for Hemi spark plugs, focus on these main features:
- **Heat Range:** This is super important. The heat range controls how hot the plug tip gets. Too cold, and it fouls up with carbon. Too hot, and it can cause engine knocking. Most stock Hemi engines use a specific factory heat range. Always check your owner’s manual first.
- **Gap Setting:** The gap is the tiny space between the center and ground electrodes. Modern Hemi engines often require a very specific, small gap (usually around 0.040 inches or sometimes pre-gapped). Incorrect gapping hurts performance.
- **Thread Size and Reach:** Make sure the plug physically fits the cylinder head. Hemi engines use specific thread sizes (like M14x1.25mm) and a certain reach length. Mismatching these causes leaks or damage.
Important Materials Matter
The material used in the center electrode greatly affects how long the plug lasts and how well it fires.
Original Equipment Manufacturer (OEM) plugs often use copper cores because they conduct electricity very well. However, copper wears out fast. For long-term use, look for modern materials:
- **Platinum:** A good upgrade. Platinum center electrodes last much longer than copper. They maintain a consistent gap better over time.
- **Iridium:** This is the top choice for longevity and consistent performance. Iridium is extremely hard and resists wear much better than platinum. These plugs can last over 100,000 miles. They offer the sharpest, most powerful spark.
Factors That Improve or Reduce Quality
Quality spark plugs give you better fuel economy and more power.
What improves quality? High-quality construction means the insulator is strong, preventing voltage leaks. Fine-wire electrodes (like those on iridium plugs) concentrate the spark energy. This helps the fuel burn completely, which is good for horsepower and fuel use.
What reduces quality? Cheap materials cause the electrode to erode quickly. When the gap widens, the coil has to work harder to jump the spark. This can lead to misfires under heavy load (like towing). Also, poorly made shells might corrode inside the engine head, making future removal difficult.
User Experience and Use Cases
How you use your Hemi truck or car changes the best plug choice.
If you mostly drive on the highway or commute daily, an iridium or platinum plug offers excellent “set it and forget it” reliability. You do not need to check the gap for years.
If you heavily modify your Hemi—adding a supercharger, turbocharger, or running special high-octane fuel—you might need a “colder” plug. A colder plug dissipates heat faster. This prevents pre-ignition (engine knocking) caused by the extra heat from forced induction. Always consult a performance tuner for modified engines.
10 Frequently Asked Questions (FAQ) About 5.7L Hemi Spark Plugs
Q: Do I have to use OEM plugs in my 5.7L Hemi?
A: Not necessarily. Many high-quality aftermarket iridium or platinum plugs work just as well or better than the factory plugs. Always match the heat range.
Q: How often should I change the spark plugs in my Hemi?
A: If you use standard copper plugs, change them around every 30,000 miles. If you use iridium plugs, you can usually go 80,000 to 100,000 miles before replacement.
Q: What does “pre-gapped” really mean?
A: Pre-gapped means the manufacturer set the gap close to the required size before shipping. However, shipping can sometimes knock the gap out of alignment. You should always check the gap yourself before installing any plug.
Q: Can I use a spark plug with a larger gap?
A: No. A larger gap requires much more voltage to jump. Your factory ignition coils are only designed for a specific gap. A gap that is too wide causes weak sparks and misfires.
Q: What happens if I use the wrong heat range?
A: A plug that is too hot can cause the electrode to glow, igniting the fuel before the piston is ready. This is dangerous knocking. A plug that is too cold will not burn off deposits and will quickly foul up.
Q: Are iridium plugs worth the extra cost?
A: Yes, for most people. They last significantly longer and provide a more consistent spark, which means better efficiency over the plug’s life.
Q: Can spark plugs improve my gas mileage?
A: Worn-out plugs waste fuel because they cause incomplete combustion. Replacing them with the correct, healthy plugs restores factory efficiency, but new plugs do not magically give you better mileage than when the engine was brand new.
Q: Do I need special tools to change Hemi plugs?
A: Yes. Hemi engines often require a long extension and a specific size spark plug socket, usually one with a rubber boot inside to hold the plug securely when removing or installing it deep in the cylinder head.
Q: My Hemi is running rough after changing plugs. What went wrong?
A: First, check that all spark plug wires or coil boots are fully seated. Second, double-check that you set the gap correctly. Third, ensure the plugs are torqued down properly—not too loose and not overtightened.
Q: Should I use anti-seize compound on the threads?
A: Many modern spark plugs come with special plating and do not require anti-seize. If the manufacturer of your specific plug warns against it, skip it. Overtightening them with anti-seize can damage the cylinder head threads.