NGK Spark Plugs HEMI (5.7L, 6.4L)

*Select if your vehicle is SUPERCHARGED or NON-Supercharged before ordering* NGK Iridium IX Spark Plugs - supercharged vehicles (16-pack) The Spark Plug serious enthusiasts rely on. Designed specifically for the performance enthusiast with supercharged vehicles! Iridium IX offers extreme ignitability, improved throttle response, and superior anti-fouling. We recommend the Iridium IX spark plug!  These are a great addition to upgraded RIPP high-performance coil packs!  We've conducted extensive tests on the NGK Iridium IX spark plugs, specifically on a supercharged 5.7-liter Dodge Charger, and the results have exceeded all expectations. In a series of impressive 90! back-to-back dyno passes, we pushed NGK's technology to its absolute limits. Despite the rigorous testing, the spark plugs showcased unparalleled resilience, displaying minimal signs of wear upon removal. They can be used with or without RIPP coil packs.  Each order includes 16 spark plugs.  Pre-Gapped @ .032 (supercharged vehicles) Fine Iridium tip ensures high durability and a consistently stable spark Iridium alloy has extremely high melting point, perfect for today’s high-tech, high-performance engines Trivalent Metal Plating - superior anti-corrosion and anti-seizing properties Outstanding acceleration, high fuel efficiency and durability Ultra strong Iridium electrode designed for higher cylinder pressures and temperatures. Supercharged and Turbocharged application.  Ultimate design, technology and performance.   NGK Ruthenium HX Spark plugs - non-supercharged vehicles (16-pack) New, state-of-the-art NGK Ruthenium plugs designed for engines that demand high ignitability. The Double Fine Electrode (DFE) design promotes spark energy concentration and ignites a wider range of air-fuel ratios, offering improved performance in rich or lean engine conditions. 0.4mm Ruthenium alloy fine wire center electrode and 0.8mm platinum fine wire ground electrode. Trivalent metal platinum provides superior anti-corrosion and anti-seizing properties. Corrugated ribs prevent flashover. Pure alumina silicate ceramic insulator provides superior strength and better heat transfer. Copper core aids in heat removal. We Recommend these plugs for naturally aspirated engines / non-supercharged. Can be used with RIPP coil packs.  Each order includes a set of 16 spark plugs. Gap to .044-.045 (OEM spec. / non-supercharged) Great spark plug for vehicles with upgraded coil packs.  Faster Flame Speed.  Naturally Aspirated Engines ONLY! Dual electrode; Ruthenium center + Platinum tipped ground strap.     Our NGK Spark Plugs fit the following 5.7L V8 vehicles 2009+ RAM 1500 5.7L 2011+ Jeep Grand Cherokee 5.7L 2009+ Jeep Commander 5.7L 2009+ Chrysler 300 5.7L 2009+ Dodge Durango 5.7L 2008+ Dodge Challenger RT 5.7L 2008+ Dodge Charger RT 5.7L  Our NGK Spark Plugs fit the following 6.4L V8 vehicles 2011+ Jeep Grand Cherokee SRT 6.4L 2021+ Jeep Wrangler 392 6.4L 2018+ Dodge Durango SRT 6.4L 2012+ Dodge Charger SRT 6.4L 2012+ Dodge Challenger SRT 6.4L 2012+ Chrysler 300 SRT 6.4L PLEASE NOTE: SPARK PLUGS DO NOT HAVE A WARRANTY.  * Select if your vehicle is SUPERCHARGED or NON-Supercharged before ordering * Pro Tips: Supercharged vehicle - Use RIPP specified gap .032 Non-supercharged vehicle - Use factory-specified gap .044 - .045 Service spark plugs every 30,000 miles.  Check the Spark plug gap! Never install a spark plug without first checking the gap and carefully adjusting if necessary. Ruthenium Plugs have a platinum-tipped ground strap! Carefully gap with proper feeler or proper gapping tools. Iridium / Ruthenium spark plugs have delicate center electrode(s). When gapping, use high-quality gapping tools and feeler gauges. If using a traditional plug gapper, avoid contact with the electrodes at all times. Manipulate the plug's ground strap only! Checking gaps on old plugs that have been removed is commonly overlooked. Recording gap size on an old plug will help determine how often plugs require service. (as plugs wear, the gap will increase in size) Inspect plugs for hairline cracks and damage before installation. Plugs can be mishandled, dropped, and damaged. Carefully inspect a plug's electrode, porcelain, and ceramic portion.  Apply Anti-seize compound to spark plug threads. Apply dielectric grease to coil pack/spark plug wire boot. Always tighten to the manufacturer's recommended torque spec.  Coloration: The color of the insulator nose and electrodes can indicate if an engine is operating smoothly or requires some adjustments. Deposits: Examining deposits on the spark plug can reveal information about the fuel and oil consumption. Reading an older plug removed from an engine can play a crucial roll in engine health!