NGK Iridium Spark Plugs

2003–2008 Chrysler/Dodge/Jeep 5.7L Hemi

Part #: 2313

Overview

The NGK 1-Step Colder Iridium Spark Plugs are precision-engineered for high-performance applications, specifically designed to meet the demands of supercharged or nitrous-equipped Chrysler, Dodge, and Jeep 5.7L Hemi engines from 2003 to 2008. These spark plugs feature a colder heat range to effectively manage the elevated combustion temperatures generated by forced induction and nitrous oxide systems, reducing the risk of pre-ignition and detonation while maintaining consistent ignition performance.

Ideal for enthusiasts and professional tuners alike, these plugs deliver reliable spark efficiency and durability under extreme conditions, helping to optimize power output and engine longevity in aggressive tuning and racing setups.

Key Features

Designed to enhance ignition stability and combustion efficiency in boosted or nitrous applications, the NGK 1-Step Colder Iridium Spark Plugs offer the following key features:

• 1-Step Colder Heat Range to combat excessive combustion temperatures in forced induction and nitrous systems
• Fine 0.6mm iridium center electrode for superior spark concentration and consistent flame kernel growth
• Copper core for efficient heat transfer and improved thermal management
• Alumina ceramic insulator providing high strength and excellent dielectric properties
• Extended projection tip design to enhance combustion efficiency and cleaner burn
• Triple-sealed construction ensuring leak-free performance under high cylinder pressures
• Anti-corrosion trivalent metal plating to prevent seizing and corrosion for easier maintenance
• Resistor design (5k Ohm) to reduce electrical interference and protect ignition components
• Tapered seat design with 14mm thread diameter and 1.25mm pitch for precise fitment
• Pre-set gap of 0.043” (1.1mm) optimized for performance ignition

Construction & Design

NGK’s 1-Step Colder Iridium Spark Plugs are built with a robust copper core that efficiently dissipates heat, preventing overheating in high-stress environments. The alumina ceramic insulator provides exceptional mechanical strength and thermal insulation, ensuring durability and consistent performance. The fine iridium center electrode, measuring just 0.6mm, offers a highly concentrated spark that promotes rapid and stable flame propagation, even under elevated cylinder pressures common in boosted engines.

Additionally, the triple-seal construction prevents combustion gas leaks, while the trivalent metal plating resists corrosion and seizing, making these plugs reliable for long-term use in demanding conditions. The extended projection tip further improves combustion efficiency by optimizing the spark’s exposure to the air-fuel mixture.

Installation & Fitment

These spark plugs are designed as direct replacements for a wide range of Chrysler, Dodge, and Jeep vehicles equipped with the 5.7L Hemi engine from 2003 through 2008. Installation requires no modifications and follows standard torque specifications: 10.8–18 lb-ft for cast iron cylinder heads and 7.2–14.5 lb-ft for aluminum heads. Proper torque ensures optimal sealing and performance while preventing damage to the spark plug or cylinder head.

Always verify the gap before installation, although these plugs come pre-gapped to 0.043” (1.1mm), suitable for most high-performance setups.

What's Included

• Set of 4 NGK 1-Step Colder Iridium Spark Plugs (Part #2313)

Ideal For

These spark plugs are perfect for enthusiasts and professionals running supercharged, turbocharged, or nitrous-boosted Chrysler, Dodge, and Jeep 5.7L Hemi engines. They are well-suited for aggressive street tuning, drag racing, and other high-horsepower applications where managing combustion temperatures and maintaining ignition reliability are critical.

Fitment Summary

• 2003–2008 Dodge Ram 1500 5.7L Hemi
• 2003–2008 Dodge Ram 2500 5.7L Hemi
• 2003–2008 Dodge Ram 3500 5.7L Hemi
• 2004–2008 Dodge Durango 5.7L Hemi
• 2005–2008 Chrysler 300C 5.7L Hemi
• 2005–2008 Dodge Dakota 5.7L Hemi
• 2005–2008 Dodge Magnum 5.7L Hemi
• 2005–2008 Jeep Grand Cherokee 5.7L Hemi
• 2006–2008 Dodge Charger 5.7L Hemi
• 2006–2008 Jeep Commander 5.7L Hemi

NGK is one of the most trusted names in ignition, supplying spark plugs, coils, and related ignition/sensor components used across both OEM and aftermarket applications. For performance enthusiasts, NGK’s plug technology and broad coverage make it a reliable baseline upgrade for consistent spark, cleaner burn, and dependable operation under heat and boost.