NGK Iridium Spark Plugs

2005–2011 Chrysler 300C / Dodge Charger / Dodge Magnum / Jeep Grand Cherokee / Dodge Challenger 6.1L SRT8

Part #: 2314

Overview

The NGK 1-Step Colder Iridium Spark Plug Set is engineered specifically for high-performance 6.1L SRT8 engines found in select Chrysler, Dodge, and Jeep models from 2005 to 2011. Designed to meet the demands of forced induction and nitrous oxide applications, these spark plugs provide enhanced combustion control and reliability under extreme conditions. By utilizing a colder heat range, they help reduce the risk of pre-ignition and detonation, common challenges in boosted or nitrous-assisted engines.

Ideal for enthusiasts and professional tuners alike, this set of four plugs delivers consistent ignition performance, improved throttle response, and cleaner combustion for aggressive driving and track use. NGK’s advanced iridium technology ensures long-lasting durability and stable spark delivery, making these plugs a trusted upgrade for performance builds.

Key Features

NGK 1-Step Colder Iridium Spark Plugs incorporate advanced materials and design elements to optimize engine performance and reliability. Key features include:

• 1-Step Colder Heat Range for superior temperature control in forced induction and nitrous applications
• Fine 0.6mm iridium electrode for a precise, concentrated spark and efficient combustion
• Copper core construction for excellent heat dissipation and resistance to detonation
• Extended-projection design to enhance flame travel and combustion efficiency
• Alumina ceramic insulator providing high strength and effective heat management
• Trivalent plating to prevent corrosion and thread seizure
• Triple-seal construction to eliminate combustion gas leakage
• 5k Ohm resistor to reduce electrical interference and ensure stable ignition
• Pre-set gap of 0.050" (1.3mm) optimized for performance tuning

Construction & Design

NGK’s 1-Step Colder Iridium plugs feature a robust copper core that efficiently transfers heat away from the electrode, reducing the risk of engine knock and pre-ignition. The ultra-fine iridium electrode, measuring just 0.6mm, delivers a stronger and more stable spark compared to conventional plugs, promoting cleaner and more complete combustion. The alumina ceramic insulator enhances durability and thermal conductivity, ensuring consistent performance even at high RPMs.

Additionally, the plugs are coated with trivalent plating to resist corrosion and prevent thread seizure during installation or removal. The triple-seal design further ensures that combustion gases do not escape, maintaining optimal cylinder pressure and engine efficiency. The extended-projection electrode design improves flame propagation, which is critical for aggressive tuning and high-performance driving conditions.

Installation & Fitment

This set of four NGK 1-Step Colder Iridium Spark Plugs is a direct fit replacement for the following vehicles equipped with the 6.1L SRT8 engine:

• 2005–2010 Chrysler 300C
• 2006–2010 Dodge Charger
• 2006–2008 Dodge Magnum
• 2006–2011 Jeep Grand Cherokee
• 2008–2010 Dodge Challenger

Installation requires standard spark plug tools and adherence to manufacturer torque specifications: 10.8–18 lb-ft for cast iron heads and 7.2–14.5 lb-ft for aluminum heads. No modifications are necessary, making these plugs a straightforward upgrade for performance enthusiasts.

What's Included

• Set of 16 NGK 1-Step Colder Iridium Spark Plugs (Part #2314)

Ideal For

This spark plug set is ideal for owners and tuners of Chrysler, Dodge, and Jeep SRT8 models who demand reliable ignition performance under boosted or nitrous-assisted conditions. Whether for street performance, track days, or aggressive driving, these plugs help maintain engine safety and responsiveness while maximizing combustion efficiency.

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.