NGK 1-Step Colder Spark Plug Set

2011–2026 Chrysler / Dodge / Ram / Jeep 6.4L 392 & 6.2L Hellcat

Part #: 2309

Overview

The NGK 1-Step Colder Spark Plug Set is engineered specifically for high-performance Chrysler, Dodge, Ram, and Jeep vehicles equipped with the 6.4L 392 and 6.2L Hellcat engines from 2011 through 2026. Designed to meet the demands of supercharged or nitrous-assisted powertrains, these spark plugs provide enhanced reliability and consistent ignition under extreme combustion conditions. By offering a colder heat range and a fine-wire iridium electrode, they help control engine temperatures, reduce detonation risks, and maintain efficient combustion for improved throttle response and overall performance.

Ideal for enthusiasts and professionals alike, this set of four spark plugs ensures durability and precision in high-horsepower street and competition applications where engine stress is elevated.

Key Features

NGK’s 1-Step Colder Spark Plugs incorporate advanced technology to optimize ignition performance and engine longevity in boosted or nitrous-enhanced setups. Key features include:

• 1-Step Colder Heat Range: Designed to manage increased combustion temperatures in high-output engines.
• Fine-Wire 0.6mm Iridium Electrode: Provides a precise and consistent spark for improved ignition efficiency.
• Copper Core: Enhances heat dissipation to prevent overheating under extreme load conditions.
• Projected-Tip Design: Promotes better fuel burn and quicker throttle response.
• Pure Alumina Ceramic Insulator: Offers superior strength and thermal stability in high-temperature environments.
• Triple-Seal Construction: Prevents combustion gas leakage for reliable performance.
• Anti-Corrosion Trivalent Plating: Protects threads from galling and seizing during installation and removal.
• Taper-Cut Ground Electrode: Enhances flame propagation for efficient combustion.
• Resistor Plug (5k Ohm): Minimizes electrical interference with vehicle electronics.
• Pre-Gapped to 0.031" (0.8mm): Ensures optimal spark gap for consistent ignition.

Construction & Design

Each NGK spark plug is meticulously constructed with a copper core to facilitate rapid heat transfer, critical for maintaining optimal operating temperatures in boosted engines. The fine-wire iridium center electrode, measuring just 0.6mm, delivers a strong and stable spark while resisting wear over time. The pure alumina ceramic insulator provides exceptional mechanical strength and thermal endurance, ensuring the plug withstands the rigors of high-performance combustion cycles.

Additionally, the triple-seal design prevents combustion gases from escaping, preserving engine efficiency and preventing misfires. The corrosion-resistant trivalent plating on the threads safeguards against seizing, making installation and future maintenance hassle-free.

Installation & Fitment

Installation of the NGK 1-Step Colder Spark Plug Set is straightforward and designed to fit directly into factory spark plug locations without modification. Torque specifications are 18–25.3 lb-ft for cast iron cylinder heads and 18–21.6 lb-ft for aluminum heads, ensuring proper sealing and performance. These plugs are pre-gapped to 0.031" (0.8mm), but it is recommended to verify the gap before installation to match specific engine requirements.

This set fits a wide range of vehicles equipped with the 6.4L 392 and 6.2L Hellcat engines, including:

• 2011–2023 Dodge Challenger 6.4L 392
• 2012–2014 Chrysler 300 6.4L 392
• 2023–2024 Chrysler 300 6.4L 392
• 2012–2023 Dodge Charger 6.4L 392
• 2012–2014 Jeep Grand Cherokee 6.4L SRT8
• 2014–2025 Ram 2500 6.4L 392
• 2014–2025 Ram 3500 6.4L 392
• 2015–2023 Dodge Challenger 6.2L Hellcat
• 2015–2023 Dodge Charger 6.2L Hellcat
• 2018–2026 Dodge Durango 6.4L 392
• 2018–2021 Jeep Grand Cherokee 6.2L Trackhawk
• 2021–2026 Dodge Durango 6.2L Hellcat
• 2021–2026 Jeep Wrangler 6.4L 392
• 2022–2024 Jeep Grand Wagoneer 6.4L 392

What's Included

• Set of 16 NGK 1-Step Colder Iridium Spark Plugs (Part #2309)

Ideal For

This spark plug set is perfect for performance enthusiasts and professional tuners who operate Chrysler, Dodge, Ram, or Jeep vehicles with high-output 6.4L 392 and 6.2L Hellcat engines. It is especially suited for applications involving supercharging or nitrous oxide where controlling combustion temperatures and preventing detonation are critical. Whether for street performance, track days, or competitive motorsports, these plugs deliver consistent ignition reliability and durability under demanding conditions.

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.