NGK Iridium Spark Plugs

2009–2026 Chrysler, Dodge, Jeep 5.7L Hemi

Part #: 93893

Overview

The NGK 1-Step Colder Iridium Spark Plugs are engineered specifically for high-performance applications involving supercharged or nitrous-boosted engines. Designed to meet the demands of forced induction and nitrous systems, these spark plugs deliver reliable ignition under extreme cylinder pressures and elevated combustion temperatures. Ideal for enthusiasts and professional tuners alike, they help maintain engine stability and efficiency during aggressive tuning and boosted operation.

These plugs are a perfect fit for a wide range of Chrysler, Dodge, and Jeep vehicles equipped with the 5.7L Hemi engine from 2009 through 2026. Whether you drive a Dodge Charger, Ram 1500, Jeep Grand Cherokee, or Chrysler 300C, these spark plugs provide the durability and performance needed for serious power upgrades.

Key Features

Built to withstand the rigors of high-boost and nitrous setups, the NGK 1-Step Colder Iridium Spark Plugs incorporate advanced technology to ensure optimal ignition and combustion efficiency:

• 1-Step Colder Heat Range optimized for forced induction and nitrous applications
• Ultra-fine 0.6mm iridium center electrode for a strong, stable spark and fast flame travel
• Copper core combined with pure alumina ceramic insulator for superior heat dissipation and detonation resistance
• Triple-seal construction to prevent leakage and enhance long-term durability
• Corrosion-resistant trivalent plating to prevent galling and seizing during installation and operation
• Projected tip and taper-cut ground electrode design for efficient flame propagation and improved combustion
• Integrated 5k Ohm resistor to minimize electrical interference with vehicle electronics
• Longevity of approximately 50,000 miles, depending on usage and operating conditions
• Torque specifications: 18–25.3 lb-ft for cast iron heads, 18–21.6 lb-ft for aluminum heads

Construction & Design

NGK’s 1-Step Colder Iridium Spark Plugs feature a copper core that enhances thermal conductivity, allowing the plug to dissipate heat efficiently and reduce the risk of pre-ignition or detonation. The pure alumina ceramic insulator provides excellent electrical insulation and heat resistance, ensuring consistent performance under high-stress conditions.

The iridium center electrode, with its ultra-fine 0.6mm diameter, requires less voltage to generate a strong spark, promoting faster and more complete combustion. The triple-seal design prevents combustion gases from leaking past the plug, maintaining optimal cylinder pressure and protecting the engine’s internals. Additionally, the corrosion-resistant trivalent plating ensures the spark plugs remain easy to install and remove, even after extended use.

Installation & Fitment

These spark plugs are direct replacements for factory units in a broad range of Chrysler, Dodge, and Jeep models equipped with the 5.7L Hemi engine from 2009 to 2026. Installation requires no modifications and can be performed using standard spark plug sockets and torque wrenches. Proper torque application is critical to ensure optimal sealing and performance, with recommended torque values of 18–25.3 lb-ft for cast iron cylinder heads and 18–21.6 lb-ft for aluminum heads.

They are ideal for vehicles running supercharged or nitrous systems, providing enhanced ignition reliability and engine protection under boosted conditions.

What's Included

• Set of 4 NGK 1-Step Colder Iridium Spark Plugs

Ideal For

These spark plugs are perfect for performance enthusiasts and professional tuners who operate Chrysler, Dodge, or Jeep vehicles with the 5.7L Hemi engine and have upgraded to forced induction or nitrous oxide systems. They are especially suited for those seeking improved ignition stability, knock resistance, and combustion efficiency under high cylinder pressures and elevated temperatures.

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.