E3 Spark Plugs

05-10 Dodge Ram /  Durango / Jeep Grand Cherokee 5.7L Hemi & 6.1L SRT8

E3.66

The E3.66 Automotive Spark Plug is engineered for high-performance vehicle engines found in select vehicle. Built with advanced ignition technology, it features E3’s patented DiamondFIRE electrode design, delivering superior combustion efficiency, faster flame propagation, and enhanced power output. This unique design generates intense turbulence in the combustion chamber, leading to better throttle response, fuel economy, and cleaner emissions. Constructed with a resistor, 5/8" hex size, and a fixed DiamondFIRE gap, the E3.66 plug fits 14mm thread diameter applications with a 1.000" reach and taper seat, making it a perfect fit for late-model HEMI V8 engines. It’s not just about power—it’s about long-lasting performance. Backed by a 5-year or 100,000-mile guarantee, the E3.66 plug ensures peace of mind for the road ahead.

• Advanced Electrode Design: Patented DiamondFIRE side wire promotes complete combustion for more power and better efficiency.
• Improved Performance: Increases horsepower, enhances throttle response, and reduces hydrocarbon emissions.
• Durability: 5-year / 100,000-mile limited warranty.

Construction:

• Resistor Type
• Thread Diameter: 14mm
• Thread Reach: 1.000”
• Seat Type: Taper
• Hex Size: 5/8”
• Tip: Fixed Gap – not adjustable
• Enhanced Heat Transfer: Three-legged design stabilizes the electrode for reliable ignition and heat dissipation.

E3 Spark Plugs uses its patented DiamondFIRE design to target efficient combustion and consistent ignition performance across automotive and racing applications. For performance builds, a quality spark plug choice can support clean burn characteristics and reliability—especially when tuning for higher cylinder pressures or more demanding driving conditions.