.66 DiamondFIRE Spark Plug

The E3.66 Automotive Spark Plug is a 14mm, 1.000-inch reach plug with a taper seat, designed to fit a wide variety of late-model applications, particularly Hemi engines. Its construction features three legs that secure the DiamondFIRE electrode to the shell, promoting excellent heat transfer and creating more turbulence within the cylinder for improved combustion. Combined with a unique ground electrode and a full-size center electrode, this spark plug is built to provide optimal performance. E3 guarantees optimal performance for a period of five years or 100,000 miles. The plug has a fixed gap that cannot be adjusted, with a resistor type and a 5/8" hex size.