E3 Spark Plugs E3.90R-8: J-Wire Race Spark Plug, Non-Resistor, 14mm/.75", Gasket, Tip Reach Standard, Each - E3 Racing "R" Series spark plugs are fitted with a nickel alloy ground electrode, allowing for excellent heat transfer and an adjustable gap for high-compression engines ...E3 Spark Plugs E3.90R-8: J-Wire Race Spark Plug, Non-Resistor, 14mm/.75", Gasket, Tip Reach Standard, Each - E3 Racing "R" Series spark plugs are fitted with a nickel alloy ground electrode, allowing for excellent heat transfer and an adjustable gap for high-compression engines. They are designed to have a cold heat range, non-resistor, and can be used in a variety of racing applications. Start your engine with E3 spark plugs, select the electrode type and heat range desired.