Accel HP Spark Plugs were designed with the help of Copper core which is a better conductor than Platinum and Iridium, which deliver a stronger spark especially in high-performance applications where high combustion pressures are present. Also Copper is much better at dissipating heat than other materials which lessen the chance of a misfire. ACCEL HP Spark Plugs have custom gapping which allows you to open the gap exposing a larger flame kernel or close it if needed for high boost applications. All ACCEL HP Spark Plugs have machine-rolled threads allowing for a more precise thread engagement and torque retention.