Your engine needs a true performance spark plug particularly if you have a high performance application that is turbo-charged, supercharged or nitrous-enhanced. The new Denso Iridium alloy, with an extremely high melting point, is used to create the world's smallest center electrode allowing the voltage requirements to be significantly reduced, and greatly improving ignition performance. The tip of the ground electrode has been cut to form a taper. This greatly improves firing performance by reducing quenching. A U-Groove has been cut inside the ground electrode to maintain the large volume of space required to form the nucleus of a flame. Denso perfected the laser Welding Process, which provides a 360 degree seal so reliable the electrode resists wear even in the harshest conditions.