Bosch Super Plus Spark Plugs deliver quality performance based on technology that is proven on racetracks around the world in the most sophisticated racing engines. Testing has confirmed the durability of yttrium-enhanced center electrodes which offer superior reliability and 50 percent longer performance life. Super Plus also features a tapered, v-profile nickel chromium ground electrode for improved starting in cold weather and increased fuel ignitability, nickel-plated rolled threads for complete anti-seize and corrosion protection, a metal glass fused resistor for maximum interference suppression, and angular, five-ribbed insulator design to prevent misfires due to current leakage.