The Autolite 5144 Copper Resistor Spark Plug is the perfect choice for your engine. Autolite® Copper spark plugs feature a one-piece terminal stud that provides a reliable high voltage electrical connection and a high alumina multi-rib insulator to help prevent flash-over and misfires. The heat-fused glass composite resistor center seal provides high performance EMI noise suppression and a 100 percent leak-proof seal, while the solid copper core center electrode provides optimal thermal and electrical conductivity for better performance in all driving conditions. For added durability, Autolite spark plugs feature a high nickel alloy side electrode that resists electrical and chemical wear. Backed by a 2 year limited warranty, Autolite's Copper spark plugs deliver quick starts, good fuel economy and smooth acceleration. Upgrade your engine today with Autolite 5144 Copper Resistor Spark Plugs.