Features and BenefitsDual platinum tip for improved resistance to spark erosion and corrosive combustion chamber environment. A platinum center electrode and a platinum pad lower the ignition demand voltage. One-piece integral suppressor seal helps reduce radio frequency interference, meters spark plug energy to help provide long electrode life and seals against compression leakage. Designed with a corrosion-resistant shell. Spark gap remains virtually unchanged during the life of the plug. An ideal plug for vehicles requiring platinum performance or older vehicles calling for conventional plugs, ACDelco's Professional Platinum Spark Plugs can give up to 100,000 miles* of service in some applications.*Maintenance needs vary with different uses and conditions. See Owner's Manual for more information.Function & Signs of WearFind out more about the ACDelco Professional Platinum Spark Plug and how it fits into the Starting and Charging System with the product facts below.FUNCTION: Uses a high-voltage spark from the ignition coil to ignite the air/fuel mixture inside the engine's cylindersSIGNS OF WEAR: Poor starting characteristics, decreased fuel economy, sluggish engine performance, excessive foiling or deposits on plugWhat It DoesThe Starting and Charging System starts the engine, maintains the battery's charge and provides power to the electrical accessories while the engine is running. Designed to last up to 100,000 miles.