Silverstone spark plugs are especially designed for the unique demands of modern high-performance engines. Silver is the best electrical and thermal conductor of all metals, which makes it the ultimate material for a spark plug's center electrode. The large diameter silver center electrode of Silverstone spark plugs increases spark carrying ability and spark power by as much as 137%. Silver is extremely resistant to erosion, guaranteeing a virtually unchanged electrode gap for the life of the spark plug. Silverstone spark plugs are designed without a suppressor resistor, perfect for performance enthusiasts who demand the most from their engines. For racing or dependability and efficiency for everyday use, Silverstone spark plugs deliver the most powerful spark.