Accel 426S Silver Tip Racing Spark Plug - Pack of 4 Accel Silver Tip Racing Spark Plugs offer better ignitability Silver Tip spark plugs utilize Silver the best electrical conductor Allows for a wider heat range and is extremely resistant to fouling Silver center electrode has low ignition voltage requirements and allows easier starting Silver is highly fuel compatible and can be used easily with LPG E85 Methanol Ethanol Injection high compression and high RPM engines