Denso, in a move to improve the longevity and performance of the spark plug over even the platinum electrode type, has introduced its Iridium Spark Plug. The plug, which actually uses a nickel-iridium-platinum alloy, is said to be a substantial improvement. Iridium, six times harder and eight times stronger than platinum, offers improved wear characteristics and the ability to shrink the surface area of the center electrode tip. The less metal on the tip, the lower the spark voltage requirements. Accordingly, the Iridium Spark Plug’s electrode measures 0.4 mm in diameter, the smallest center electrode made according to the company. Contact: Denso Sales California, 3900 Via Oro Ave., Long Beach CA 90810.