Bosch launches new platinum Spark plug. Bosch has announced the launch of a new platinum spark plug to add to its premium spark plug family. Bosch platinum Iridium Ir fusion is the latest spark plug to be launched by Bosch and combines an Iridium and Platinum centre electrode with Bosch's air-gap technology. The spark plug has yttrium-enhanced ground electrodes which Bosch claims provide excellent performance life, with ground electrode durability improvement of up to 87 percent when compared with nickel chromium.