In the first place, platinum is used as an inert and durable tip material in = those high quality plugs that carry that designation, not only Bosch does it = but other brands have now picked up on it. The copper mentioned in = spark plugs is used as a core conductor, and it is a very good one. To = compare copper core plugs with platinum tipped ones is of no = value. Maybe the platinum tipped one has a copper core as well. NGK = pioneered the copper core, others have now followed suit. Bosch pioneered = the platinum tipped plug, and the others have followed suit as well. = This so called engineering explanation that must be written in some sort = of prose so very obviously lacks merit that it is = razzel-dazzel in it's purest form. And to say the others are pulling our leg in = their advertising because they claim platinum outlasts iron is = crazy. Who would argue that iron is as durable as platinum? Well I suppose = the guy that has to razzel-dazzel his = explanations. Platinum plugs last longer, they run cleaner, and the perform = better overall because of these reasons.