Regarding spark plugs for your well loved red blocks, what is the advantage (if any) of using irridium over platinum or platinum over the standard fare that usually goes in the cars? I had read that an irridium plug will not require the same voltage to fire and will last longer than a platinum plug and that a platinum plug lasts longer than a standard one. Is this true and if so, how much longer? I would like to see if getting irridium plugs will allow me to get a good number of miles on the car without worrying about having to replace them for a while. I usually replace them every fifteen thousand miles, but since she gets driven quite a bit when I am around, fifteen k crops up often.