Im betting it has copper plugs in it as OE, mopar is famous for being cheap. I cant remember seeing platinum or iridium plugs in any Chrysler product unless some one put them in after the fact. anyway, what difference does it make what plug came from the factory in it, just buy the plugs you like that are correct for it and put them in, don't over think it. as far as the heat that's an across the board thing with mopar also... don't know what to tell you on that