my mustang runs tons better with autolite coppers, i tried platinum and iridium and they just burned out, i actually had issues melting the electrode to the ground, i saved a couple just because no one believes me when i say i melted an $8 spark plug. my mark had platinums in it when i got it, and they were shot, i put iridiums just to try them out, i only did it because they suck to do, and iridiums are supposed to last longer. i can do my stang in about 15 minutes, the mark took me about 45. if i get a misfire and it's my plugs causing it then obviously i'll go back to copper. my bro's focus runs better with iridium, my old stang ran better with platinum, my old f150 got copper but i also never tried another plug in that thing, everyone i know with a crown vic uses copper, they all said they ran worse with anything else, so ford's might run better with coppers, but the world may never know.
