i have the ngk iridiums in my car i didnt notice shit performance wise. i just didnt want to change copper plugs every so often and i tried bosch platinum+4 and they dont do shit either. just stick with copper if you dont mind changing them often, but im lazy so i got the iridiums because they supposedly perform like a copper plug but with the durability of a platinum plug, but like i said, same shit, they just last longer. i got them for $20 along with the ngk blue sp wire for $35. ebay is the shit!