[Brian in Tucson]

Copper plugs are s upposed to provide better spark, but they don't last as long. Iridium are much more expensive, but have much longer life, too. I believe I put in the Nippon Denso iridiums, the engine had previously had Beru, which I think was OEM. I get most of my auto parts at the Rock, I think mine had a rebate. Always had good results with ND, I have ND coil caps in both my cars. And a set of ND O2 sensors in waiting for the Boxster. Coils and sensors are still crazy expensive, tho.