I've owned my car for four years (third owner) and never touched the plugs. Are these considered a maintenance item which should be changed periodically or should I just leave well enough alone? I only use the car in the warmer weather. The most I put on the car would be 1500 miles/year and it's probably less than that. The car is running fine (maybe a little rough at idle). I pulled a plug and from what I can tell the plug looks ok. The wires look pretty clean and new. I did put an electronic ignition in the car when I got it.The plugs currently in the car are Champion RJ12YC.. Should I change the plugs? What would you suggest I use? Any benefit to using a higher-end plug such as NGK Iridium?Thanks for the advice.Tom1968 Crown convert1960 NYer coupe