I have the NKG Iridium plug installed. No big improvement, but there was an improvement. I have only had them in for a little over 1700 miles. I just did a valve adjustment and removed the plugs. Both looked great, didn't even bother to clean them, just put them back in.

Tom

Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety. Benjamin Franklin, US author, diplomat, inventor, physicist, politician, & printer (1706 - 1790)