2.6 turbo motor. Plugs gapped to .39. Brand new NGK's. Every time I'd wind it up past 4500, it would misfire like crazy and kill the power and boost. Finally found a post somewhere that said that wide stock gaps have the spark blown out by the turbulence in a forced induction motor. Closed the gap to .32, and the misfire went away, and never came back.

better one. Had a good running 2.6T motor with about 6000 on the plugs, so I pulled them for a new set. Motor had the smoothest idle I ever had on a 2.6, and pulled like a bandit at wot, and cruised like silk. The #1 plug had no center electrode or ceramic at all showing, broken off almost half an inch down inside the threads. Nothing in the cylinder (and no scars) showing with a borescope. No dings on the turbo exhaust wheel. No spark plug guts lying in the cat. inlet. And I have no idea how it was firing the cylinder. I could get no visible sparks from it out of the motor with wire attached and shell grounded. 'splain that one...