This article? The one that says your plugs should burn off once reaching operating temp! Maybe you should read and understand the WHOLE THING instead of picking out one line to try and justify your problem because the answer is in there.
Exactly. And if you drive at low speed and/ or short trips, then your plug doesnt reach the normal operatin temperature. What happens? The plug turns black. Did you read the whole article? There its clearly been written.
Go to your car, take your finger and put it in exhaust pipe. After that look at it and see it turned black. Yes its carbon. Yes its normal even in engine that is perfectly in good shape.
