The burn ring indicates that hydrocarbons have been burnt. That's typical. Google used spark plugs and you'll see that on many used plugs. What you want to do is check down where the plugs screw in for any oil pooling. If so then you might need a new valve cover gasket set to prevent oil leaking into the spark plug wells.
I would recommend NGK Iridium spark plugs over brands. I've tried several others and NGKs have performed the best on my TSX. Maybe others have had good experience with other brands, I'll let them chime in.
I would recommend NGK Iridium spark plugs over brands. I've tried several others and NGKs have performed the best on my TSX. Maybe others have had good experience with other brands, I'll let them chime in.
