what's in spark plug ceramic
Spark plugs use a ceramic insert to isolate the high voltage at the electrode, ensuring that the spark happens at the tip of the electrode and not anywhere else on the plug; this insert does double-duty by helping to burn off deposits.
Nearly all spark plug manufacturers use platinum in one form or another on their long life or performance spark plugs. - On long life spark plugs a thin wafer of platinum is bonded at the firing point to the center electrode (and possibly ground electrode) solely so they donât wear as fast as a traditional plug.