There does seem to be a lot of confusion about "tune-up" grease. This right up there with "Soylent Green is People!"...but the truth is...Dielectric Grease is Non-conductive. It is intended to help keep the cheap rubber boots on 'merican cars from arcing down the spark plug insulator. I worked (briefly) with a guy that would not believe it even after I took an Ohmmeter and proved it was an insulator. Ah the memories...