Dielectric grease is often used to seal the connection between spark plugs and spark plug wires. The grease does not conduct electricity, so it shouldnt be applied directly to the mating surfaces (pins and sockets) of an electrical connection.

Additionally, does Vaseline work as dielectric grease? Vaseline can work as a substitute for dielectric grease, the big differences are that it can degrade rubber and plastics over time, and its combustible - but Ive used it in the past on car bulbs, wiring and battery terminals and it hasnt been a problem yet.

In respect to this, what grease do you use on spark plugs?

A common use of dielectric grease is in high-voltage connections associated with gasoline engine spark plugs. The grease is applied to the rubber boot of the plug wire. This helps the rubber boot slide onto the ceramic insulator of the plug.

What happens if you dont use dielectric grease?

Chances are, without the dielectric grease, you will destroy the wire if you have to take one off the plug. The boot will be infused to the plug. Thats why you should use anti seize on bolts so they dont break off due to aluminum oxidation.