Dielectric grease is an everyday component in many cars. But do you know what it does and more importantly, is it necessary for your spark plugs?
In this blog post, we’ll address these queries and more. We’ll examine the role of dielectric grease in engines and help you decide if it’s something that should be kept on hand. Stay tuned!
What is Dielectric Grease

Dielectric grease is a type of lubricant designed to reduce wear and tear on electrical connectors and other electronic equipment. It consists of synthetic oil mixed with an electrically non-conductive material, which helps keep electricity from passing through the grease.
Dielectric grease can be effective in avoiding sparks and corrosion from occurring. Additionally, it ensures electrical connections remain tightly sealed against water intrusion.
Dielectric grease is composed of various materials, but the primary ingredient is silicon dioxide. Other common ingredients may include aluminum oxide, zinc oxide, and titanium dioxide; however, the exact composition varies depending on the manufacturer.
Dielectric grease comes in both aero-sable and non-consumable forms. The former is usually employed for electrical applications, providing a shield between two conductive surfaces. On the other hand, consumable forms may be employed during food preparation or as lubricants.
Is Dielectric Grease Necessary For Spark Plugs?

Dielectric grease is not always necessary for spark plugs, but it can be beneficial. Dielectric grease helps prevent corrosion by creating a barrier between the metal of the plug and moisture in the air, which helps extend their life by avoiding rust and other forms of corrosion.
Another benefit of dielectric grease is that it improves electrical contact. Applying it to a spark plug fills any gaps between metal surfaces, creating an improved connection and better electrical flow.
Dielectric is a nonconductor of direct electric current. That is, it acts as an insulator rather than a conductor and should only be applied to the ceramic part of spark plugs, not their terminal.
Dielectric grease is an insulating compound commonly used to coat electrical connectors. It can be found in everything from car spark plugs and household electronics. Spark plugs use dielectric grease because it helps create a better connection between them and the engines, leading to improved performance and longer spark plug life.
Dielectric grease can help protect against corrosion and improve electrical contact when replacing spark plugs
How To Properly Use Dielectric Grease on Spark Plug Wires
Dielectric grease is an integral part of properly caring for your spark plug wires. Not only does it shield them from moisture and corrosion, but also provides an electrical connection.
Here is a step-by-step guide on how to apply dielectric grease on your spark plug wires.
1. Remove the spark plug boots
You’ll need three tools for this job: a ratchet, an extension, and a spark plug socket. The first step is to locate the spark plug boot at its end. Use your ratchet and extension to remove it with ease.
Be mindful not to damage either the boot or the end of the spark plug when taking it out of the engine. Use a spark plug socket to safely take out the plug from its socket; be sure to insert it firmly so as not to damage it.
2. Apply dielectric grease on a cotton swab
Dielectric grease acts as an insulator, so it should be applied to the inside of a spark plug boot. A cotton swab makes for an easy applicator; just fill your fingertip with small amounts of dielectric grease and rub it onto both sides of the plug boots.
Apply a thin coat using circular motions. Doing so will guarantee that the grease completely covers the inside of the boot and offer optimal protection.
By doing this, the boots will stay off of the ceramic portion of the spark plug and make future removal much simpler.
3. Apply dielectric grease to the ceramic portion of the spark plug
For added protection, you can apply a thin coat of grease to the ceramic portion of a spark plug. Be sure not to get any on the metal terminal. Dielectric grease should never be used on the distributor or coil ends of spark plugs.
Dielectric grease acts as an insulator and will protect the spark plug from corrosion. However, too much dielectric grease on the plug may weaken its spark, leading to misfires. Be sure to wipe away any extra grease before installing your spark plug.
What happens if you use too much dielectric grease on spark plugs?
Dielectric grease should never be overapplied on spark plugs, as too much may cause misfiring and engine damage as well as reduced fuel economy. Be sure to follow the manufacturer’s recommendations when applying dielectric grease; too much may even lead to overheating of the plug which could further wreak havoc.
Dielectric grease is a silicone-based compound used to shield electrical connections from corrosion. It should only be applied sparingly, as too much can lead to issues with spark plugs.
Furthermore, avoid getting dielectric grease on the threads of the spark plug; if this does happen, clean it off before installing in your engine.
Dielectric grease can also be applied to other electrical connections, such as battery terminals and distributor caps. When using dielectric grease on these types of connections, always follow the manufacturer’s instructions.
What happens if I don’t use dielectric grease on spark plugs?
Without dielectric grease on your spark plugs, they can corrode over time and lead to engine misfires. Not only does this increase engine damage but it can also decrease fuel economy; so make sure that you use dielectric grease on all spark plugs in order to maintain their optimal condition.