Skip to Content

Is Engine Oil Conductive? (All You Need to Know)

Engine oil plays a vital role in any car’s engine. The oil lubricates the engine and keeps it in good working order. Can engine oil also act as a conductor? In case you are ever unsure as to whether engine oil is conductive or not, here are a few ideas that will help you understand.

Is Engine Oil Conductive?

Engine oil is one of the most conductive liquids available for automobiles. Engine oil is such a good conductor due to its high viscosity. This explains its slow movement and resistance to flow. Make sure you clean the engine and oil cooler thoroughly before changing the engine oil. 

Furthermore, engine oil has a high lubricity index, which means that it is resistant to wear and tear. The right engine oil must also meet your vehicle’s specific requirements, that is why you should always use a high-quality product. 

A good example is low-viscosity oils such as petroleum mineral oil or syn hybrid. It is known that they are highly resistant to heat, but they quickly decompose in the combustion chamber of an engine.

Your car’s oil conducts electricity when you drive it.  When you ask people about the conductivity of metals and fluids, most of them are going to say that Mercury conducts electricity. 

This metal has a much higher electrical conductivity than other metal elements like copper, for example. Among the metals, mercury has one of the highest electrical conductivities of all the metals. 

Unfortunately, most of the metals are not as good at conducting electricity as mercury is. When an electrical current passes through a metal, electrons move randomly instead of following specific paths.

Is engine oil a conductor?

In general, engine oil acts as a conductor of electricity, but this can vary depending on the particular oil and application. The oils that are used for cold-starting are not typically conductors, whereas the oils that are used in high-performance engines are usually.

During the operation of a capacitor, an electric field flows between two plates, separated by an insulating material, called a dielectric. The number of electrons gathered within this region is compared with the amount flowing out. 

Sparks caused by an electric current can cause fuel gasses to enter the small space between two metal plates in a tube capacitor. 

This principle underpins combustion engines. Due to too low a compression ratio, it may not result in complete atomization of air/fuel mixture in its cylinder volume. 

There is a possibility that the cooling system could be contaminated with unburned hydrocarbons. Due to this, there would be higher emissions, fouling, and decreased engine efficiency as a result.

Is engine oil a good insulator of electricity?

Engine oil is not a good insulator of electricity, but it is a good lubricant. Most engine oils contain it as their primary ingredient. Engine oil is not designed to function as electrical insulation, but it does help to reduce friction and heat buildup in engines. 

The engine can therefore be prevented from overheating and fuel consumption can be reduced as a result. 

In addition to the fact that engine oil acts as an insulator, one might expect that some compounds will be exposed and that will harm engine performance. 

It is usually the sludge at the bottom of a bottle of motor or transmission fluid that is the first thing you notice when you crack it open. On the other hand, there have been high-performance oils that offer even better performance than general-purpose butyl-based products.

What is the viscosity, thermal conductivity and heat coefficient of engine oil?

The viscosity, thermal conductivity of engine oil and its heat coefficient are important measurements that help an engine perform better. 

Viscosity, basically refers to the state of engine oil in a specified temperature. Higher viscosity means thicker engine oil and lower viscosity means thinner one. However, thinner engine oil can flow pretty much easier than the thicker one.

On the other hand,  thermal conductivity is a measure of how well an oil conducts heat, while heat coefficient measures how quickly heat is transferred through an oil

The thermal conductivity of high viscosity oil takes more time to heat up, and it will not flow freely. To achieve the same level of performance, an engine will need to work harder.

Alternatively, oils with a low viscosity, thermal conductivity will heat up quickly and give the engine a more responsive feel. For high-performance engines that need to operate at peak performance, this makes sense. 

There are a few theories that can explain the difference. Oils with different molecular structures and sizes will have different viscosity thermal conductivity. Heat capacity measures how well oils resist temperature changes due to friction. 

According to the first theory, high-performance engines should use higher quality oils with better additives. For them to maintain their performance over time without failing degradation from overheating or engine damage caused by excessive wear. 

The second theory states that high-performance engines require oils with low thermal conductivity. The engine operates at its peak performance and avoids stalling or losing power when using them.

What happens when electricity touches engine oil?

The following scenario might occur when electricity touches engine oil – 

Causes spark:

Electric sparks can cause engine oil to ignite when they come in contact with electricity. So, when working with or around engines, you should always wear protective gear, and you shouldn’t touch any part of your body directly.

Oil spills:

Besides electrical currents, an oil spill might also be caused by a faulty electrical device. It can happen if you accidentally receive a shock while working on one of these engines, causing the engine sparks to fly to the surface and spread out through your oils. 

It can happen if you don’t wear protective gear when working on these engines. It is not uncommon for some workers to face these injuries while performing maintenance on their unprotected bodies. In gasoline tanks, we can fix motorcycle batteries or car batteries.

Causes fire:

When electricity gets in contact with oil, it can cause a fire. High visibility safety vests and gas masks should not pose a problem to people who have worked on engines before. Since the above mentioned are likely to ignite an engine and oil. 

You can use this equipment if you have access to them. During do-it-yourself work, it is recommended that you use them constantly even if you are not working.

Battery fail:

When a battery or motor fails suddenly, sparks can be generated from exposed or traveling electrical components or motor oil, thus extending the burn propagation time. 

It has been reported that there have been some similar cases in the past of coffee cups illuminating an engine and causing damage until this particular incident occurred at a garage in Auckland hours after it closed as it was after hours.

What oils are conductive?

Using engine oil in an electric car engine is similar to using oil in any other motor vehicle. Here are some oils that are good conductors of electricity.


Petroleum is a conductive element. Engine oil based on petroleum is often effective. Because of their low viscosity, these synthetic lubricants can help increase power output from idling engines more quickly.

polyethylene oil:

Polyethylene oil is one of the highly conductive oils. As long as the fibers maintain their integrity when this kind of oil contacts a hot surface in the cylinder, it will show that they have electrical conduction properties. 

These characteristics are usually found in engineering oils designed to withstand wear and heat. Diesel engines benefit from using these types of oils as they allow a higher compression ratio without causing detonation or browning of the oil as a result of excessive heat.

hydraulic fluids:

Hydraulic fluid is commonly used for power generation, such as to form hydraulic systems. Transmission lines and oil hose systems can conduct electrical tests if they come in contact with them due to the characteristics of their transmission lines and oil hose systems.

Reversing fluid:

Electrically-powered automobiles do not typically use reversing fluid. Their reversers are capable of working without reversing fluid. The reversers are also conductive.  Many blades make direct contact with oil injectors and seals since they are connected to blades.

Non-conductive fluids will not conduct if they come into contact with other fluids or hot surfaces within a car’s engine or gearbox.

Final Thought

Engine oil is conducive to some degree, but not to a great extent. It can nevertheless function as a ground for electrical currents. The reason is that they have a higher resistance than oil, which means that they can block or reduce the flow of current.