What fluids do EVs need?

EV fluids-min

Driving an EV lets you banish engine oil and combustion fuels, but you can never escape fluids entirely.

Electric vehicles are fundamentally different from those with internal combustion engines. The main reason is the power source – an EV’s motor is powered by electrical energy taken from a battery, whilst ICE engines harness energy from fuel to propel the vehicle.

Fluids are utilised in vehicles of all kinds to ensure smooth running and energy efficiency. ICE engines require oil to lubricate many moving components, whilst EVs don’t require this because the motor is simply powered by the battery.

It’s suggested that EVs can use 300% less fluid over their lifetime, which is significantly better for the environment. However, EVs do still require several fluids to run effectively and efficiently.

Find out more below.


Coolant is required to maintain the temperature of battery cells and other components such as the motor because significant amounts of heat are generated whilst in operation.

Overheating can reduce the efficiency of the vehicle and increase the chances of malfunctions in EV components. It can even lead to fires breaking out in the car. As such, optimising the cooling process with cooling fluid and air is critical to ensure safety and efficiency.

However, it is crucial to know that battery coolant does not need to be replaced under most circumstances, no matter how far you drive. It exists in a contained system, designed to last at least as long as your battery packk.

Brake fluid

Despite the innovations in regenerative braking, EVs still require brake fluid to help the vehicle come to a stop. This works the same as in ICE vehicles, although the brakes are likely to get less use on an EV if there is regenerative braking installed.

Related: How EV batteries are improving.

Regenerative braking slows down the vehicle through kinetic energy that also recharges the battery to make the whole system more energy efficient.


Whilst an EV doesn’t need engine oil, various kinds of greases are still required to lubricate other moving parts.

Greases are semi-solid lubricants that help to reduce friction between meeting surfaces in systems such as the powertrain, whilst they can also be useful in reducing noise and increasing energy efficiency throughout the vehicle.

Transmission fluid

Another fundamental fluid that EVs need to operate effectively is transmission fluid, which is best described as a lubricant to smooth the transition between drive and reverse. The fluid is typically a synthetic oil that helps to lubricate and cool the transmission system.

This aspect of an electric vehicle is crucial to ensure the efficient transfer of power from the transmission to the electric motor to the wheels, and through the rest of the drivetrain.

However, transmission fluid is not a serviceable component in most electric vehicles – it exists within a contained transmission for lubrication. So, no top ups.

Windscreen washer fluid

Of course, a driver of any vehicle needs to see out of the windscreen. Therefore, windscreen wash is still needed in EVs to clean the surface in the event of dirt, dust and grit obstructing the driver’s view.

While you can use plain old water for windscreen wash, a 70/30 mixture of water and white vinegar, or dedicated screen wash, is a better option to clear dirt and grime.

James Lewis is our resident electrical head. He drives an MG ZS EV (2018, which he loves) and plans to get the new one soon. James is much more excited by the lower end of the EV market and is looking forward to the Ora Cat.