Electric vehicles are known to require less routine maintenance compared to internal combustion vehicles. With electric vehicles, you can say goodbye to regular engine oil changes, but what about the differential oil? Do electric vehicles even have differentials and require oil changes?
Let’s dive into these questions and find the answers!
Do electric vehicles have differentials?
Electric vehicles that feature single or dual motor configurations, such as the Tesla Model 3, are equipped with differentials. These types of electric vehicles use differentials for the same reasons internal combustion vehicles do. When torque is sent to a single axle, either through an electric motor or an internal combustion engine, it must be distributed so that the inner and outer wheels are not locked to turn at the same speed . This is where differentials come in: they allow the two wheels to turn independently of each other.
Differentials are essential to allow the vehicle to turn effectively and maneuver safely in everyday driving situations. In Tesla’s case, the electric motor is connected to a single-speed transmission, which connects the electric motor to an open differential. This differential, which is part of the drive unit together with the reduction gears, needs lubrication. Without it, you’d have metal parts rubbing against other metal parts, with the increased friction causing accelerated wear and ultimately damaging the drive train.
Therefore, certain electric vehicles have differentials that require a specific type of oil to keep everything running properly. Oil is also used to cool certain vehicle components (including the engine itself in some cases), making its way to an oil cooler where the oil and coolant interact to reduce the temperature of the components.
Need to change the differential fluid in an electric vehicle?
Need to change the differential fluid in your EV? Well, that depends on the manufacturer. Tesla makes no official recommendations or suggested service intervals for changing the differential fluid. Maintaining your electric vehicle can be a complicated matter, but you can definitely service your Tesla’s drive unit (where the differential is located) with new lube if you need it (it’s equipped with fill and drain plugs) .
What you would consider differential oil in a traditional car would be more appropriately called a drive unit lubricant in Tesla’s case because the oil lubricates the transmission as well as the differential. Some Teslas, like the Model 3, even have an oil filter that looks a lot like a conventional cylinder engine oil filter, making maintaining the drive unit fluid relatively simple .
There are videos online of mechanics changing the drive unit fluid in Teslas, and the process is relatively simple. The funny thing is that people choose to do this even though Tesla’s service guidelines don’t mention it. Perhaps the manufacturer does not believe that this fluid is under enough stress to warrant frequent maintenance; the most important thing should be to follow the car manufacturer’s recommendations for routine maintenance.
If your vehicle is under warranty and it is determined that the oil needs to be changed, your vehicle will be serviced under warranty by service center experts. Once out of warranty, you can choose to do it yourself or take it to an electric vehicle specialist garage if necessary.
How do you change the differential fluid in an EV?
If your EV’s drive unit fluid is serviceable, you will find the proper fill and drain plugs, and the procedure should be similar to the differential oil in a traditional vehicle. This means that you will need to drain the old fluid using the drain plug and then refill it according to the manufacturer’s specifications, using the specific type of fluid recommended in the vehicle’s service manual.
Always make sure the filler cap can be unscrewed before attempting to drain the oil; you don’t want to drain your vehicle’s drive unit oil without being sure you can refill it. Some vehicles have power units that are sealed for life, with no accessible drain points.
If the service also requires an oil filter, you should purchase the correct oil filter and change the old one at any point in the procedure recommended by your EV manufacturer.
We cannot stress this enough: each manufacturer’s maintenance recommendations are different, so you should consult your owner’s manual before proceeding with any work.
Electric vehicle maintenance is a learning experience
The type of maintenance required for electric vehicles, such as replacing inverters and battery cells (among other electric vehicle-specific components), will likely be different than what owners have previously experienced with their traditional vehicles. Even fluid service intervals may vary due to the reduced stress on these fluids due to electric vehicles producing less waste heat.
With electric vehicles, the most important type of maintenance is to take good care of the battery, as this is one of the most crucial components of your electric vehicle and by far the most expensive to replace.
