Are There Any Fluids In A Tesla? Here’s What You Need To Know


Electric vehicles have been engineered to replace the internal combustion engine with electric motors. Traditionally, the internal combustion engine has been an engineering feat in many regards, especially when it comes to fluids. Special oils, lubricants, sealants, and coolants are required to keep an engine performing adequately. But an electric car doesn’t need all that, right?

What fluids, if any, does an electric car contain? Surprisingly, there are a few fluids that are contained inside electric vehicles. Some include battery fluid, coolant, windshield washer fluid, etc. These fluids will need to be replaced or checked over time, which does mean some service fees but these fees will be among the very few when it comes to electric cars.

It seems weird that there would be fluids in an electric car considering the lack of an engine, transmission, and typical differentials. However, there are actually a few different types of fluid still present in modern electric cars. This article will break down what fluids might be found in a Tesla, what purpose they serve, and how to go about servicing them. We will break the types of fluids into two groups: Big fluids and Small fluids.

What Is Considered A Big Fluid?

We will call these types of fluids “BIG” fluids because they play a big role in the operation and safety of the vehicle. Changing them or servicing them is also a big job requiring a professional touch. The Big fluids in a Tesla are battery fluid, battery coolant, AC refrigerant, and transmission/gearbox fluid where applicable.

Batteries require a special fluid to function properly. In a lead-acid type battery, the fluid, or acid, contains an electrolyte that reacts with the lead plates in each cell. This chemical reaction generates a positive or negative charge. This polarity gives us a way to harness those charges in order to operate motors and other electronics. 

Tesla built a lot of its earlier vehicles with lead-acid batteries. In order to achieve the high voltage needed to power the vehicle, several cells are connected in series, which multiplies the overall voltage. However, Tesla has since implemented Lithium-Ion batteries, which still use an electrolyte, but in much less quantity compared to a lead-acid battery. Typically, the fluid in either one of these batteries won’t necessarily need to be changed or serviced for a typical driver. 

Along with battery fluid comes battery coolant. This is a system specific to electric vehicles. A specialty coolant, much like what’s found in a regular vehicle, is pumped through the battery pack to maintain battery temperature. The coolant traps the heat which is radiated out of the vehicle. This coolant won’t need to be regularly serviced, only periodically checked for adequate level. There is a place to check it under the maintenance panel under the hood. The owner’s manual will be the best source for what type of coolant to use.

Teslas use a special refrigerant to operate the AC system called HFC 134a. While this can be condensed into a liquid, its function is mostly in a gaseous state. This gas is very bad for the atmosphere and so it should only be serviced by a proper technician. Tesla recommends servicing AC every 4 years.

Finally, the gearbox fluid. Tied to the high-voltage electric motor is a “Drive Unit,” which is essentially a transaxle. This uses gear reductions to achieve proper speeds and harness the torquey electric motor. The gear oil used to lubricate and cool this gearbox will likely not need to be replaced under normal driving conditions. Most likely, there will not be an easy way to check this oil, but it should be done during a full inspection.

What Is Considered a Small Fluid?

Small fluids are the types of fluid that the average Tesla owner might interact with more regularly. While they are still important to the proper operation of the vehicle, these types of fluids require less skill to check and service.

First off, windshield washer fluid. Many Tesla owners on YouTube like to brag about only needing to service the windshield fluid as compared to the dozen or so fluids in a regular old car. And indeed many Tesla owners in the real world will only do so. The low maintenance costs are attractive to many buyers. Refilling the washer fluid is as easy as popping the “hood,” opening the maintenance panel, then filling up the reservoir. A gallon of washer fluid costs less than 4 bucks, so this is truly a cheap, easy job.

Teslas also have hydraulic brake fluid for the brake system. Even though a lot of braking can be done through the regenerative braking system, these vehicles are built with a regular brake system for extra safety. This system uses DOT 3 brake fluid, which is available at any auto parts store. Since the brakes are not getting used much, the fluid likely won’t need to be changed often. However, switching out old fluid is fairly easy to do with a little bit of know-how. Otherwise, a competent Tesla technician can get the job done along with an overall inspection

Warranty vs Out of Pocket

Tesla offers a couple of different warranties on their vehicles. These warranties typically transfer to new owners until the terms are up. According to Tesla’s website, each new vehicle is covered under the New Vehicle warranty, which includes a basic vehicle warranty, a safety restraint warranty, and a warranty covering the drive unit and battery. Each warranty has a specific time and mileage term, but the longest is the drive unit and battery warranty, which lasts 8 miles or 100,000 to 150,000 miles, depending on the model. These warranties cover failed components from manufacturing defects or other issues caused by the design of the component. There are ways to add to a vehicle’s warranty, but it must be done through Tesla and not those sneaky spam callers who claim to be able to do it.

The following is a definition taken from Tesla’s webpage on warranties:

“‘Failure’ means the complete failure or inability of a covered Part or Used Part to perform the function(s) for which it was designed due to defects in material or workmanship of the Part or Used Part manufactured or supplied by Tesla that occur under normal use and is subject to the Warranty Limitations listed below. Failure does not include the gradual loss in operating performance due to normal wear and tear or a cosmetic difference or change in a Part or Used Part.” (Tesla Parts, Body & Paint Repair Limited Warranty).

So, while a warranty will cover a component if it fails due to manufacturing defects within the warranty period, you will not have to pay out of pocket. This would include servicing the batteries and drive unit fluids, brake system fluid, and so on, depending on the case. Otherwise, any repairs or maintenance done outside of the warranty period would be an out-pocket expense. 

Cost of Fluids

When it comes to the costs of these fluid services, there are a few things to consider. First, the frequency of services is really spread out. The yearly overall maintenance costs for new Teslas are next to nothing. However, when that time comes to get some services done, there of course will be some costs. 

To start small, refilling the washer fluid is very inexpensive. A gallon of quality washer fluid is less than $4 and is available at any auto parts store and in many large chain grocery stores, such as Walmart. How much washer fluid is used is depending on location and season, but even having to fill it 2 or 3 times per year will only come out to about $10-$12.

A brake fluid service is a fairly straightforward service. Of course, having a trained and capable technician perform the job is the best way to have it done right. On average, a typical brake fluid flush costs around $100. According to the Tesla service schedule, the brake system should be checked annually and serviced about every 4-5 years. Spreading a $100 service over that many years makes this service very inexpensive.

Most, if not all, other fluids in a Tesla will likely be covered under warranty only because the likeliness of the fluid specifically going bad is quite low. For example, if the battery coolant suddenly is dirty or contaminated, that indicates a significant failure in the battery system. During the battery service or replacement is when the coolant would be replaced. 

Similarly, if the gear oil specifically goes bad, that’s indicative of something very wrong in the Drive Unit. An exception: according to some sources, the 2012-2016 model year Model S’s may require a 5-year fluid replacement. Not much data is available on how much this costs, but a similar procedure on a normal car costs about $100, depending on location and so on. So again, not an expensive maintenance issue. All newer Teslas have a sealed Drive Unit and require no services. 

Conclusion

The low maintenance costs seem all well and good while the vehicle stays within the warranty life. However, it often seems like as soon as the warranty expires is when problems start to show up. An older vehicle will require additional repair costs as components eventually lose longevity. Performing proper maintenance is the best plan to prolong the vehicle’s life span.

While it does seem a bit odd that an electric vehicle would require fluids, Teslas have a few systems requiring special types of fluids. All are crucial to the proper operation of the vehicle, but some aren’t as urgent as others. Overall, the cost of maintaining these fluids is very low and may even be covered under warranty depending on the case. The most common fluid is the windshield washer fluid which is incredibly easy to find and fill.

Recent Posts