The Best Transmission Fluids in 2020

Maintaining your vehicle isn’t all that difficult. It can be as simple as changing the oil that powers your vehicle at recommended intervals. This will allow your car to run for many miles without any issues.

However, if you do the opposite and forget to change the oil and oil filter at the recommended intervals, your car will start to develop problems and over time this will lead to the reduced useful life of your vehicle. You wouldn’t want that, would you? Of course you wouldn’t!

To keep your car in good health, not only do you need to change its oil and oil filter regularly, but you also need to change the transmission fluid in your vehicle to ensure its longevity. Here, I will discuss the role of transmission fluid in a car, how often it needs to be changed, and the best transmission fluids available on the market in 2020.

The Role of Transmission Fluid in Your Vehicle

Transmission fluid is a key component for the proper functioning of your car. Especially in contemporary automatic transmissions, it serves as a hydraulic fluid and lubricant. What does this help accomplish in your car? It makes it easier for energy to transfer between the mobile parts of the transmission.

As the propeller of the torque converter driven by the motor spins to drive the piston, the transmission fluid mitigates the force, which consumes some of the movement and uniformly passes it onto the axles.

All of the transmission’s metallic components cannot be rubbing against each other if it is to function appropriately. The transmission fluid serves as a lube between the mechanical components of the transmission to allow its smooth functioning without damaging the gears. If this wasn’t the case, loose metallic parts and the dust in between gear would ruin your transmission.

In the past, whale oil was the primary transmission fluid used in vehicles. However, this fluid did not last for too long and there were two major reasons behind it. The first was that the whale oil used as transmission fluid would easily break down when putting under pressure, such as being exposed to high heat.

Secondly, the fact that the oil was extracted from dead whales—that may or may not have been killed for this very purpose—alerted environmental and wildlife protection agencies. The activism from the protestors left automakers with no option but to look to for synthetic substitutes, just like they were forced into formulating synthetic engine oil.

Over the next few years and after a lot of experimentation, several automakers were able to come up with various types of transmission fluids, each one formulated for a specific type of car. These synthetic transmission fluids were improved over time and this resulted in the modern transmission oils that we have today. The owner’s manual of most vehicles today explicitly state’s the type of transmission fluid the vehicle needs. So you would do well to check your car’s owner’s manual for the recommended transmission fluid.

The Right Frequency of Changing Transmission Fluid

Now that you know the role transmission fluids play in your car and the types of transmission available today, it is time you found out about the frequency with which you need to change your vehicle’s transmission fluid.

The right frequency of changing transmission fluid will vary from one vehicle to another. However, the recommended frequency of transmission fluid change stated in most car owner’s manual is every thirty thousand miles. However, some transmission fluids and vehicles afford you the luxury of going over by two or three times. Yes, that much!

The right frequency of changing transmission fluid is a hotly debated topic, with different experts having a different take on it. Some recommend changing the transmission fluid in your car every thirty thousand miles, while others say that your car can run for much longer before you need to change the fluid.

Since it’s better to “err on the side of caution”, I would recommend that you follow the conservatives and change your transmission fluid every thirty thousand miles. This should be your market for all future transmission fluid change.

However, at the same time, I would recommend that you check your transmission fluid right away after you start to experience any issues in your transmission. Bad transmission oil is what could be causing the problem. How do you know it is your car’s transmission fluid at fault? You should look for a transmission fluid that is darker than it should be.

Generally, fresh transmission oil would be green or red in color. If you notice a darker shade of any of these colors in your transmission fluid, it could be a sign that your transmission oil is overheated or filled with contaminants.  What you need to do next is as obvious as it can get—you should change your transmission fluid right away. But, which transmission fluid should you be using in your car? I provide you with some options in the next section that lists the best transmission fluids in 2020.

The 4 Transmission Oils to Get in 2020

Using the right synthetic engine oil is crucial to maintain your car properly. Changing your car’s transmission fluid at appropriate intervals is also important for the maintenance of your car for longevity. While you can go to a car service center to get your transmission fluid changed, performing the activity yourself can be a lot less expensive.

However, before you undertake this responsibility, you must find out the best transmission oil for your car in 2020. This is easier said than done, mainly because there are a plethora of transmission fluids available on the market today. Many of them will be exactly or close to the type of transmission oil recommended in your owner’s manual.

The good news is that you do not need to go through all the hassle of researching and then shortlisting the most appropriate transmission fluids for your car. This is because I have already done all the hard work on your behalf. My list of the best transmission fluids in 2020 includes transmission oils that will perform efficiently in most cars today. So, you can expect to find at least one transmission fluid on my list that works well in your car.

1. Red Line Transmission Fluid

This transmission fluid contains a low-sulfur composition that makes it less slick and more adaptable with brass synchronizers. The Red Line fluid holds steady when used for efficiency applications, even at extremely high temperatures. It meets gear and motor oil viscosity specifications. Additionally, you can buy a lighter viscosity version too.

One of the best things about the red line transmission fluid is its versatility. By using the transmission oil, you will ensure faster transmission changes, improved gear safety, and an elevated friction coefficient. Additionally, it will perform equally well on high and low-mileage cars. Whether you own a Nissan, a Mazda, a Volkswagen, or a Toyota, you can expect the red line fluid to work efficiently in your car.

What is the outcome of this? You get a transmission with superior performance and smoother operation. Compared to cheaper fluids that break down easily at higher temperatures, the red line fluid has greater resistance to external factors. This allows it to ensure the optimal performance of your transmission at even high temperatures. Additionally, the fluid ensures a smoother operation by allowing easy movement and shifting of gears.


  • Meet viscosity specifications of motor and gear oils
  • Not very slippery
  • Adaptable with brass synchronizers
  • Performs well at high temperatures
  • A lighter viscosity version is available


  • Is more expensive than most of the other transmission fluids available on the market

2. Royal Purple Transmission Fluid

The next transmission fluid on my list is the automatic transmission fluid from Royal Purple. Why do I recommend this transmission oil? I recommend this fluid because it is extremely efficient, has great oxidation stability, and provides great compatibility.

The Royal Purple transmission fluid should be your pick if you’re looking for high-performance transmission oil. This is because this transmission oil prevents wear and tear through its superior film strength, is compatible with other oils used in your car, and lets your vehicle run longer before a transmission fluid change is needed.

Synthetic transmission oil, the Royal Purple fluid, ensures optimal transmission function at high temperatures thanks to its superior film strength. This, along with the wear and tear protection provided by it, allows the fluid’s film to ensure the longevity of your car’s transmission.

Like the synthetic engine oil from the same company, The Royal Purple transmission oil is specifically formulated to provide cooling and protection. It is also designed for compatibility with other fluids in the car and for improved oxidation stability. The latter helps to ensure the smooth operation of your car.


  • Ensures your car’s longevity
  • High film strength for cooling and wear and tear protection
  • Superb compatibility with other fluids


  • Some car owners may not experience all of the benefits of the transmission fluid stated above

3. Castrol ATF

This transmission fluid is in my list of recommending transmission oils because its consumer tested for smooth shifting.  This is made possible by the fluid’s superior friction durability. In addition to this, the Castrol transmission fluid ensures superior transmission performance by meeting the specifications of Mercon, and Dexron—II, IIE, III, and III H.

For owners of cars that require Mercon, the Castrol transmission oil is recommended for use in power steering.  This means that the Castrol fluid can be the perfect choice for owners of cars requiring Mercon who want to use the same product to top off their powering steering and transmission.

However, before you use the Castrol transmission fluid in your car, check your car’s owner’s’ manual to be sure that this transmission oil matches the type of transmission fluid recommended for your vehicle. This will serve your well in the long term.


  • Can be used to top-off both your car’s power steering and transmission
  • Superior friction durability
  • Consumer tested for smooth shifting


  • May not work efficiently in some vehicles

4. Mobil Transmission Fluid

The fourth and final transmission fluid on my list is the Mobil transmission fluid. I recommend this transmission oil because it is proven to increase the efficiency of a car’s transmission. Additionally, the Mobil fluid extends the transmission’s longevity as it is premium quality transmission oil that does not break down very easily.

The transmission oil from Mobil will ensure great transmission performance in even the worst of conditions by maintaining the transmission’s hygiene. This transmission oil performs far better than most automatic transmission fluids on the market today because it is extremely resistant to breakdown and oil deposits. It performs exceptionally well at high temperatures thanks to its high viscosity stability that prevents thermal breakdown.

Also, since the Mobil transmission fluid does not break down easily, it allows smoother operation of the transmission. Additionally, it flows superbly at extremely cold temperatures, even those as low as over negative 50 Celsius. Lastly, the transmission of oil from Mobil is extremely versatile and can work optimally on many different types of vehicles.


  • Fast and reliable vehicle lubrication
  • Increased efficiency and longevity of your car
  • Excellent protection against wear and tear
  • It ensures the hygiene of your transmission
  • Works well in the worst of conditions


  • Cars needing Dexron IV are not recommended to use the transmission fluid from Mobil

Final Word

There are many transmission fluids available on the market today. However, not all of them will be right for your vehicle in terms of both quality and specifications. Therefore, it is critical that you know about the type of transmission oil recommended in your car’s owner’s manual.

Once you have this information, you need to find a transmission oil that fits the recommendation in the owner’s manual. Or you could simply find an appropriate transmission fluid for your vehicle by going through the list of the best transmission fluids in 2020 detailed above. You will surely find at least one transmission oil that meets your criteria.

News Reporter