(Updated on October 6, 2022)
Transmission fluid is not something that you need to change as often as your engine oil. Even though they are both lubricants, transmission fluid can last for tens of thousands of miles before it needs to be replaced.
The question is, how many miles exactly do you need to travel before you should change your transmission fluid?
The answer varies depending on the make and model of your vehicle. The manufacturer of every vehicle typically sets their own requirement for when the best time is to change your transmission fluid. You can easily check your owner’s manual to find the proper number of miles for your particular vehicle.
But, there is a general range of miles you can drive between transmission fluid changes, which we’ll go over below. Please note that the fluid in automatic transmission vehicles will not need to be changed as often as the fluid in manual transmission vehicles.
But regardless of which type of transmission you have, you should always try to purchase a good quality transmission fluid because it will literally preserve the life of your transmission as much as possible. Since you won’t be changing the fluid that often, it is worth investing in a quality fluid even though it may cost a bit more.
How Often to Change Automatic Transmission Fluid
The common recommendation from automatic transmission car manufacturers is that you change the transmission fluid at least every 150,000 miles, but preferably after 100,000 miles.
However, your local auto technician or mechanic might tell you that 100,000 miles are still too long to wait. They’ll try to convince you to change your automatic transmission fluid every 40,000 to 60,000 miles instead.
Like motor oil, you can estimate the best time to change your transmission fluid based on the type of driving that you normally do. For instance, if you regularly drive an automatic transmission car around town where there is frequent stop-and-go traffic, then your transmission will generate more heat. As a result, your transmission fluid will deteriorate faster.
But if you normally drive on the highway at a fairly consistent speed without major elevation changes, then your fluid may last much longer before it degrades to the point of needing replacement.
How Often to Change Manual Transmission Fluid
The fluid of manual transmissions has a shorter lifespan. The typical manufacturer of a manual vehicle will tell you to change your fluid at around 30,000 to 60,000 miles. Of course, every make and model will likely have a different recommendation, but one that is within this range of miles.
In some cases, whether a lot of stop-and-go commutes, weekend autocrossing, track use, or simply “spirited” driving, you’re putting much more stress on your manual transmission. This may require the fluid to be changed every 15,000 miles instead. It is not common to have to change the fluid this quickly unless your specific driving habits demand it.
The problem with short distance driving with manual transmissions is that the gears frequently need to be changed. Every time you change these gears, it puts more stress on the transmission. The fluid deteriorates more quickly as it endures this stress.
If you are new to driving a stickshift, then you will stress out the gears even more as you learn how to properly shift. When you make mistakes in shifting gears, this wears down the fluid more too.
Checking the Fluid
When you check the transmission fluid prior to changing it, make sure the engine is turned on. If you find that your transmission fluid level is lower than it should be, then you first need to make sure there are no leaks in the system. Once you can confirm that, top off the transmission fluid right away with an adequate level of new fluid.
Lastly, you can easily tell if the existing transmission fluid is bad because it will look rather brownish and may even have a bad burning odor to it. Healthy transmission fluid has a red color and no strange smells.