CVT fluid, not ATF
For the longest time, automatic transmission fluids (ATF) are known to be used on not only in automatic transmissions units but also power steering systems. With the introduction of a new automatic transmission system called the continuously variable transmission (CVT), ATF soon after had specifications, each type to be used in cars other than those with small engines. CVT has now began to show up for big engines in major car brands like Toyota, Subaru, Nissan, etc.
But what if Automatic Transmission Fluid (ATF) fluid is added to a new tech CVT transmission or if CVT fluid is added to a conventional automatic transmission? Theoretically, this should damage the transmissions, not right away, but surely in the long run. But these fluids are hard to confuse with. First of all, conventional ATF fluid is red while CVT fluid is green. It is NOT quite unthinkable that this mistake happens given the fact that the Auto Tranny is synonymous to ATF. Even more crucially, most modern cars do not make it easy for consumers to change transmission fluid on their own. Most CVT transmission dipsticks are only for checking fluid levels and needs a special recirculating pump in a service center to change the fluids. There are no D.I.Y plugs for changing fluids. This is because you really should bring the car in for a checkup if the transmission fluid level is low. Almost all higher-end cars come with sealed automatic transmissions.
But when the unthinkable happens and ATF fluid finds its way to a CVT transmission, it's more likely to be done by an ignorant or clueless mechanic more than by the car owner. It is unfortunate that the owner of the car would probably not be able to tell the difference, as there will only be a slight oddity. But there will surely be long term damage in the CVT transmission. Not in days, weeks but after a few months. Why? CVT Fluid is specifically designed for the belt-driven transmissions. CVT fluids contain specific friction modifiers that provide the proper friction needed for the chain or belt to grip and drive the cones. The operation of a CVT transmission is so different from a conventional one that failure to add CVT fluid or a mistake in adding ATF will wear out the cones over time.
The cars with CVT transmission are usually changed with an external pump machine that can only be found in a service center. If a CVT transmission is loaded with ATF without the use of a proper pump, the car will still work for a period of time as it is impossible to drain all the CVT fluid. So when a usual mistake of adding ATF fluid to the CVT transmission happens, the transmission would contain a mixture of CVT and ATF fluids.
There will still be enough friction provided by the remaining CVT fluid for the CVT transmission to work for a while until eventually the whole transmission will fail and will need to be rebuilt. How long the CVT transmission will continue to work is believed to be a function of how much CVT fluid is left in there. You should be able to continue driving the car for longer if the CVT fluid is more than the ATF in the mix, but in both cases there will be permanent damage done to the CVT transmission. Failure is only a matter of time unless perhaps if the problem was detected and corrected early.
ATF fluid, on the other hand, is used to lubricate and actuate a more primitive transmission that basically consists of a hydraulic pump for pressurizing the system, a set of gears, clutch discs and shafting. It is not going to do the job with new tech CVT transmissions that are gearless systems of chain-driven or belt-driven cone roller gears and pulleys.
So know more about your car and check if you have a CVT system. If you do, you already know that ATF and CVT fluids are not the same.
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