How often should I change transmission fluid of my 2020 Prius AWD XLE?

I would assume 'special' conditions applied to me. One document unearthed suggests the engineers wanted replacement every 150,000 kms, about 100,000 miles.

 

I do not read Japanese,so I never read the document myself.

 

I would counter, solely on the appearance of drained fluid, that a static interval is not appropriate. In my experience that fluid was darkest at the first drain, around 15k kms, and subsequent, longer interval fluid was surprisingly clean. Accordingly:

first change at 10k miles or 1 year.
Second change at 60k miles or 6 years.
Done.

 

Mendel is correct.

From a Mechanical Engineering point of view, all interacting new components will experience "wear" to allow for "better fitting/inter-operation" of the components.
Basically, parts "wear to match each other".

So, you want that "early" fluid change, after the parts "have worn together".
That gets rid of all of the particles/etc.

Then, you want regular, easy to remember, fluid change intervals.
Some people have/use schedulers/etc.
Most people do not. Hence, why I say "easy to remember" fluid change intervals.
So, I suggest, ~10K miles.
Then, 50K miles, 100K miles, 150K miles, etc.


For a regular non Plug-in Prius, the tranny "hybrid MG1/MG2 drive" gets lubricated by a sophisticated "splash" lubrication system.
For the Plug-in Prius tranny, Toyota added an external battery-operated tranny oil pump, because of the extra load on the hybrid motors.

So, in either case, you want clean fresh good tranny fluid in your tranny.

Code:

More on difference between the Plug-in and and regular Prius tranny:

Start at: ~14min
How do Toyota Plugin Hybrids work? Completely different than Hybrids?
The Car Care Nut
Jun 12, 2021
https://youtu.be/Scy9UCX-0vc?t=873

Start at ~39min:
https://youtu.be/-dHeRJdrnI8?t=2397
2016 - 2022 Prius, Prius Prime Transaxle - P610 Deep Dive (P710, P810 Similar)
May 30, 2017
WeberAuto

Good Luck!

 

Over $100 is a rip.

 

Check out the “Car Care Nut” on YouTube FWIW. He addresses this specific question and actually is qualified to answer it.

 

Check out these interesting YouTube videos.

I have a 2012 Prius v. I first changed the transaxle fruid in 2014 at 13.5 k miles as a precaution to remove the assembly lub and "flash" dross from early wear-in of all mechanical assemblies. I installed a magnetic drain plug, since Toyota no longer supplied them with the 2010 Gen 3 model year.

Yesterday, at 27.4k miles and 10 years, while swapping a new magnetic drain plug for a new one, I drew off 100ml of fluid into a clean pan.

The magnet was coated with steel bits worn off the gears.

The fluid was a dull red like new.

Accordingly, I filtered the fluid and re-injected it back into the fill port.

 

FWIW, I’d follow his advice.

 

Didn't want to crack open the four quarts that I had to do a full fluid change.. The condition of the removed fluid was just fine.

I'll probably replace it all when the car reaches 50k.

 

I just changed our 2019 at 61K miles. Frankly it looked way better than I expected given how dark our 2009 Prius fluid was when I did it at 60K for the first time.

New fluid left. Old fluid right.

 

On my hybrids, I go with every 6-years or 100,000 miles (e-CVT trannies). On my non-hybrids, they get changed out every 5-years, or 100,000 miles. I can't believe my Yota dealership charges $310 for a transmission service on my Hybrid (I called them). It's a simple drain and fill like a rear differential....actually easier than doing an oil change.

 

Any one who goes by appearance for automotive fluids…..let’s just say……?
Well I guess the most polite thing to say is???????????! So, do you want your vehicle to last well past the manufactures warranty, or do you want something else? Perhaps the best question is do you want to buy someone’s used vehicle that “seems” conservative or someone who went by anything else? I personally don’t care what my transmission fluid or oil or coolant or brake fluid LOOKS LIKE!!!! I want it to perform it’s intended function, not please my eyesight. But WDIK? I’m just an old fart? Ignore the education level