I checked on the internet the Toyota bulletins on changing the oil in a 2010 Prius and it says it should last the live of the car unless there are leaks or repairs to it...... so why do people say around 100K on this forum.. I'm just asking as I bought the oil but finding out that I don't need to do the CVT liquid change... thank you in advance.
The oil you bought was ATF WS, I hope? The CVT in a Prius is not mechanically similar to CVTs in non-hybrid cars.
What's the miles on it? My 2 cents: do it at least once, around the one year or 10K miles is good. Then you can let it go quite some time,/miles, say till 10 years or 100K miles. Toyota says nothing about it, for maybe a couple of reasons. 1. It will survive a long time, no arguing that. 2. It simplifies maintenance requirements. There's a link in my signature about transaxle fluid change.
In what way do you think it is not a CVT? It has a shaft where engine power comes in. It has a differential delivering output to the wheels. It can deliver power from one speed,torque at the input to a different speed,torque at the output, and the ratio between them is continuously variable, not restricted to certain steps the way it is in non-CVTs. Any device that does the above is a continuously-variable transmission, a CVT. We get some of this "it's not a CVT" confusion periodically because there are different ways other CVTs have been built (such as with cones, belts, discs, or the like). #2 mentioned that. But whether something is a CVT or not isn't determined by how it is built—only by what it does. Now, where the "how it is built" can matter is in the choice of oil. Some of those other ways to build a CVT call for a special kind of oil. The CVT in the Prius, however, uses ordinary Toyota ATF WS.
Lifetime fluid is marketing. Lifetime the automaker wants or lifetime the owner wants? Different perspectives sometimes. The fluid is used to lubricate gears and is still subject to things like shearing and oxidation. If you like your car, and plan on keeping it, a drain and fill is easy and doesn't break the bank.
To the auto manufacturers, it is apparent that it is their warranty period on the vehicle. BMW until recently recommended 15k oil changes as a marketing tool.
This is an easy one. It is because the Internet if full of self appointed experts who know more about any device than the Engineers who designed and built it. Even though those real experts likely have a combined training and experience into the hundreds of years.......or thousands maybe.
And work for companies that cost engineer things and want you to buy another one of their products. Absolutely no compromise being made there.
"Lifetime" means for the lifetime of the warranty..... Once the (emissions) warranty is over, you're on your own. It was never meant to last forever. So what is the "lifetime" of the transmission????