"Lifetime fluid" trans

I've been thinking about this "lifetime" fluid lately. Any remotely reasonable person, even Toyota engineers, would think a Toyota vehicle's lifetime would be somewhere around 200k-300k. At some point they had to have some finding or evidence and convinced themselves the tans fluid would last the life of the pickup. Things turned out how they did and they had to back track on it. Now I'm wondering about the interval to change fluid. There are people that think it's needed around 30K, some as high as 100K. The 30K just seems so completely overkill. Have we really gone from never needing to change it to needing to do it every year or two? I know being wrong can cost you a trans but I just have to believe the number is much closer to 100k, than it is 30K. I'd really like to hear what others have to say about the lifetime fluid and now our fluid change interval.

Also, for original owners, has Toyota ever offered lifetime trans fluid changes due to them due to them falsely advertising them as lifetime fluids? Seems like some lawyers could make them.

 

Refer to the Toyota maintenance guide the service department provides. They specifically call out changing at 30k interval with regular towing and 60k interval for minor towing. It’s all in there along with other things that should be inspected/changed every 30k interval.

 

Yup, at least on my sealed trans, 60k miles, 30k if towing, and use only fluid with WS designation due to lighter viscosity.

 

PS - CCN's take on it:

https://www.youtube.com/watch?v=eRxSu4-4ojo​

 

Oh, and I know it's confusing, especially with Toyota putting out TSBs like this saying the life of WS fluid only calls for inspection at 100k for our '05-'06 1GTs at least....