I’m over 150k and I tow A LOT.
Still on the original 2011 fluid and guess what? I don’t ever plan on changing it. I’ll keep you guys posted lol.
Runs absolutely perfectly BTW.
My 2010 is also on the original fluid with 124k miles and I towed a 1200 lb aluminum fishing boat (total GVW including motor & trailer) about 12 times. I considered going to my local POS dealer, but since the punks that work there can't do anything right, I've decided not to change it. If Toyota claims that its tranny fluid is good for a lifetime, then I'll be happy to get 300k out of it. I think that it will be fine.