All oil is sacrificial wear component. Lifetime ATF is a sucker play. They know every tranny will outlast the warranty, and most new cars require dealer tools to mate the new tranny computer with the main ECU. It's a golden goose. There are no TV ads selling ATF, so the people are ignorant. Nobody wants you to change your ATF, except you. All AT use ATF as the primary coolant. ATs get very hot so ATF is pumped up to the radiator for water cooling. Heat speeds the deterioration of the oil, just like in an engine.
The mfgs that do (or have) recommended changing ATF advise interval of 30k - 50k miles. I think 50k is too long based on my experience with Honda ATF. I also like to use intervals that are easy to remember when it's due. So I chose 33k as the oil interval for all gears. 33, 66, 00.
Changing the "lifetime ATF" in my 2008 BMW 328 at 130k made a huge improvement in driveability. It felt like adding 50HP. The old oil was burnt and black. I change it at 33k now. It has a GM Made 6 speed, so I use synthetic Havoline meets the BMW spec, cheapo from Amazon.
I followed Honda advice to change ATF every 30k in my 2000 Odyssey 4sp, but the dealer only did 1x drain/fill, instead of Honda recommended 3x drain/fill/drive. Doing one drain/fill only changes half of the oil and the Honda oil at that time was non-synthetic Honda Z1 ATF which was not good enough for their new trans with the new VTEC V6 and the new 'world's biggest' minivan. The dealer never recommended I change the ATF, I had to ask for it based on reading my own Bentley repair manual. I assume other owners of same tranny never changed the ATF, and we know what happened to them. At 90k after 3 ATF (half) changes mine started shifting funny, so I started doing my own flush with aftermarket synthetic ATF, catching the old oil from the cooler return line, and the deterioration stopped. It still runs fine at 250k, with the original transmission. Valvoline Synthetic ATF, good stuff!
BTW if you haven't yet tried the new Pennzoil Platinum (Shell - Dutch Oil) motor oil made from natural gas, you should try it. Using natural gas stock instead of crude oil stock allows the final oil to be much more pure, with less contaminants, more concentrated with lubricant molecules. This is what BMW uses now. I used to notice a bump in smoothness and power when I changed my motor oil at 5k, with Mobil1, or Castrol Edge. Now with Pennzoil Platinum I don't notice any bump in power after oil change and the car feels stronger all the time. My valves don't tick anymore, I used to have to run it at 4k rpm for a few minutes to blow out the small oil galleries to stop the ticking, but now it's not necessary. The oil is not burning and gumming up the small oil channels. It runs much smoother on very cold startups too. I still change oil every 5k, but I feel like it's much better protected with this new Penzoil stuff. ymmv literally
