Explaining how the transmission adapts is helpful and interesting-thanks for posting. That's is more detailed than I have read.

I am not challenging that fluid can be used a longer period of time if because of the fluid itself or the ability of the transmission to adapt to fluid performance.

My position to change the fluid is based on fluid degradation over time. I have explained how I came to that conclusion so I don't think there is any need to do it again.

The adaption capability is a great feature to extend transmission performance. As I read the how and why the transmission adapts, it also appears to endorse that part of the reason the transmission has the ability to adapt is the fluid does not perform as well over time. That when the transmission can no longer adapt the message is that the fluid is out of spec seems to be additional input that fluid degrades.

I picked 50,000 miles for a change interval out of the air. My logic is the fluid has lost enough performance that new fluid will be a worthwhile investment. I know there is not enough reliable information to verify that point of view. On the other hand, I don't think there is enough reliable information to take the position it is a bad practice. I don't think you have even implied that either, have you?

Just as you said it could be a good practice based on what I drive, it may not be worthwhile if the engine is, say, a 3.0. If I had a 3.0 I would at least extend the interval but check the fluid as often as I do now.

I don't believe in resets either, updated software yes, resets to fix a problem-- natta.

Brandon, I don't see this as banter. I think it is constructive. I respect JCl's contribution and I believe he does mine. I don't take it personal, do you?

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas