Originally Posted by Multibeemer (Post 750748)

Very interesting discussion that has provided a lot of food for thought. I was all set to do the partial flush using the VW/Audi fluid, but after reading these last few posts, I'm no longer convinced it's necessary, or even a good idea. Need to think on it some more...

Oh, and by the way, that link to "Sweet source for Esso" is very old, and it no longer works.

Originally Posted by JCL (Post 750312)

Many. And those transmission failures that have been reported, at any mileage, don't often sound like fluid problems. They often include reports of failed sensors, software problems, broken housings, etc. I am waiting to see a transmission failure caused by old or oil. BMW transmissions seem to be fail at random mileages, and fluid problems would shift the failures to higher mileages, with a more consistent failure point.

I don't believe it is because of the filter design. I think it is because things like the transmission cooler (with a temperature regulator), the lockup torque converter (far less heat into the system), the shift programming (crisper shifts, less wear on the clutches and less heat), and so on.

Originally Posted by Rockmelon (Post 750896)

thanks. i wonder what is the longest mileage that anyone had clocked on their X without changing tranny oil and the tranny still works without a prob. so far, the highest seemed to be around 160k miles.