OT...good points Penguin.
Ah, we all loved GS oil, and many of us still ran after the higher viz range was found out. My Hondas do have the same oil circ for engine & trans, but my HDs run separate trans fluids; maybe due to their age, but the HDs really seem to run smoother with fresh oil. Conversely, my Hondas seem to shift more smoothly with new oil, though both have abundant power vs.
the HDs, so the engine diff is not noticeable.
All good for discussion.

I would not look forward to a diesel X5 oil change or, air filter change.
All you diesel guys deserve an award from BMW for your early adopter status and leap of faith!
Good Luck, mD