It's interesting that in years past when the customer paid for maintenance, BMW recommended shorter oil change intervals. Now that they
are footing the bill, oil change intervals have lengthened. Draw your own conclusions from that.
My oil change philosophy comes from my late father, a life-long mechanic. As he was fond of saying, "Oil is cheap. Engines are expensive."
So I changed the oil (myself) in our X3 at 1,500 miles and again at 4,000 miles. Didn't do an analysis, but the oil was pitch black both times. I'll probably change it again around 7,500 miles. After that.....for "mature" engines I usually change the oil every 9 months or 7,500 miles, whichever comes first. Synthetic of course. (Mobil 1 0w-40)
At around $45 per oil change, I consider it cheap insurance.
As always, your mileage (and opinions) may vary.