I have noticed over that past 4 oil changes (I do my oil every 3-4 k miles), I don't believe in BMW Oil schedule! I have always noticed when I put in 7 quarts, the oil meter still shows that it is short .5-1 quart of oil. Now, mind you, there is a RANGE for safety on these cars. You have a Min and a Max level indicator on the car. I would fill the car up with the recommended 7 quarts of oil and then drive it for a few hundred miles. I have found that after driving the car for a while, the oil meter will eventually read the proper amount of oil in the car properly.
Keep in mind, if you OVERFILL your oil in the car, it can cause damage as much as if you UNDERFILL the car. Too much oil can cause pressure buildup and depending on how much you over fill the car, there can be serious repercussions. My advice is to drain the engine very well and then put in 6.5 quarts, run the motor for about 5-10 minutes and check the meter again. If still showing low, add the other half quart and drive car for a 100 miles.
Here is the OFFICIAL BMW recommended OIL brands to use! Don't believe all the BS on the forums, here it is right from the Engineers mouths!