During hot summer months in Texas, I can consume a quart of 5W-30 every 2000 miles with some contribution from a valve cover leak. I now run the 10W-60 "M" oil June through September while we do our boat towing and average a quart every 3500 miles. Not too bad with more than 240,000 miles on the engine.

2002 X5 3.0 241,000 miles
2004 325i 107,000 miles