I have a 2010 Clubman,oringinal owner, with 45K miles. drove to Fl. last month, serviced car before trip put about 1700 miles on it and noticed strange noise from engine. Then oil notification stated extream low oil . Shut off enging immediately, checked oil level. Now get this it was DOWN 3 1/2 QUARTS. I do most of the maintenance and change oil every 7K not ever adding oil between oil changes.
No oil leaks, or engine exhaust smoke. Checking every day now and using about 1 quart every 500 miles.Any thoughts on what this can be???? Please give helpful input. Thanks

 

7k is a little too much for oil changes, in my opinion. I never go beyond 4500 or 5k even with full synthetic oil. As for the reason, can you see the tail pipe carboned up? Could it be the pcv?