My two cents worth, change the oil again and be sure it is full "again". Check it every 1000 miles or so and see what happens. Be sure the full 8.5 quarts of Mobil One 0W-40 are put in. If it uses excessive oil again, go to 5W-40. Someone may have run it with incorrect oil or low oil, in the past, and caused excessive engine wear. A second go round should let you know where you stand. You might also drop the pan under the engine, just for piece of mind.