I have noticed something I find baffling....on my 96 Q45 oil consumption is not linear at all- for instance on a fresh fill of Redline 0w-30 oil is 11 ounces low after 2300 miles of use{which I measure and refill} then the next 1000 miles of driving consume 15 ounces....driving pattern is identical which consists of a 120 mile daily roundtrip all highway at speeds of 80-95mph. This pattern has been similar for almost every oil change interval,any ideas????