Well, about the 850 miles, if you know the oil consumption in these Mercedes Benz cars, with the 3.5 engines; then you would know that you CAN, as some have confirmed, possibly get as little as 400 miles on four quarts of oil. On my Mercedes, when the oil level gets to the bottom red mark on the dip stick, a yellow caution light on the instument cluster will come on to let you know you need to add some more oil and this, I am thankful for Mercedes adding this little oil light warning system, although I really wished there was no need for gadgets such as this on a premium series car. So, rather than checking and continuously opening the hood, which I don't like to keep doing every day or so, I'm going to go until the yellow light comes on, which means it is time to add two more quarts. Since you don't really know what I'm talking about based on your questions; you can count it as a blessing and rest assured that you don't have a bent rod, or bent piston or too much carbon or blown head gasket or bad egr or bad turbo or coolant/oil leaking into the cylinder or whatever is causing these engines to respond in the manner that SOME do,....yet. Anyway, I had expected the car to continue to consume oil at the beginning of the accumulation of the miles for a period of time right after the work that I did to the car. And I base this on the same premise that most rebuilders of engines take and that is; it sometimes take a good many miles before symptoms go away and for the engine to completely seal all of the components that relate to the oil consumption issues. Hopefully, everything will settle down and the car will stop drinking the oil and just consume a little oil or relative small quantity of oil over time, like regular oil consuming cars do (a quart every 1500 miles or so), which would make me mostly satisfied, since the car has such a great ride, even as it be drinking the oil. If it continues to smoke and consume oil, I am going to throw in the Billet Rods into the mix, if it is determined definitively that rod bending is the result of poor quality in the manufacturing process of the rods in the 3.5 engines that were imported into the United States of America by Mercedes Benz Motors and it is FOUND that the bent rods IS the culprit and source for the problem of EXCESSIVE oil consumption. I wonder was a strike going on at the factory, when these engines were built in the early 90’s?

BenzDiesel