I really don't know why I'm back on this post.
I suppose since you all want to think coolant when the story says otherwise, I should advise you to stand behind the car and smell the cloud. If its a "white" cloud of oil smoke (as anyone who has ever seen this much oil smoke would call it), it will smell like it. If its coolant/water it will smell totally different.
MB V8s have well known valve guide oil seals problems. They also are well know for being the last motor in the world to get a head gasket problem. Since your oil consumption indicates that you have a V/G oil seal problem you might just have it fixed since it is relatively inexpensive. Then, since your cloud will have disappeared you can look for your coolant leak.
Bosch Master, ASE Master, L1
33 years MB technician