hey guys I was doing a search on zz383 oil consumption; when I happened to stumble upon this page, so I registered.
My zz383 which was purchased this year is having the same issue as many of you are having (It also has a summer 2012 build date). I have around 4,000 to 5,000 miles on it; and its eating about 1 quart per 400-500 miles. I'm not getting any smoke on startup/idle. but it is smoking on deceleration.
I spoke to GM they are doing a compression test/leak down test on it now at the dealership. It looks like GM really dropped the ball on this engine! I'm really upset; to make matters worse GM is trying everything to not pay up/fix the issue it seems.