2007 was first year. Wife bought a new z71 then. Got rid if it at 95,000 miles. It went through a lot of oil, first noticed at about 60,000 miles. She was going to do the oil consumption testing before 100k warranty was up but we traded it off instead.
Personally know 4 others that HAD 2007 5.3l and every one consumed oil.
There is a reason if you google search "2007 5.3l" that google then auto populates with "oil consumption" as most popular search. I don't know when/if they solved the issue, as I haven't been in the market for a gm 5.3 since then.
