HI there Tom,
This is still unacceptable, and I would recommend that you start an oil consumption test with your local c5 dealer, and document the condition.
GM states that using less than 1 qt in 2000 miles is acceptable, if you are using more than that, it is not right.
Best to ya, c4c5
I have 7500 miles on my car and I had to add oil at just under 2000 miles after my last oil change. I read on another thread that when the dic low oil warning light comes on, the car is low one qt +/- .5 qt. Since I can't read the damn dipstick, I don't know if I'm low .5, 1 or 1.5 qts. I just add a qt when the warning light comes on and wait util it comes on again. If it stays around 2000 I'm fine with that. 3000 miles as c4c5 states would be better. Switching to 10-30 has helped a little.