I have a 09 with the 5.3L.
I have always had the dealer change the oil and hardly ever checked it between changes.
I checked the oil one day and it was a quart low. I looked at the mileage from time of service until that day and it was 4,000 miles. At first I thought the idiots at the dealer shorted me a quart.
I put in a quart and checked it 2,500 miles later, and it is 1/2 quart low.
The truck has 66,000 miles on it, and I drive it easy and don't load it up or tow with it, just driving back and forth to work.