I have a 2009 Silverado with approx. 47,000 miles on it. Initially it didn't use any oil and then it would be about 1- 1.5 quarts between oil changes. My oil changes are the 5000 mile mark not the 3000. Just recently I was due for my oil change but went on a small road trip for the day. I got the dreaded oil pressure drop and alarm going off. Scared the crap out of me. I had already added the usual 1-1.5 quarts of oil about 1000 miles prior. I looked at the dipstick and it was below the hash marks just registering on the dipstick. Luckily I had some oil with me and was able to get back on the road. I have just started the oil consumption test with my dealer. I must say so far my dealer is being outstanding about it. We will see how it goes. I really do like my truck and hope this can be remedied.