This is for my 2010 Traverse. Oil sample taken at 152,653. Ive included all of my UOA. My interest in the UOA- is to monitor for elevated iron levels-- pointing to timing chain wear. As can be seen the engine now uses more oil. I check the oil levels weekly and make sure its stays up. Seems that folks with these engines- who do not monitor oil levels-- end up with worn chains. The current oil now in use is Valvoline Max-life 5W-30 for high mileage engines. All other UOA are Valvoline Conventional 5W-30. I began to transition over to Maxlife with previous oil changes.... something like this. 3 qts VWB and 2.5 qts max-life 2 qts VWB and 3.5 qts max-life 1 qt VWB and 4.5 qts max-life 5.5 qts maxlife. Im guessing carbon buildup. Pieces have broken off and scratched the inside of the cylinders causing zebra stripping- leading to oil use. The vehicles current weekly driving is--- 5 mile drive in the AM- 15 min at most. Stop and go to the train station. 5 mile drive in the PM- 15 min. Stop and go. Weekend drives are a little farther.