My 2015 5.3L Yukon recently started burning oil after I switched to penzoil UP. I've owned the truck for 10k miles now (at 63k currently, purchased with 53k). The first oil (done at dealership where I bought it) went 4500 miles without burning more than 1/2 quart. I added a JLT catch can, but would mostly just dump the oil back into the valve cover since it was very clean looking. I had a free oil change so that was done at dealer again and no issues. 1200 miles ago I changed the oil myself using an OEM filter and Penzoil Ultra Platinum 0-20w oil. I used this in all my previous vehicles and had great luck with it, always seemed to make the engines run quieter and smoother. That said, I've added 2.5 quarts since I changed the oil 1200 miles ago. I couldn't believe it, but after adding 1.5 quarts after 500 miles I then needed to add another quart at 1100 miles. Now at 1200 it's showing near the bottom of the safe zone again.
It is not leaking, I've checked over every inch of the undercarriage and it's bone dry, no drops under the vehicle in the driveway either. I'm not noticing any blue smoke and the truck is running fine(ish). It stumbled the other day and threw a code for cyl 7 misfire, but it went away immediately and has been fine other than that.
Any suggestions? I'm assuming these 5.3's don't like penzoil UP perhaps, what should I do?