BaltimoreSilverado

Just finished my first "official" oil consumption test through the local dealer. They reported that my truck consumed 1.5 qts of oil over the test interval as opposed to the .5-1 qt I've measured. (In all honesty I did drive more during February than I have over the last 12 months, but it was mostly highway mileage back and forth to western Ohio.) To make a long story short the Service Manager recognized the "validity" of my concern over the oil consumption, but said his hands were tied as the amount of oil used was "acceptable" to GM.

I have a 2011 Silverado 1/2 ton with an aluminum block 5.3L AFM engine. Bought the truck new in January 2011. I've put approx. 24,300 miles on it and the last three oil changes I've noticed that its been between 1/2 qt. to 1 at. low. I use Mobil 1 5w30 with a 4,500mi to 5,000mi oil change interval. Have not seen any change in fuel mileage since purchase. Truck gets a steady 15.9 mpg all around. My '06 Silverado 1/2 ton 5.3L went over 150K miles and did not consume oil. The '06 also got about the same mpg as the '11. While the fuel mileage is not a concern, the oil consumption is. Dealer keeps telling me that 1qt every 2000K miles is acceptable. I've never had a new engine, or an engine that was not clearanced, use oil like this.