Hi all, just wondering, why has my oil consumption varied? I've been using Wal-mart super tech synthetic for over a year now. I change the oil every 5k miles. I usually have to add a quart around the 3k mile mark. However, this time around, I'm almost at 5k miles and haven't consumed a drop. Its still full. What gives? Trust me, I'm not complaining, and actually quite happy. I know the truck has been using dino all its life until I purchased it last September. Thanks