FWIW, I also use Mobil 1 5W-30, and I change every 5K, regardless of what the car's oil monitor says (it often says I have over 40 or 50% remaining). It's an easy reminder of when I need to change, whenever the odometer reaches a multiple of 5K. Might be a tad bit too often, but I figure oil changes are one thing I have easy control over, and too often can't really be bad.