I am having the same issue with burning oil. It seems it is getting progressively worse. Every 700 miles or so my oil light comes on after I shut off the car. I check the dip stick and the level is below normal and I would put about 1 quart back in. I've already changed the PCV (aka oil separator) but it didn't fix the problem. I am using Synthetic Castrol 10W-40. I know some say to use 5W-30. I'll give that a try and see if it improves things. Hard to believe a slight difference in oil viscosity will make any significant changes.
My car has about ~114K miles.