I found the same thing happening. When i first go my car i wanted to try the full synthetic oil. In a few weeks of driving the "check oil" message came on and the oil was low, which really bothered me. I checked and the car was not smoking and was not leaking on the ground. I figured that maybe the full synthetic may be better resisting breakdown but it seamed to be a "thinner" oil. I then switched to vavoline high milage 10w-30 non-synthetic with .5 qt of STP oil treatment which seamed to reduce the consumption and just recently tried Quaker state high milage with oil treatment additive and that seems to work even better. This may not be the answer but it make me feel better that the oil is not disappearing as fast.