I have an 03' Sentra Spec-V w/ 150k. Car runs phenominal. No smoke, no leaks. However, it uses 2quarts of oil every 2 weeks. I recently topped it off, then checked it again the next day, after it had set all day while I was @ work, and it again read 2 quarts low. I drove to the parts store to get oil, & when I came out to fill it up after the car was warm, it showed full ... WTF? Any ideas would be appreciated ...