The date and milage I gave was an estimation, but what happen to me was I always keep my oil changes up to date. It was time to change the oil and I checked it, and lo and behold, it was just under the add line. I've never had this happen before. The engine never used up oil until that event, I had a mechanic check it out and he told me that he's seen this problem in the Kia Sorento many times. The car doesn't leak oil, the car doesn't smoke, I have no idea where the oil goes. I'm using about 1 to 1 1/2 quarter between oil changes. My older brother has a Kia Sorento the same year and his engine out of nowhere used oil and the engine blew, though Kia did put a used engine in for him.