I have a 2017 Mazda CX-5, 2.5 L Trying to figure out where the oil goes between oil changes. The CX-5 has 160,000 miles on it. Yesterday I did an oil change on it, there was only 2.5 qts left in the oil pan, it requires 4.8 qts per oil change. It’s continually done this for a couple of years now. I’ve been pretty good about getting oil changes done every 5000 miles. Doesn’t smoke, runs great, never seen the oil light come on, never had a problem with it. I use Super Tech Full Synthetic oil 0 - 20 weight as required. Is it an overactive PCV valve? Could it be the oil or is this normal. Thought about using 5 -30 weight, I don’t know if it would help. This is the second time I’ve had a car do this.