2006 WRX STI Stock 60,000 miles. A couple of months ago my cruise control check engine light came on. I called Subaru and they said to check the oil and it was low. I put a quart of oil in and the light went off. A week later I brought the car in for its oil change. I use 5w30 synthetic. That was a couple of months ago and now the light is on and I am low again. Should I just add some oil or bring it into Subaru? Prior to this the car never got low on oil between changes.