I have a 2018 Buick Cascada. Got it new in the fall of 18. It now has 450 miles on it. Every fall I get a service engine light on telling me to change the oil. This years oil has 120 miles on it. Really, that oil is virtually new. How about the oil sitting on store shelves for over a year. Is that expired? Does it only expire when I open the cap? All of us have oil on the self in the garage. Should I throw out anything over a year old? The Cascada does have a turbo so fresh oil is important, but.... Take the oil out of my Cascada and put it in one of my non turbo cars? What do you think?