hi just wanted to know if anyone has issue with oil consumption seem to have to top off quite regularly. seem odd had a buick 1989 delta 88 and never had to top off always stayed on full and it had over a quarter million miles on it. the malibu has 219,000 on it not smoking or anything dont smell oil burning out of the tail pipe no external leaks that i can see. changed pcv valve. is this normal for these cars? thinking of moving to 10w30 instead of 5w30 or 10w40 any thoughts on this?