I'm looking for guidance on an oil weight for my son's 2014 Subaru Forester Limited to reduce oil usage. He recently purchased the vehicle with 166,100 miles. He has 1,671 highway miles on the oil change he did when he bought vehicle and today he is down exactly 1/2 liter and we added 17 ounces to top it off. The oil and filter he is using is;
0W20 Valvoline High Mileage Full Synthetic (0W20 is the recommended weight)
Fram Tough Guard oil filter
His plan is to use a 5,000 mile OCI.
1. Should he stay with the 0W20 and add oil?
2. Can he move to a different weight, e.g. 5w30, to reduce oil consumption?
Thank you for your thoughts and recommendations.