I have a '15 Legacy with the 2.5L 4-cylinder, with 44K miles. Per the US spec I have run 0w-20 synthetic since purchase in '15, with no issues (although I do think the engine is excessively loud at low RPMs). I believe I have read that Subaru's oil spec for this engine in Japan, Europe, and elsewhere is 5w-30. Can someone confirm this? I am considering using 5W-20 or 30 in this engine, going forward, as I live in an area (middle TN) that does not get super cold in winter, and the 0W-20 seems excessively thin for my requirements. The car sees an even mix of city and interstate mileage. Thanks for your input!