Out here in Europe, Subaru
Out here in Europe, Subaru recommends, and the official Subaru oil, is, in fact 5-30w synth.
I burnt around a litre (quart) before the first oil change at 6000miles, and the car is used 90% on the motorway (around 85mph constant 3500rpm) - but that would be with the factory filled 0-20w. Since then, on 5-30w Subaru Europe Official oil - absolutely zero oil burn. That's my MY2014 Forester. Simple fact is the 0-20W is too thin, and getting past the rings. And all for what? A minor improvement in gas-mileage?