I spoke with an Australian Subaru dealer, big one, and I now use what they use. It's not expensive but I am very happy with the noise level and the car uses NO oil.
Havoline C3 Fully Synthetic 5w30.
Make sure it's the C3 one though. Their most up to date spec oil.
For reference.. mobil1 5w30 is about $87/4L here.... the Havoline was $47.. and I prefer it over the Mobil1 now. You can only buy it only through Caltex Service Stations here.. for any aussies wanting to know.