So, I am borrowing a Subaru from a dealership while my car is being repaired and noted that the dipstick was dry. Bone dry. At a bit less than 16K on the odometer. No warning lights are illuminated on the dashboard; there is no obvious sign of a deficit of oil. If anything the car has a noticeable whirring noise at 65+ mph; maybe that is related to AWD transmission. Definitely not the same or similar to turbo noise which I am quite familiar. I am an AWD noob, though. Owner's manual says to use 0W-20 synthetic at oil change intervals, but topping off with 5W-20 or 5W-30 conventional is fine. So, this evening I topped off the oil with conventional 5W-30 that would otherwise go in the retired S-10; it took 3.25 quarts to reach the full mark. IMO this is more than topping off, as it is about 60% of the crankcase capacity. Fuel economy has been about 25 mpg over the 290 miles that I have driven it (all highway, all 87 octane, northern Ohio winter gas formula from BP), which is about 2 less than the government rating. Oil on the dipstick as I checked progress of the top-off appears very dark. I would assume that normal maintenance has been performed up to this point, and that all driving prior to mine has been as a rental car in the city. I will probably perform an oil change this weekend; the question is, do I tell the dealership any of this? They have given me the loaner on an indefinite / unlimited mileage basis while parts are on order and repairs are being done on my car. I am grateful to the dealership for extending this courtesy. I wonder if this is normal for Subaru engines. I have had thoughts of buying a Subie in the last year or so. Would anyone care to comment? Is 0W-20 synthetic oil commonly available at Autozone or Advance? Does Subaru have required or preferred specifications for oil, e.g. VAG 502.00?