Ok, this is long distance, when I recently drove my 325i from Jo'burg to cape town, we had to stop and fill up twice. We left Jo'burg with a little more than a quarter tank and arrived in Cape Town with a little less than a quarter tank.
So I reckon we did about 700km to the tank, which isn't bad at all. Which was confirmed by the onboard computer telling has the consumption was 12 to 12.5km per litre.