Hi,
When I had the silver Aurion actually a few weeks prior to its write off, you can see attached the image of my fuel economy when driving from Victoria Park to Stirling to pick up mate then driving to Bunbury for lunch on the long weekend. My mate could not believe how low my fuel economy was and he remarked it betters his Ford Focus's economy. That fuel needle did not move a spot until I was driving back home! By the time I got home, it was between full and 3 quarter mark.
Now I have a new Aurion so I have yet to comment on its fuel economy cos it is still new (picked it up with zero kms - now 600 kms). I would wait until after 1,000 km mark as it should free the engine up.
Cheers
Dave