I've been putting in Shell 91 (or "v-power", whatever you want to call it) since day 1 with the car.
I do 80% highway driving, and for the 20% of city drive, I don't go foot heavy on the pedal.
Max mileage I got a tank was 650 km.
850 km just sounds not possible to me, even if it's a single trip 100% highway.

 

Even straight highway, 850km seems high....although might be possible if it was run bone dry. I've run it well over 700km before filling with highway only, with a bit of room left. City driving will kill the mileage....if all I'm doing is driving to/from work through town, the mileage I'm getting is pretty brutal.

 

Sounds reasonable, and very comparable to mine.
I'd love to get 850 km out of a long trip though, but i just don't see it happening.

Have a good weekend guys