me too running viva elite 1000CC (auto). yes average consumption is like 12 in the city. But I went to kandy and it did like 15+. Also pulling power is bit low before the first service. But the pulling power got increased after the first service. One of the guy who at the service center told me that the car will get in to its optimum level after the third service. I stay below 3000rpm all the time till third service. Also I'm running 90oct and I have no issues with it.
Thanks