Bro talking about my own experience..
I recently sold my Japanese Alto and it used to gave me around 16-18kmpl in city without AC. I have managed to get 18kmpl from it and i have also managed to get 11kmpl from it. I have 2 corolla Gli in my home.. One gives around 14.5kmpl with AC (Highway and city driving mix) and other gives around 12kmpl on same driving conditions.. And when i drive corolla it gives me 9kmpl.. I also have Euro 2 mehran in my home and once i managed to travel around 60km in 300rs fuel. I had PKDM alto previously and it used to gave me around 4-5kmpl.
So basically mileage depends on how you drive the car. If you are light on peddle then mileage will be on higher side.