In Mehran Euro2, you can achieve as low as 11kmpl and as high as 17kmpl with AC. I live in Lahore and my daily commute to my college is 5kms. These 5kms involve signals, continuous braking due to traffic, and short gears. In such conditions, I get 11-12 kmpl with AC. ( please note that I have a very soft foot on gas).
However, a few months ago my daily commute was increased to around 20kms one way. These 20kms mostly consisted of a long patch of main road without too much braking or gear shifts. During this time, I achieved 15-17kmpl with AC.
I would say that since the engine is small in Mehran, constant acceleration and deceleration can be a bit problematic as far as fuel efficiency is concerned. But if the speed is kept consistent without hard braking and constant gear changes, the average can go considerably up.