I own a AT Picanto and in my 8 months ownership have driven it close to 25K and all around PK. I have a very light foot to paddle.
1) It's a comfortable car but not comfortable to be driven at 120km/h speed.
2) You get about the average of 13-15km/l with 120-130km/h speed.
3) In city traffic drive, it doesn't give you more than 10km/l average.
I've not driven other AT Picanto long enough to comment on fuel average but in my opinion, my car is not giving optimum fuel average considering the engine size, technology and marketed fuel average.