Salam,
it actually is no brainer to understand.
City is a pretty efficient car and 1.5 engine in the city is better than the 1.3 engine as 1.3 engine has to work really hard to move the car.
the figures came on with GT road driving and the rest of 300km on disgusting potholes of interior punjab roads.
i am prettty sure if one drives 70-90 on motorway he can achieve 30km/l 
people hit the paddle and floor it and cruise at 110-120 on motorway and complain that the car is a fuel guzzler where as 110-130 km speed is no where close to a hypermiling speed
stocks are 175 i guess but mine is on 185 continental tires. city suspension is very uncomfortable specially for punjab roads but tires do compensate little in the suffering.
Salam,
On google map its shows 172 km but if you actually drive to mandi bahauddin via Kharian and go zig zag from rasul bairrage because the roads are a mess and you have to take a 100km extra detour from pind dadan these days because the roads are being re-done.
the to and fro trip comes up as 760km
This mileage is no brainer for anyone, as i said my city is in complete stock condition.
i get 14-16 inside islamabad where people claim to get 11-12 from 1.5 auto tranny.
i guess the city stock size are 175. i have continentals installed in my city which are 185 and are giving supreme efficient milage and are really comfortable tires. even though city is a very uncomfortable car but tires do make the suffering a little better.
yes true, 185 is the max you can go in city. that too on 1.5 engine, i am pretty sure 185 will be hard on 1.3 aswell as the city OEM recommended tire size is 175.
