Given the car is in good condition, driving style will really make a good difference. Assess your driving habits from time to time (you can check for references here and on other sites on the internet).

Traffic is also quite bad already. Our M/T Altis hits around 8++ to 9 km/L in the city (morning and evening CBD traffic). If your car does nothing but city driving, maybe you also have carbon build-up as well (that can affect FC in the long run). Taking it out on a long drive after a tune-up or doing some hard, high rpm runs will help.... or you can spend for decarbonization.