If your major concern is fuel economy, do not consider 1l turbo cars or crossovers. You never get hybrid like fuel economy from these vehicles.
However, if you drive very carefully you can achieve a good fuel economy but these cars have healthy torque and decent power and very good handling specially in the corners. Even though you try to drive very carefully, your inner beast never let it and you always want the aggressive drive and the fun associated with these cars.
Once tried the careful driving (it is not a Civic, a different heavier, car with 1l turbo engine) and it achieved around 18km/l from Kottawa to Hambantota, mixed driving in highway and normal road to hambantota from Matara but drive was not that enjoyable.
On the way, had some fun and fuel economy was around 12km/l