milege offered by company is less

Look and Style perfect Comfort perfect Pickup good  Mileage i am using a ford figo titanium diesel and i bought the vehichle a day ago and the company is offering a milege of 20 km and i give about the diesel of 1500 about 30 litres and the car is indicating that it can only run 384 km after the trip of 111.3 km.and it indicates it only gives a milege of 16.5 km  Best Features central locking ,fog lamps,air bags,abs system,music player,etccccc only defect is milage Needs to improve milage. does my problem of milage cured by the first serviceeeee Overall Experience good and perfect expect milage