The Maruti Suzuki Dzire tour will return 15-16 kmpl in high traffic conditions of Delhi and it may increase with the highway travelling, that comes nearly to 19-20 kmpl. The best ways to avoid fuel wastage is by driving it in the right gear at the right time. You can shut down the car's ignition when on traffic lights to avoid a lot of fuel wastage. Even riding with proper amount of air in the tyres influence the mileage, with less friction in case of proper inflation. You can get your engine oil checked and car serviced at regular intervals of 10,000 km or 1 year, whichever comes early. Try to maintain a maximum speed of 70-80 kmph for best mileage and speed combination.