Very low Milage

Very low milage. Only getting 7.5 km/l . Not good milage. also no fog lamp inclusive. while the time of purchase showroom was inform us the milage per litre is 10 km/l. But after purchase it never gives us a milage as committed. Only on mega highways it gives us 9 to 9.5 km/l. Everytime we are checking fuel efficiency with different petrol pumps but never gets above 7.5 km/l. My model is 2.7 G AT 8 STR. Hence this model not economical.