I own a 2015 Maruti Dzire (facelift). The car has been returning a mileage of 18-19 km/l in the past years, but suddenly from the past 3-4 weeks, the mileage has dropped to 15km/l. The car is used for daily commute of around 30-40 kms without any sort of high speeds (60-80 km/hr is the max) and without any harsh acceleration. The car has followed the service schedule religiously and has covered 70,000 kms till now.
Any possible reasons for the sudden drop and possible solutions will be appreciated.