I have suzuki Cultus 2020 VXR
I am facing an issue with the mileage it's not exceeding 13.6km/L with AC in the city also on the long route. I bought the car along with my friend he's also using the same model. he gets 16-17 in the city and on long routes he gets 19-20 km/L.
I changed different fuel stations from time to time to check fuel quality, maintenance is on time.
what will be the possible cause?