Don't go for petrol engine very very low mileage

I purchased my car from M/a Khanna Hyundai Kanpur. The buying experience is ok but do not trust sales executives. He told that DRL lights can be fitted during 1st service but there service team denied. Even it will void guarantee if I will go for outside fitting. Company is also unable to provide CNG Kit even at additional cost. However, it gives mileage of 15 km/l in highways. Overall, it's an expensive car to maintain.