Hi Vijay, There is no fixed criteria of determining the maintenance cost of a car, as it varies from user to user depending on their particular driving behavior.
Among the shortlisted cars, each of them has their own pros and cons, and selecting one among them totally depends on your requirements and preferences.
If low maintenance cost and good after sale service is what you are keen on, than Maruti Swift will be the best option for you. On the other hand, if passenger comfort and quality interiors are on your top priority than you should go for Hyundai i20. Finally, if looks, style, road presence and powerful performance, is what attracts you the most, than Fiat Punto is the best option for you. For a detailed comparison of these car please click on the link given above -
Compare Hyundai i20 with Maruti Swift and Fiat Punto Thanks,
Initially, Hyundai Elite i20 Magna comes with a petrol and diesel engine but a CNG kit can be fitted with the one which has petrol engine. You will have to sacrifice with power to get more fuel economy and if you convert a petrol car into a CNG car, you may loose the warranty on the car and resale value of CNG cars is lesser than petrol cars. It is always recommended to get the CNG kit fitted from the authorized service center so that you can avail the warranty services as well. Moreover, the performance will depend on how the car is driven and maintained.
Click here to find the nearest Hyundai service centre by selecting your city in the drop down list.
How much fuel goes into a car varies on a lot of factors. Now you haven't mentioned how many km did you drive post the low fuel warning light as that could also determine how much fuel goes into the car. Even though the manual says that the tank capacity is 45 litres, the amount can vary by a small margin, give or take 2 or 3 litres. Also filling fuel in the hot day or in the night also makes a difference considering fuel expands during the hot day and contracts when the temperature is cooler. All said and done, make sure you fuel up within 3 to 4 km after the low fuel indicator light pops up.