Hello Mr. Munshi,
Nissan Micra is one of the best hatchback in its segment. It comes equipped with almost every premium feature and is available in both petrol and diesel fuels. Furthermore, it is the first hatch in the segment to receive a CVT automatic transmission gear box. To know its features in detail, Kindly visit the link below: -
We encounter similar question many times, the easiest way to increase the mileage is to keep your car healthy. Keep the tyre pressure proper, air filter clean, always follow speed limits and turn off your engine on traffic lights. Find more tricks here- Please find the details Chevrolet service centers here- http://forum.cardekho.com/topic/356-how-to-increase-mileage-of-your-car-tips/
There is not any special petrol recommended for NIssan Micra. You can use simple unleaded petrol in it. However, you can use Speed, Power or Extra premium petrol for better performance of the vehicle.