The Nissan Micra and the Ford Figo Diesels are both good buys, the Figo has more cabin space and better drive quality while the Micra has more outright power and better performance. The Figo also gives you a large car like drive feel.
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/