Hi Mr. Azim,
This is in regards to your query posted on the website CarDekho.com, we would like to inform you that at present there is no Nissan Dealer available in Lucknow, so can you can contact with Nissan Dealers in Gurgaon or Delhi. You can use the given link to check the Nissan Car Dealers.
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/