When idle, especially at traffic lights, it's better to put the ignition off, rather than wasting precious fuel. This will not just save your fuel, but also help in curbing pollution, which is the need of the hour. Plan your journey, even if its from home to office and back. Make a note of all the things-to-do on the way in your plan, this will save you a trip and thus, save your fuel. Driving efficiently is by far one of the best measures to add to the efficiency of your vehicle, the other being proper maintenance.