A navigation apparatus including a wireless communication unit configured to wirelessly communicate with an entity; a controller configured to search a plurality of candidate paths from a current location to a destination from map data, and to calculate a fuel consumption index based on multiple road information conditions for a corresponding candidate path from the current location to the destination; and a display unit configured to display the calculated fuel consumption index for each of the plurality of candidate paths. Further, the fuel consumption index indicates an estimated amount of fuel used to travel the corresponding candidate path.