FUEL-SAVING DRIVING DIAGNOSTIC DEVICE, FUEL-SAVING DRIVING DIAGNOSTIC SYSTEM, TRAVEL CONTROL DEVICE, FUEL-SAVING DRIVING RATING DEVICE, AND FUEL-SAVING DRIVING DIAGNOSTIC METHOD

A shift lever position determining unit determines whether a shift lever position of a vehicle satisfies predetermined conditions. If the shift lever position is determined to satisfy the predetermined conditions, a travel distance adding-up unit adds up an optimum shift lever position travel distance. If the shift lever position is determined not to satisfy the predetermined conditions, the travel distance adding-up unit adds up an inappropriate shift lever position travel distance. A fuel-saving driving rating unit rates driving by a driver based on each added-up value added up by the travel distance adding-up unit. A fuel-saving driving advice generating unit notifies the driver of fuel-saving driving advice together with a rating result in accordance with the rating result. Therefore, it is possible to encourage the driver to select an optimum shift lever position with high fuel efficiency and thereby to improve the driver's knowledge and awareness of the fuel-saving driving.