When detecting and recording vehicle data items corresponding to evaluation parameters for fuel-efficient driving (the parameters may include, for example, the speed of the vehicle, the average engine speed during an upshift, or an idle time), it is determined which one of first to N-th preliminarily-set traveling conditions (which may be, for example, highway driving, open-road driving, or idling) a current traveling condition belongs to. The vehicle data items are then recorded according to the determined traveling condition. The amount of fuel consumed in the corresponding traveling condition is also recorded. Each of the vehicle data items of the corresponding traveling condition is given an evaluation score with respect to an evaluation standard. Each evaluation score is then corrected based on a rate of fuel consumption in the corresponding traveling condition. Thus, the evaluation score is corrected in view of the traveling condition. Accordingly, this achieves a proper evaluation for fuel-efficient driving.