To calculate a distance-to-empty of a vehicle more precisely.

When three conditions of a condition that warm-up of an engine is completed, and moreover, a speed V of the vehicle is in approximately fixed steady travel, a condition that a gradient θ from a gradient sensor is 0%, and a condition that a window is closed are established (steps S100-S120), a standard travel resistance curve line is set by using travel resistance Rtr1-Rtr3 in the steady travel in vehicle speeds V1-V3 in the steady travel, and the vehicle speeds V1-V3 in the steady travel (steps S130, S140). Thus, the travel resistance can be calculated precisely, and a distance-to-empty can be calculated more precisely.