A vehicle includes an engine, a continuously variable transmission including an endless belt to output a power from the engine, and a transmission to which the power from the continuously variable transmission is transmitted. If the vehicle travel speed is not smaller than a first threshold value and an accelerator opening degree is not smaller than a second threshold value, a controller determines that the continuously variable transmission is being used in a belt high-load situation. If a travel distance in the belt high-load situation is not smaller than a third threshold value, the controller determines that the endless belt is deteriorated or deterioration thereof is in an advanced stage, and a deterioration message about the endless belt is displayed on a display based on an instruction from the controller. A situation in which a speed changing ratio of the continuously variable transmission is not greater than a fourth threshold value may be determined as the belt high-load situation.