A road vehicle comprising: an internal combustion engine; an electric starter motor, which is coupled to the internal combustion engine and can be operated to start the internal combustion engine; a high-voltage electric circuit provided with a first storage system; a low-voltage electric circuit provided with a second storage system, which has the same nominal voltage as the electric starter motor and is directly connected to the electric starter motor to directly supply power to the electric starter motor without the interposition of any conversion device; an electronic DC-DC power converter, which connects the low-voltage electric circuit and the high-voltage electric circuit to one another to transfer power from the high-voltage electric circuit to the low-voltage electric circuit; and a control unit configured to detect a turned-on condition of the road vehicle and to detect a cold-start condition of the internal combustion engine; wherein, in the absence of the cold-start condition of the internal combustion engine, the power to be supplied to the electric starter motor is only and exclusively provided by the second storage system; the road vehicle is characterized in that the control unit is configured, in the presence of a turned-on condition of the road vehicle and when the internal combustion engine is off, to activate the electronic DC-DC power converter so as to transfer power to be at least partially supplied to the electric starter motor from the high-voltage electric circuit to the low-voltage electric circuit only in case of the cold-start condition of the internal combustion engine. an internal combustion engine; an electric starter motor, which is coupled to the internal combustion engine and can be operated to start the internal combustion engine; a high-voltage electric circuit provided with a first storage system; a low-voltage electric circuit provided with a second storage system, which has the same nominal voltage as the electric starter motor and is directly connected to the electric starter motor to directly supply power to the electric starter motor without the interposition of any conversion device; an electronic DC-DC power converter, which connects the low-voltage electric circuit and the high-voltage electric circuit to one another to transfer power from the high-voltage electric circuit to the low-voltage electric circuit; and a control unit configured to detect a turned-on condition of the road vehicle and to detect a cold-start condition of the internal combustion engine; wherein, in the absence of the cold-start condition of the internal combustion engine, the power to be supplied to the electric starter motor is only and exclusively provided by the second storage system; the road vehicle is characterized in that the control unit is configured, in the presence of a turned-on condition of the road vehicle and when the internal combustion engine is off, to activate the electronic DC-DC power converter so as to transfer power to be at least partially supplied to the electric starter motor from the high-voltage electric circuit to the low-voltage electric circuit only in case of the cold-start condition of the internal combustion engine.