Motor vehicle with insertable four-wheel drive

An insertable four-wheel drive motor vehicle, comprising:

• an engine presenting a crankshaft;
• a pair of main driving wheels permanently connected to the crankshaft by interposition of a gearbox provided with at least one first clutch;
• a pair of secondary driving wheels;
• an insertable transmission system, which is adapted to connect the crankshaft also to the secondary driving wheels and comprises a second controllable clutch for transmitting a variable torque from zero to a maximum value;
• the second clutch on one end is mechanically connected to the crankshaft upstream of the gearbox and on another end is mechanically connected to the secondary driving wheels;
• an electronic control unit for controlling the insertable transmission system by controlling actuation of the second clutch;
• and
• a number of first sensors, which are connected to the electronic control unit and detect a number of dynamic parameters of the motor vehicle,
• wherein the electronic control unit determines a percentage of motive torque to be transmitted to the secondary driving wheels according to the dynamic parameters of the motor vehicle detected by the first sensors.