A front-and-rear wheel drive vehicle includes an engine driving a pair of front wheels and rear wheels, and a field-control motor driving the other pair of front wheels and rear wheels. Also included is a speed sensor detecting the rotating speed of the other pair of wheels, and a control unit controlling...http://www.google.fr/patents/US6349782?utm_source=gb-gplus-shareBrevet US6349782 - Front-and-rear wheel drive vehicle
