4motion four-wheel drive system full-time four-wheel drive, 4motion is the trademark of Volkswagen four-wheel drive technology, and it is also a full-time four-wheel drive system widely used by Volkswagen. 4motion is suitable for a horizontal platform with a high degree of electrical control. Its working principle is: friction braking is realized by pressing the clutch plate, so that power is distributed to the non-slip axle. Full-time four-wheel drive distributes the driving force to the four tires through the flexibly connected central differential, and then through the independent differential of the front axle and the rear axle. Different from the pure mechanical differential lock, the differential of full-time four-wheel drive can be adhesive coupling or multi-clutch, but the same thing is that a speed difference can be allowed between the front and rear wheels and the left and right wheels. Million car purchase subsidy