标题：4motion
4MOTION系统
4Motion系统是大众车系中普遍采用的系统（类似于奥迪的Quattro），它是将动力根据前后50:50（正常的路面上可能不采用50:50的分配方式，而是90:10或者其他分配方式）的形式分配给前，后桥，并在必要时依靠系统会把百分之百的驱动力是附在一个车轮的动力上。  动力分配
这就说明系统可以将0%到100%的动力输出到前或者后轴。所以在不同的路况下，它将随时调整分配个前后轴的动力比例，以适应各种路况。 
4Motion技术核心
Haldex中央差速器
Haldex中央差速器至今已发展为多片离合差速控制系统，通过机械装置与电控液压系统共同作用达到智能分配扭矩的目的。这个多片离合器依车型不同而布置在不同的位置，有的靠近后桥差速器，有的类似于奥迪的方法与变速器融为一体。
其原理类似于手动挡汽车的离合器，只不过摩擦件间的压紧力由弹簧力变成油液压力。基本结构为：输入轴末端通过花键与离合器片径向固定；输出轴与壳体铸为一体，壳体内侧也安装了多片离合器片。扭矩的分配便是通过油压对离合器片的作用来实现，油压的高低决定了分配扭矩的大小，而油压则是通过ECU控制电磁阀产生的。有了ECU，至于何时何地分配多少扭矩到各个车轮，自然也就变得简单。[1]
英文参考
(ENGLISH VERSION):　It's a high tech about full wheels driving of VOLKSWAGEN
ORIGINAL EDITION :
4Motion system will be a driving force in accordance with the before and after the form of 50:50 allocated to the before and after the bridge, and when necessary to rely on System 4Motion put 100 percent of the driving forces are attached to a wheel of the above, even if three wheels, all in a spin state, theoretically, the Touareg or Cayenne can be quiet out of the woods. Because of the torque output can be differential inside the clutch disc to set up, so can be controlled 4Motion assigned to the front axle and rear axle ratio of the power. 
Theoretically, it can be output to a single axis of power control from 0-100%, or 50:50 ratio of output power. Basically, the driver can not be aware of its work. When a vehicle traveling in the urban areas when the normal road, basically the same as before and after the shaft rotational speed, the computer will be 90% of the power output to the front, leaving only 10% to the rear axle. Throughout the journey the driver may have noticed that the process is the only 4Motion system with the public at no matter what road vehicle conditions can be easily demonstrated, there is no sense unexpected. Express start to speed up the time, 4motion Constant all-wheel drive when the system will adjust the output as the best model to exert the strongest grip.Once in normal driving conditions, driving wheel is no longer available to the threat, the system again and return to normal mode settings. Phaeton as long as there is a tire has grip, the vehicle can safely move the road, so driving safety, not in general the traditional rear-wheel drive accessible. 4Motion four-wheel-drive a new generation of real-time in 1998 compared to the first generation of products have advanced much. Advanced electronic control system response to commands faster and more stable, while oil replacement time of the 3000 kilometers from the previous 6000 kilometers into.Also, after the electron differential directly on axis, reducing the system size, more compact. Including the Passat, including a number of public cars are examples of the use of 4Motion. There is no doubt that we all know that four-wheel-drive in the wet muddy road above absolute performance is better than an ordinary two-drive vehicles, and now even in the dry road, the day the more sophisticated real-time four-wheel-drive has gradually at traffic performance, control of the are beginning to challenge from other pre-and post-drive vehicles, and it was turning a corner at the time of stability and high active safety and access to manufacturers and customers of all ages.