Volvo's All-Wheel-Drive Functions:   

The level of brightness of the red color is an indication of the amount of power applied to each wheel.  

   
When driving normally, most of the power is distributed to the front wheels.  

  
If the front wheels start to spin, power is transferred to the rear wheels.  

If one of a pair of wheels starts to spin, the viscous coupling, in combination with the TRACS system on the front axle, distributes more power to the wheel with the best grip.  

When the driver brakes, the freewheel unit disengages the drive to the rear wheels  to produce greater braking stability.

AWD does for traction what ABS does for braking. It Increases control and  predictability. Seamless in application, unnoticeable under normal driving conditions and higher efficient, Volvo's All-Wheel-Drive system offers full time availability of power to all four wheels for optimum traction in all driving conditions. 

Volvo's AWD system requires no driver input and is designed to maximize traction by continuously monitoring wheel slippage and smoothly transferring power to the tires with the best grip. 

In Volvo's AWD system, a viscous coupling is installed on the drive shaft at the point where power distribution is split. The coupling transmits no power to the rear wheels unless the situation demands it. The coupling itself is a series of metal plates surrounded by silicon fluid. In the event that the front wheels spin faster than the rear wheels, friction inside the coupling grows and the silicon fluid inside becomes more viscous. 

The viscous fluid now begins to spin the plate on the rear of the coupling that leads to the rear wheels. Power now begins to transfer to the rear wheels. Even if the front wheels lose significant grip, the power transfers to the rear wheel 
to keep the vehicle going in a straight line. The system can more effortlessly from 95 percent front/5 percent rear to 5 percent front/95 percent rear. Volvo's AWD system is operational in reverse also. 

In the Volvo AWD system the viscous coupling contains a freewheeling mechanism that disconnects the power to the rear wheels during braking. This allows the ABS to be functional as a 4-wheel system. 

Volvo design and All-Wheel-Drive 
Integrating the two products produces a unique and superior automobile. AWD takes quantities upon which Volvo has built it's reputation and enhances them. Responsive and predictable handling, all-season reliability, advanced safety design, sure-footed road holding... with AWD it's a Volvo, only more so.

TOP     TOP     TOP     TOP     TOP