Specifications

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quattro® with sports differential
With quattro®, we have invented one of
the best all-wheel drive systems in the world.
Of course, that was not enough for us.
quattro® is a permanent all-wheel drive system.
If the wheels on one axle of the vehicle lose grip
on the road and threaten to spin, then the power
is transferred to the other axle – automatically
and permanently distributed through the centre
differential. The basic distribution is 40 : 60 –
40 % of the power comes from the front axle,
60 % from the rear axle. The benefit is better
traction during acceleration and improved
safety due to improved grip. So much for the
technology. But what makes quattro unique is
really the driving feel. “As if you are stuck to
the road,” some customers say. We put it like
this: quattro gives you a better feel for the road –
and with more safety.
The quattro® with sports differential further
reinforces this unmistakeable quattro feeling.
Vehicles tend to experience understeer when
steering or driving into corners. This is a normal
physical process: a moving object opposes a
change in direction. The elastic tyres and the
suspension mounts tense up until the new
direction has been adopted. When accelerating
into a corner, the load on the front axle is
reduced and it therefore transfers less lateral
force to the tyres – the vehicle understeers.
With the sports differential on the rear axle, this
tendency has been significantly counteracted.
That’s because the quattro rear axle differential
has been extended left and right by a clutch
system with two gear levels. They ensure that
the individual wheels on the rear axle receive
different levels of torque.
The clutches are activated by an electrohydraulic
actuator. Depending, for example, on the
steering angle, lateral acceleration, yaw angle
and driving speed, the system calculates the
right distribution of wheel torque. In this way the
power is specifically channelled to the outer rear
wheel when steering or accelerating into a corner.
The sports differential has a reaction time of less
than 100 milliseconds and is therefore faster
than the ESP. And while ESP can only take effect
once there is a certain difference between the
steering angle and the rotational movement of
the vehicle, the sports differential influences the
dynamics of the vehicle before this occurs.
The fuel consumption and CO₂ emission figures can be found on page 50.
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