Specifications

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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 goes to the front axle,
60% to the
rear. The benefit
is better traction during accelera-
tion
and improved safety due to exceptional 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 more feel for the
road and thus increased safety.
The optional quattro® with sports differential
further reinforces this unmistakeable quattro
feeling. Vehicles tend to experience understeer
when steering
or driving into corners. This is a nor-
mal physical
process: A moving object opposes a
change in direction. The
elastic tyres and the
suspension mounts
tense up until the new direc-
tion 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 differen-
tial on the rear
axle, the tendency to understeer
is largely counteracted. This is because the quat-
tro rear axle differential has been extended left
and right by a clutch system with two gear lev-
els. They ensure
that the individual wheels on
the rear axle receive different levels of torque.
The clutches are
activated by an electro-hydrau-
lic actuator. Depending, for example, on
the
steering angle, lateral acceleration, yaw
angle
and driving speed, the system calculates the
right distribution of wheel torque for any driv-
ing situation. In this way the
power is specifical-
ly channelled to the outer rear wheel, when
steering or accelerating into
a corner. The ef-
fect: the vehicle is effectively
pressed into the
corner and follows the angle
of the front wheels.
The variable left and right
driving forces also help
stabilise the steering and the usual steering cor-
rections are hardly necessary.
30
years of quattro®
quattro® with sports differential
continuously varies the amount of
driving force distributed to each
rear wheel and ensures high corner-
ing agility and impressive driving
dynamics.
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34
S34_A7_Fas09_Bild 34 07.09.10 10:41
quattro®/quattro® with sports differential
With quattro®, we have created one of
the best all-wheel drive systems in the world.
Of course, that was not good enough for us.
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