2021 AUDI A8 brake

4N0012721BF
Trailer towing

Trailer towing
Driving with a trailer
eT e e eeu)
Your vehicle is primarily intended for transport-
ing people and luggage. However, if you drive
with a trailer, follow the technical requirements,
the operation and driving tips, and the legal reg-
ulations.
Driving with a trailer affects the vehicle's energy
usage, performance, and wear. It also requires
higher concentration from the driver.

Z\ WARNING
Do not transport any people in a trailer due to
the risk of fatal injury.
Technical requirements
Trailer hitch

Only use a trailer hitch with a removable ball
hitch mount and ball hitch. The trailer hitch must
be permitted for the vehicle, the trailer and the
permitted total weight of the trailer being
pulled. Above all, it must be securely and safely
attached to the vehicle trailer.
Never mount a trailer hitch on the bumper. The
trailer hitch must be mounted in a way that does
not impair the function of the bumper. Do not
make any changes to the exhaust system and the
brake system.
Check regularly if the trailer hitch is securely
mounted. Always follow the instructions given by
the trailer hitch manufacturer.
Trailer brakes
If the trailer has its own brake system, then fol-
low the manufacturer specifications. However,
the brake system on the trailer must never be
connected to the vehicle brake system.
Engine cooling system
Driving with a trailer means a higher load on the
engine and the cooling system. The cooling sys-
tem must be designed for additional load and
contain enough coolant > @®.
CG) Note
Longer inclines cannot be driven without a
suitable cooling system, especially if the out-
side temperatures are high. Otherwise, this
increases the risk of engine damage.
Operating instructions
Towing capacity
Your vehicle can only be operated with class 1 or
class 2 trailers.
Load distribution
Poor cargo load and distribution can negatively
impact vehicle handling. Load the trailer based
on the following criteria as much as possible:
— Store objects in the vehicle luggage compart-
ment, if possible. The vehicle should always
carry the heaviest possible load and the trailer
should have the lightest possible load.
— Distribute the load in the trailer so that the
heavy objects are as close to the axle as possi-
ble.
— Secure objects so that they do not slide.
— Utilize the maximum permitted tongue weight
if possible.
Tires
Set the tire pressure on your vehicle for a “full
load”; see the tire pressure sticker > page 299. If
necessary, also adjust the tire pressure on the
trailer according to the manufacturer's specifica-
tions.
The trailer and the vehicle should be equipped
with winter tires when driving in winter tempera-
tures.
Outside mirrors
If you cannot see the traffic behind the trailer
with the standard exterior mirrors, then you
must attach additional exterior mirrors. Adjust
them so you have a sufficient visibility behind
you.
Exterior lighting
Follow the legal regulations for lighting on your
trailer that are applicable in the country where
147
>

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Trailer towing

Hill
When you start driving uphill or downhill, trailers
may tilt or sway sooner than when driving ona
level surface. If small swaying movements have
already occurred, you can stabilize the trailer by
firmly braking immediately. Never attempt to
“straighten out” the trailer by accelerating.
Conventional drive system: Downshift before
driving on hills to utilize the engine braking ef-
fect SA.
Plug-in hybrid drive system: Reduce the speed
and use the recuperation braking effect
=> page 114 to relieve the brakes > A.
Brakes
When using a trailer with overrun brakes, first
brake gently then quickly. This reduces the risk of
jerking while braking if the trailer wheels lock up.
Engine coolant temperature
Pay attention specifically to the coolant tempera-
ture display when there are high outside temper-
atures, and when driving on long inclines
=> page 14. Shift to a higher gear in a timely man-
ner.

Z\ WARNING
Constant braking causes the brakes to over-
heat and can substantially reduce braking per-
formance, increase braking distance, or cause
complete failure of the brake system.

149

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Driver assistance

Driver assistance
Cruise control system
Applies to: vehicles with cruise control system
The cruise control system assists the driver in
maintaining a constant speed above approxi-
mately 15 mph (20 km/h). The system maintains
the desired speed by braking and accelerating.
Switching the system on
Applies to: vehicles with cruise control system


ZA WARNING
— Always pay attention to the traffic around
your vehicle when the cruise control system
is in operation. As the driver, you are always
responsible for controlling your vehicle
speed and the distance between your vehicle
and
other vehicles.
— For safety reasons, cruise control should not
be used in the city, in stop-and-go traffic, on
winding roads, and when road conditions are
poor (such as ice, fog, gravel, heavy rain,
and conditions that could lead to hydroplan-
ing), because this increases the risk of an ac-
cident.
— Switch the cruise control off temporarily
when driving in turning lanes, highway exits,
or in construction zones.
—To reduce the risk of an accident, you should
only resume the stored speed if it is suitable
for the current traffic conditions.
BFV-0220



() Note
— Conventional drive system:Before driving
downhill a long distance on a steep hill, de-
crease your speed and select a lower gear.
This makes use of the engine braking effect
and reduces the load placed on the brakes.
— Plug-in hybrid drive: Before driving downhill
a long distance on a steep hill, decrease
your speed and use the recuperation braking
effect > page 114. This reduces the load on
the brakes.
@ Tips
The brake lights turn on when the brakes are
applied automatically.


Fig. 116 Operating lever: switching the system on
Requirement: the ignition must be switched on.
> To switch the system on, pull the lever toward
you to position ©.
The Gia or i$) indicator light and the corre-
sponding message will appear in the instrument
cluster.

ZA\ WARNING
If the brakes are malfunctioning (for example,
overheating) while the cruise control system
is switched on, the regulating functions may


shut off automatically.


Preselecting or activating a cruise con
speed
Applies to: vehicles with cruise control system
When the vehicle is stationary, you can preselect
the cruise control speed or activate the speed
while driving.
Requirement: the system must be switched on.
> To preselect a cruise control speed when the ve-
hicle is stationary, tap the lever toward @)/G)
=> page 163, fig. 116.
> To activate the cruise control speed, pull the
lever
toward position @ while driving.
> To set the current driving speed as the cruise
control speed, press the button @) on the lever.
The active cruise control speed is indicated with
the Gg or kl indicator light in the instrument
cluster.
163
>

Driver assistance

An additional indicator will appear in the head-up
display*.
Changing the cruise control speed
Applies to: vehicles with cruise control system
Requirement: the system must be switched on.
> To increase or decrease the cruise control speed
in small increments, tap the lever up to the
first level toward @)/G) 9 page 163, fig. 116.
> To increase or decrease the cruise control speed
in larger increments, tap the lever up to the
second level toward @)/G).
> To increase or decrease the cruise control speed
continuously, tap and hold the lever at the first
or second level toward @)/G).
Overriding or deactivating the cruise
control speed
Applies to: vehicles with cruise control system
You can override or deactivate the cruise control
system. When you deactivate the system, your
cruise control speed will be stored and you can
resume that speed.
Requirement: the system must be switched on
and the regulated speed must be activated.
Overriding
> To temporarily override the cruise control
speed, press the accelerator pedal.
> To resume the stored regulated speed, remove
your foot from the accelerator pedal.
If you override the cruise control system for a
long period of time, the cruise control system
will be deactivated. The [Ud or [RM indicator
light will be displayed and the cruise control
speed will be saved.
Deactivating
> To deactivate the cruise control speed, press
the lever toward @) (not locked into place)
=> page 163, fig. 116, or
> Press the brake pedal.
164

ZA WARNING
Resting your foot on the accelerator pedal
could override the cruise control. This will pre-
vent braking interventions by the system.
See me Lai
Applies to: vehicles with cruise control system

When you switch the system off, the cruise con-
trol speed will be erased.
Requirement: the system must be switched on.
> To switch the system off, press the lever toward
@ (locked into place) > page 163, fig. 116, or
> Switch the ignition off.
Applies to: vehicles with cruise control system
Gir / 3) Speed control system: currently un-
available. See owner's manual
If the indicator light turns on and this message
appears, the cruise control system has been deac-
tivated. There is a temporary malfunction, for ex-
ample the brakes are overheating. Switch the
cruise control system on again later.
Efficiency assist
Applies to: vehicles with efficiency assist
Efficiency assist can assist the driver with predic-
tive information in order to reduce fuel consump-
tion. Depending on vehicle equipment, the sys-
tem may access data from the navigation system,
the camera behind the windshield, and the radar
sensors.
Adjusting the efficiency assist
You can adjust efficiency assist functions individ-
ually. The settings depend on the vehicle equip-
ment.
— Accelerator pedal feedback > page 111.
— Interactive accelerator > page 111.
— Predictive messages > page 165.
— Predictive control > page 174, Adjusting the
adaptive cruise assist.

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Driver assistance

Situation symbols
Depending on vehicle equipment, the following
symbols may be shown. The symbols indicate the
situation to which the efficiency assist is respond-
ing.
Some symbols only appear if Predictive messag-
es are switched on, and some symbols only ap-
pear if Predictive control is switched on and
adaptive cruise assist* is active.


Description
Slow down
(predictive messages only)
Speed limit
(example)
Speed limit removed
Exit ahead
Intersection ahead
Traffic circle ahead
(predictive control only) If the indica-
tor light turns on in green and red, it
is indicating that there is a difference
between the speed limit and the set
speed.


ZA WARNING
— Observe the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 150.
—Incertain situations, the recuperation may
brake proactively. However, the recuperation
braking effect is limited. Always be ready to

brake to reduce the risk of an accident.

@ Tips
— The functions depend on the navigation da-
ta* being up-to-date and correct identifica-
tion by the traffic sign recognition*.
— The system only detects traffic signs that
specify a speed limit.
— The display in the instrument cluster is
based on the units of measurement used for
speed in the country where the vehicle is be-
ing operated. As a result, a display of 50 in
the instrument cluster can mean either mph
or km/h, depending on the country.
— Except for the road network, which is re-
corded in the navigation system’s map infor-
mation, certain functions may not be availa-
ble.
Predictive messages
Applies to: vehicles with efficiency assist
The symbol BS appears in the instrument cluster
display if efficiency assist recommends removing
your foot from the accelerator pedal.
Additional symbols that indicate the situation to
which the efficiency assist is reacting are shown
in the Driver assistance display > page 165.
Requirements
— The cruise control system* or the adaptive
cruise assist* controls must not be active.
— The vehicle speed must be at least 20 mph
(30 km/h).
— The remaining distance until the situation is
reached must be large enough to allow the sys-
tem to react to the situation.
Switching Predictive messages on or off
Applies to: MMI: Select on the home screen: VE-
HICLE > Charging & Efficiency > Efficiency assist
> Predictive messages.

ZA\ WARNING
— Observe the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 150.
— Pay attention to traffic and the area around
your vehicle when efficiency assist is switch-
ed on. The driver is always responsible for
assessing the traffic situation.
G) Tips
— The traffic signs on the road always take pri-
ority over the display. The driver is always
responsible for adhering to the regulations

165

Driver assistance

applicable in the country where the vehicle
is being operated.
— When a route is planned using the naviga-
tion system*, then system displays messag-
es based on an assumed route. Without
route guidance, the system displays mes-
sages based on an assumed route.
— The wording of the message may vary de-
pending on the selected Audi drive select*
mode and the selected gear. No messages
are displayed when in the "S" driving pro-
gram.
Adaptive cruise assist
General information
Applies to: vehicles with adaptive cruise assist

Depending on the vehicle equipment, the adap-
tive cruise assist may consist of the following
functions:
Within the limits of the system, the adaptive
speed assist assists the driver in controlling the
speed and the set distance to the vehicle driving
ahead. If the system detects a vehicle driving
ahead, the adaptive speed assist can brake and
accelerate your vehicle within the limits of the
system. On open roads with no traffic, it Func-
tions like a cruise control system. The stored
speed is maintained. When approaching a vehicle
driving ahead, the adaptive speed assist auto-
matically brakes to match that vehicle's speed
and then maintains the set distance as much as
possible. Once the system does not detect a vehi-
cle driving ahead, adaptive speed assist will ac-
celerate up to the set speed.
The additional lane guidance assists the driver
with corrective steering in order to stay in the
lane. You can adjust if the adaptive cruise assist
will provide support with lane guidance
=> page 169, Switching lane guidance on and off.
In stop-and-go traffic and in traffic jams, the ve-
hicle may brake to a full stop and then may also
start driving again automatically under certain
conditions.
Applies to: vehicles with efficiency assist: Predic-
tive control can adjust the speed based on traffic
166

and road conditions > page 170, Predictive con-
trol.

ZA WARNING
Observe the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 150.
@ Tips
The system complies with United States FCC
regulations and ISED regulations > page 341.


mitations
Applies to: vehicles with adaptive cruise assist
B4m-0093

Fig. 117 Example: driving into a curve
In some situations, the adaptive cruise assist
function is limited and you must assume control
of the vehicle when necessary, for example by ap-
plying the brakes.
— When driving into a curve > fig. 117 and out of
a curve, the system may react to a vehicle in the
neighboring lane and apply the brakes. You can
override the system by pressing the accelerator
pedal briefly.
— The system works with the various sensors and
cameras in the vehicle. Vehicles can only be de-
tected once they are within the area and range
covered by the sensors > page 151, fig. 108.
— When driving around tight curves, a vehicle
driving ahead that was previously detected may
no longer be detected, and the adaptive cruise
assist may accelerate unexpectedly.
— The system does not react to a stationary vehi-
cle in the same lane if it expects that you can
easily drive around the stationary vehicle by
turning the steering wheel.

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Driver assistance

— The system cannot react to stationary objects,
such as vehicles at the end of a traffic jam, es-
pecially when traveling at high speeds.
— The system has a limited ability to detect
vehicles that are a short distance ahead, off to
the side of your vehicle, or moving into your
lane.
— Objects that are difficult to detect, such as mo-
torcycles, vehicles with high ground clearance,
or vehicles with an overhanging load, may be
detected late or not detected at all.
— The system does not respond to people, ani-
mals, or objects that are crossing or approach-
ing from the opposite direction.

ZA\ WARNING
Observe the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 150.


Display overview
Applies to: vehicles with adaptive cruise assist
RAZ-0205,

Fig. 119 Instrument cluster: driver assistance display
Indicator lights and messages in the speedome-
ter @ - @ inform you about the driving situation
and the settings. In the Driver assistance display
@ - @, you can find more detailed information
about the system. The displays depend on the
country and equipment.
Display in the speedometer
The display in the speedometer is not available in
all layouts*.
@ Marking for the set speed
@ Current vehicle speed
@® Available speed range for adaptive cruise as-
sist (example)
Image in the Driver assistance display
The display only appears when the Driver assis-
tance display is open in the on-board computer
=> page 16.
Messages and settings
Your vehicle
Detected vehicle driving ahead
Messages and settings
Set target distance
If you fall below the set distance, the dis-
tance bars turn red from the bottom upward.
Lane departure warning availability
O®
©O©QOOO®
Availability of lane guidance for adaptive
cruise assist
Indicator lights
Ba - The speed/distance control is active. No
vehicles were detected ahead. The stored speed
is maintained.
aA - The speed/distance control is active. A vehi-
cle was detected ahead. The system controls the
speed and distance from the vehicle driving
ahead, and accelerates and brakes automatically.
A - The speed/distance control is active but the
vehicle is not ready to drive. A vehicle was de-
tected ahead. Your vehicle is stationary and will
not start driving automatically.
B - The speed/distance control is active but the
vehicle is not ready to drive. No vehicles were de-
tected ahead. Your vehicle is stationary and will
not start driving automatically.
B.- The automatic braking is not enough to
maintain a sufficient distance from a vehicle driv-
ing ahead. You must intervene > page 174, Driv-
er intervention request.
w- Lane guidance is active.
167

Driver assistance

Dp 4 — Lane guidance is switched on but not active.
> 4 - The limits of the system have been reached.
Take over steering.
A / en) - The indicator light turns on if the
steering intervention request is providing a warn-
ing. Always keep your hands on the steering
wheel so you can be ready to steer at any time
=>page 170.

Z\ WARNING
Observe the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 150.
Using adaptive cruise assist
Applies to: vehicles with adaptive cruise assist


RAZ-0096


Fig. 120 Lever: using adaptive cruise assist

B4M-0232


2
zt
5
©
Fig. 121 Operating lever: changing the speed
Switching on
> To switch on the adaptive cruise assist, pull the
lever up to position @ until it engages.
Storing the speed and activating regulation
If you have switched the system on, you can set
the current speed as the “regulated speed” and
activate regulation:
168

> Press the [SET] button @). The set speed is indi-
cated with a marking in the speedometer (@)
= page 167, fig. 118 and shown in the instru-
ment cluster > /\.
> To save the speed while the vehicle is station-
ary, also hold the brake pedal down.

You can set any speed between 15 mph
(20 km/h) and the maximum possible speed
range @) > page 167, fig. 118.
Pausing cruise control
The control can be stopped at any time:
> While driving or when the vehicle is stationary:
Press the lever away from you in the direction
of the arrow. Or
> While driving: Press the brake pedal.
The A indicator light turns off.
Resuming regulation
The previously set speed can be resumed at any
time after a pause.
> To resume cruise control while driving, pull the
lever
toward you in the direction of the arrow.
> To resume cruise control when stationary, pull
the lever toward you in the direction of the ar-
row while pressing the brake pedal.
Changing the speed
> To increase or decrease the set speed in smaller
increments, briefly tap the lever toward () or
© to the first level.
> To increase or decrease the set speed in larger
increments, briefly tap the lever toward @) or
© to the second level.
> To increase or decrease the set speed quickly,
hold the lever toward G) or () until the mark-
ing in the speedometer @) > page 167, fig. 118
has reached the desired speed.
Preselecting a speed
You can also preselect the speed when adaptive
cruise assist is not active by moving the lever in
the desired direction @)/©). Activate the previ-
ously selected speed by pulling the lever toward
you in the direction of the arrow.