2020 AUDI A8 brakes

4N0012721BD
Trailer towing

Trailer towing
Driving with a trailer
General information
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
151
>

4N0012721BD
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: reduce the speed and use
the
recuperation braking effect > page 118 to re-
lieve 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.

ZA\ 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.

153

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.

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.


C) 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 braking effect of re-
cuperation > page 118. This reduces the
load on the brakes.
@ Tips
The brake lights turn on when the brakes are
applied automatically.
166
Switching the system on
Applies to: vehicles with cruise control system

BFV-0220



Fig. 123 Lever: switching on the cruise control system
Requirement: The ignition must be switched on.
> To switch the system on, pull the lever toward
you to position @.
The Ga or 8) indicator light and the corre-
sponding message will appear in the instrument
cluster.

A WARNING
If the brakes are malfunctioning (for example,
overheating) while the cruise control system
is switched on, it may shut off automatically.
Preselecting or activating a cruise control
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 @)/C)
=> page 166, fig. 123.
> To activate the cruise control speed, pull the
lever
toward position @ while driving, or
> 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 Gs or kl indicator light in the instrument
cluster.
An additional indicator appears in the head-up
display*.

4N0012721BD
Driver assistance

Changing the cruise control speed
Applies to: vehicles with cruise control system
> To increase or decrease the cruise control speed
in small increments, tap the lever up to the
first level toward @)/C) > page 166, fig. 123.
> To increase or decrease the cruise control speed
in larger increments, tap the lever up to the
second level toward ()/C).
> 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 activated.
Overriding
> To temporarily override the cruise control
speed, press the accelerator pedal.
> Once you release the accelerator pedal, the sys-
tem will adjust back to the stored cruise control
speed.
If you override the cruise control system for a
long period of time, the cruise control system
will be deactivated. The ICRUISE| or 88) indicator
light will be displayed and the cruise control
speed will be saved.
Deactivating
> To deactivate the cruise control speed, press
the lever toward (2) (not locked into place)
=> page 166, fig. 123.
> Press the brake pedal.

ZA WARNING
Resting your foot on the accelerator pedal
could override the cruise control. This will pre-
vent braking interventions by the system.

Seem Leal
Applies to: vehicles with cruise control system
When you switch the system off completely, the
cruise control speed will be deleted.
Requirement: the system must be switched on.
> To switch the system off, press the lever toward
@ (locked into place) > page 166, fig. 123, or
> Switch the ignition off.
Applies to: vehicles with cruise control system
Gk / 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.
When you remove your foot from the accelerator
pedal, efficiency assist controls downhill mode
with recuperation, depending on the situation.
Adjusting the efficiency assist
You can adjust efficiency assist functions individ-
ually. The settings depend on the vehicle equip-
ment.
— Predictive messages > page 168.
— Predictive control > page 169.
— Accelerator pedal feedback > page 115.
— Interactive accelerator > page 115.
167

Driver assistance

sensors > page 156, fig. 117 and try to turn on
the systems again later.
If the malfunction remains, drive to an author-
ized Audi dealer or authorized Audi Service Facili-
ty immediately to have the malfunction correct-
ed.

ZA\ WARNING
— Follow the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 154.
— Pay attention to traffic and the area around
your vehicle when predictive control is
switched on. The driver is always responsible
for assessing the traffic situation.
— The system does not consider “right of way”
rules and does not respond to traffic lights,
so lack of driver attention in these situations
can increase the risk of an accident.
— The speed when driving through curves may
be different from what you as a driver would
do or may not be suitable for the weather
and road conditions. If necessary, apply the
brakes and reduce the selected speed to be
maintained in the Adjustment to curves
along route setting to reduce the risk of an
accident.

G) Tips
— Predictive control can exceed or drop below
the maximum permitted speed. The driver
is responsible for adhering to the permitted
speed limit.
— The traffic signs on the road always take pri-
ority over the display. The driver is always
responsible for adhering to the regulations
applicable in the country where the vehicle
is being operated.
—If a speed limit is detected, the marking @
of the set speed limit will be adjusted even
if the adaptive cruise assist is not actively
regulating.
— Control by the system depends on which
adaptive cruise assist driving program is set
or on the selected Audi drive select* mode.

YD In certain countries
170
— After switching on the ignition and first
driving onto a freeway or similar road with-
out a speed limit, the system will regulate
the speed to 80 mph (130 km/h). Then
the system adjusts to the last speed set by
the driver.
— There is no adaptation to speed limits when
driving through highway interchanges and
when driving on or off the expressway.
— The system can fail to provide control or the
control may be faulty if the values from the
camera-based traffic sign recognition* are
incorrect or the navigation system map data
is outdated.
— When route guidance is switched on, the
system adapts to the route provided by the
navigation system. Driving without route
guidance or leaving a route can result in
faulty control.
— Certain settings are stored automatically in
the active personal profile.
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 and distance control assists the driver in
controlling the speed and the set distance to the
vehicle driving ahead. If the system detects a ve-
hicle driving ahead, the adaptive cruise assist can
brake and accelerate your vehicle within the lim-
its of the system. On open roads with no traffic, it
functions like a cruise control system. The stored
speed is maintained. When approaching a vehicle
driving ahead, the adaptive cruise assist auto-
matically brakes to match that vehicle's speed
and then maintains the set distance as much as
possible. As soon as the system does not detect a
vehicle driving ahead, adaptive cruise assist ac-
celerates up to the set speed.

4N0012721BD
Driver assistance

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 174, 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
and road conditions > page 169, Predictive con-
trol.

Follow the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 154.


For an explanation on conformity with the
FCC regulations in the United States and the
Industry Canada regulations, see > page 339.
Applies to: vehicles with adaptive cruise assist

B8V-0630


Fig. 125 Example: vehicle changing lanes and stationary
vehicle



Fig. 126 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.
— Ifa vehicle that was already detected @ turns
or changes lanes, the adaptive cruise assist will
react to the vehicle ahead of it @).
— When driving into a curve > fig. 126 and out of
a curve, the adaptive cruise assist may react to
a vehicle in the adjacent lane and apply the
brakes. You can override the system by pressing
the accelerator pedal briefly.
— The adaptive cruise assist works with the vari-
ous sensors and cameras in the vehicle.
Vehicles can only be detected once they are
within the area and range covered by the sen-
sors > page 155, fig. 115.
— 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 adaptive cruise assist does not react toa
stationary vehicle in the same lane if the sys-
tem expects that you can easily drive around
the stationary vehicle by turning the steering
wheel.
— The adaptive cruise assist may not react to sta-
tionary obstacles, such as the end of a traffic
jam, especially at high speeds.
— The adaptive cruise assist 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.
171

Driver assistance

— The adaptive cruise assist does not respond to
people, animals, or objects that are crossing or
approaching from the opposite direction.

Z\ WARNING
Follow the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 154.
Display overview
Applies to: vehicles with adaptive cruise assist

3] S|
me Ny Iz G3

Fig. 128 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)
172
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
Detected vehicle driving ahead
Set target distance
If you fall below the set distance, the dis-
tance bars turn red from the bottom upward.
Your vehicle
©®
CO©®
Availability of lane departure warning
= page 180 and lane guidance
© Lane guidance for adaptive cruise assist is ac-
tive 1 or not active
Indicator lights
A - The speed/distance control is active. No
vehicles were detected ahead. The stored speed
is maintained.
Ba - The speed/distance control is active. A vehi-
cle was detected ahead. The adaptive cruise as-
sist controls the speed and distance from the ve-
hicle 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.
BS - 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.
aA - The automatic braking is not enough to
maintain a sufficient distance to a vehicle driving
ahead. You must intervene > page 177, Driver in-
tervention request.
& This indicator light appears if steering activity
is no longer detected. Always keep your hands on
the steering wheel so you can be ready to steer at
any time. The indicator light will also turn off, for
example if the steering power from the system is
not sufficient and adaptive cruise assist is can-
celed > page 175.

4N0012721BD
Driver assistance

— The driver's hands are not on the steering
wheel
Steering intervention request
If no steering activity is detected or the steering
power is not sufficient, the driver steering inter-
vention request will alert the driver using audio
and visual signals. Take over the steering and
keep your hands on the steering wheel so that
you will be ready to steer at any time. The system
will become inactive after a short time and will
only be active again later.
If the driver does not take over steering, adaptive
cruise assist will be canceled. If the vehicle is
equipped with emergency assist and it is ready to
function, it will be activated > page 190.

ZA WARNING
Follow the safety precautions and note the
limits of the assist systems, sensors, and
cameras > page 154.

@ Tips
— Always keep your hands on the steering
wheel. The driver is always responsible for
adhering to the regulations applicable in
the country where the vehicle is being oper-
ated.
— It is recommended to only switch on lane
guidance on well-constructed roads.
— Certain settings are stored automatically in
the active personal profile.
—The & fig. 131 button switches lane guid-
ance availability and the lane departure
warning on or off simultaneously, if lane
guidance is preset in the adaptive cruise as-
sist settings.
Setting the distance
Applies to: vehicles with adaptive cruise assist

B4M-0234



Fig. 132 Operating lever: setting the distance
If you adjust the speed, you must also change the
time gap to the vehicle driving ahead. The higher
the speed, the greater the distance that is need-
ed.
> Tap the rocker switch to display the distance
that is currently set.
> To increase or decrease the distance in incre-
ments, tap the switch again toward G) or ().
The newly-set distance will be shown briefly, for
example with the indicator light. In the Driv-
er assistance display, a graphic display is shown
instead of the indicator lights > page 172,
fig. 128. The display matches the functions of
the indicator lights.
When approaching a vehicle driving ahead, the
adaptive cruise assist brakes to the set speed and
then maintains the set distance. If the vehicle
driving ahead accelerates, then the adaptive
cruise assist will also accelerate up to the speed
that you have set.
The following distances can be set:
175