traction control AUDI S8 2012 Owners Manual

Intelligent technology Notice about data
recorded by vehicle
control modules
Your vehicle is not equipped with an Event Da­
ta Recorder (EDR), installed by some manu­
facturers for the express purpose of capturing
data for retrieval after an accident or crash
event. EDR's are sometimes called "crash re­
corders".
Some state laws restrict the retr ieval or down­
loading of data stored by EDR's that were in­
stalled in a vehicle for the express purpose of
retrieving data after an accident or crash
event without the owner's consent.
Although your vehicle is not equipped with an
EDR, it is equipped with a number of electron­
ic control modules for various vehicle systems
such as, for examp le, engine function, emis­
sion control, as well as for the airbags and
safety belts.
These electronic control modules also record
vehicle-related data during norma l vehicle op­
eration for diagnostic and repair purposes.
The recording capacity of the electronic con­
trol modules is limited to data (no sound is re­
corded) and only a small amount of data is ac­
tually recorded over a very limited period of
time and stored when a system fault or other
condition is sensed by a control unit. Some of
the data then stored may relate to vehicle
speed, direction, braking as we ll as restraint
system use and performance in the event of a
crash or other condition. Stored data can only be read and downloaded with special equip­
ment.
Electronic Stability
Control (ESC)
Description
ESC helps to improve road holding and vehicle
dynamics to help reduce the probability of
skidding and loss of veh icle control. It works
only when the engine is running. ESC detects
Intelligent technology 187
certain difficult driving situations, including
when the vehicle is beginning to spin (yaw)
out of control and helps you to get the veh icle
back under control by se lectively braking the
wheels, and/or reducing engine power and
providing steering ass istance to help hold the
vehicle on the driver's intended course. The in­
dicator light
Ip.] in the instrument cluster
blinks when ESC is taking action to help you
control the vehicle.
ESC has limitations .
It is important to remem­
ber that ESC cannot overcome the laws of
physics.
It will not always be able to help out
under all conditions you may come up against.
For example, ESC may not always be able to
help you master situations where there is a
sudden change in the coefficient of friction of
the road surface. When there is a section of
dry road that is suddenly covered with water,
slush or snow, ESC cannot perform the same
way it would on the dry surface . If the vehicle
hydroplanes (rides on a cushion of water in­
stead of the road surface), ESC will not be
able to help you steer the vehicle because con­
tact with the pavement has been interrupted
and the vehicle cannot be braked or steered .
During fast cornering, particularly on winding
roads, ESC cannot always deal as effectively
with difficult driving situations than at lower
speeds. When towing a trailer, ESC is not able
to help you regain control as it would if you
were not tow ing a trailer.
Always adjust your speed and driving style to road, traffi<; and weather conditions. ESC can­
not override the vehicle's physical limits, in­
crease the available traction, or keep a veh icle
on the road if road departure is a result of
driver inattention. Instead, ESC improves the
poss ibility of keeping the vehicle under con­
trol and on the road dur ing extreme maneu­
vers by using the driver's steering inputs to
help keep the vehicle going in the intended di­
rection. If you are traveling at a speed that
causes you to run off the road before ESC can
provide any assistance, you may not experi­
ence the benefits of ESC.
•
•

188 Intelligent technology
ESC includes and/or works together with the
anti-lock braking system (ABS), brake assist
system, anti-s lip regulat ion (ASR), e lectronic
d ifferential lock ( EDL), dynamic steering* and
e lectronic interaxle differentia l lock*. ESC is
switched on all the time. I n certa in s ituations
when you need less tract io n, you ca n sw itch
off ASR by pressi ng the button above
~ page 189, fig. 167 the se lector lever. Be
sure to sw itch ASR on ag ain when you no lon­
ger need less trac tion.
Anti -lock braking system (ABS)
ABS prevents t he wheels from locking up
when braking. The veh icle can still be st eered
even d uring ha rd b rak ing . Apply steady p res­
sure to the br ake ped al. Do no t pu mp the ped­
a l. A puls ing in t he bra ke peda l ind icates that
the system is he lping yo u to b rake the vehicle .
Brake assist system
The brake assist system can decrease b ra kin g
d ista nce. It increases braking powe r w hen the
d river p resses the brake pedal quickl y in eme r­
gency situa tions . You mus t press and ho ld the
b rake peda l until the situation is over. In vehi­
cles with adaptive cruise control*, the brake
assist system is more sensitive i f the d istance
detected to the vehicle ahead is t oo smal l.
Anti-slip regulation (ASR)
ASR reduces engine power w hen the drive
wheels begin to spin and adapts the fo rce to
the road condit ions. This makes it eas ier to
start, accelerate and drive up hills.
Electronic differential lock (EDL )
The E DL brakes wheels that are spinn ing and
transfers the drive powe r to the o ther d rive
wheel o r whee ls if the vehic le is equipped with
a ll whee l drive*. This funct ion is available up
to about 7S mph (120 km/h).
I n extreme cases , EDL automatica lly swit ches
off to help keep the brake on the braked whee l
from overheating. ED L wi ll switch on again au­
tomatically when conditions have returned to normal.
Dynamic steering*
On vehicles wi th dynam ic s teeri ng, ES C helps
stab ilize the steer ing in cer tain sit uations.
Electronic interaxle differential lock
function*
T he ele ctronic i nte raxle di fferentia l lock f unc ­
tion ac tiva tes when dr iving t hrough curves.
B ra king is targeted towar d the whee ls on the
inside of the curve as needed . This helps to
min imi ze front whee l skid, improves traction
and allows for more precise driving throug h
cu rves .
A WARNING
- ESC, ABS, ASR , EDL, dynamic steering*
and the elect ronic interaxle differential
loc k function* cannot ove rcome t he laws
of physics . This is espe cially im po rtant
on slippery o r we t road s.
If the sys tems
begin actin g to stabilize your veh icle, you
should immediately change yo ur speed
to match the road and t raffic conditions .
Do not let the increased safety provided
by these systems tempt you to take risks. Doing so will increase the risk of a loss of
veh icle cont ro l, collision and ser io us per­
sonal injur ies .
-Always ada pt your speed to road , traffic
and wea ther conditions. The risk of los­
ing contr ol of the vehicle i ncreases wh en
d riving too fast, espe cially through
curve s and on slippe ry or wet roads, and
when dr iv ing too close to vehicles up
ahead. ESC, ABS, the brake ass ist sys ­
tem, EDL, ASR, dynam ic steering * and
the elect ron ic interaxle differential lock
function * cannot prevent co llisions.
- Always accelerate with s pecial care on
even, smooth s urfaces such as those that
are wet or covered with ice and snow.
The drive wheels can spin even w ith
these assistance sys tems that cannot al­
ways he lp to red uce the risk of loss of ve ­
h icle co nt ro l.
-

192 Intelligent technology
be advisable to mount winter tires (or all-sea­
son ti res) for improved driveability and brak­
ing: these t ires must be mounted on
all four
w heels .
See also c> page 250, Winter tires.
Snow chains
Where snow cha ins are mandatory on certa in
roads, this normally a lso applies to vehicles
with A ll Wheel Driver=:>
page 251, Snow
chains.
Replacing wheels /t ire s
Vehicles w it h All Wheel Dr ive must always
have tires of the same size . Also avoid tires
with different tread depths. For details see
page
c> page 246, New tires and replacing
tires and wheels.
Off-Road driv ing?
Your Audi does not have enough ground clear ­
ance to be used as an off -road vehicle.
It is
therefore best to avoid rough tracks and un ­
even terrain as much as possible. Also refe r to
i=>page 195.
A WARNING
Always adjust your driving to road and traf­
fic condit ions. Do not let the extra safety
afforded by All Whee l Drive tempt you into
taking extra risks.
-Although the All Whee l Drive is very ef­
fective, a lways remember that b raking
capacity is limited by t ire traction. You
should the refore not dr ive at excessive
speeds on icy or slippery road su rf a ces.
- On wet road su rfaces, be careful not to
dr ive t oo fast becau se t he front wheels
co uld beg in to s lide on top of the wa ter
(aquaplaning) .
If this should occ ur, you
wi ll have no warning from a sudden in­
crease in engine speed as with a front­
wheel drive vehicle. A lways drive at
speeds wh ic h are suited to the road con­
ditions -risk of crash.
Energy management
Starting ability is optimized
Energy management controls the distribution
of electrical energy and thus optimizes the
availability of electrical energy for starting the engine.
If a vehicle with a conventiona l energy system
is not driven for a long per iod of t ime, t he bat­
te ry is discharged by idling current consume rs
(e.g. immobili ze r). In certa in circumstan ces it
ca n res ult in the re be ing insufficien t energy
available to start the eng ine.
Intelligent energy management in your vehi­
cl e ha ndles the dist rib ution o f electr ica l ene r­
gy. Start ing abili ty is m arkedly improved and
the life of the battery is extended .
Bas ica lly, energy management consists of
batt ery diagnosis , idling current manage­
ment
and dynamic energy management .
Battery diagnosis
Battery diagnosis continuously determines
the state of the batte ry. Sensors determine
batte ry voltage, battery cu rr e nt and battery
tempe ratu re. This de termines the cur ren t
state o f cha rge and t he power o f th e battery.
Idling current management
Idli ng current management reduces energy
consumpt ion while the vehicle is standing.
With the ig nition sw itched off, it controls the
energy supp ly to the variou s ele ctri ca l compo ­
nen ts. Da ta from ba ttery d iagnos is is co nsid­
ered.
Depend ing on the batte ry's state of cha rge,
i ndivid ual con sume rs a re g radually turned off
to prevent excessive discharge o f the battery
and th us main tain starting capabi lity.
Dynamic energy management
While the vehicle is being d riven, dynamic en­
ergy ma nagement distr ib utes the energy ge n­
era ted a ccord ing to t he needs of the individ u-
al components.
It r egula tes consumption, so
t h at more e lectrical energy is not being used ..,.

246 Tires and wheels
& WARNING
Sudden tire failure can lead to loss of con­
trol, a crash and serious personal injury!
- Never drive a vehicle when the tread on
any tire is worn down to the wear indica­
tors.
- Worn tires are a safety hazard, they do
not grip well on wet roads and increase
your risk of "hydroplaning" and loss of control.
- Always keep chemicals that can cause tire damage, such as grease, oil, gasoline
and brake fluid away from tires.
- Tires age even if they are not be ing used
and can fail suddenly, especially at high
speeds. Tires that are more than 6 years
old can only be used in an emergency
and then with special care and at lower
speeds.
- Never mount used tires on your vehicle if
you are not sure of their "previous histo­
ry." Old used tires may have been dam­
aged even though the damage cannot be
seen that can lead to sudden tire failure
and loss of vehicle control.
New tires and replacing tires and wheels
New tires and wheels have to be broken in .
Fig. 187 Tir e specificat ion codes on the s idewall of a
t ire
No. Description
(!) Passenger car tire (where applicable)
@ Nominal width of t ire in millimeters
@ Ratio of height to width (aspect ratio)
© Rad ial
® Rim diameter code
@ L oad index and speed rating
(J) U.S. DOT tire identification number
@ Audi Original tire
@ Sever snow conditions
@ T ire ply composition and materials
used
Maximum load rating
Treadwear, traction and temperature
grades
Maximum permissible inflation pres­
sure
T he tires and rims are essential parts of the
vehicle 's design . The tires and rims approved
by Audi are spec ially matched to the charac­
teristics of the vehicle and can make a major .,..

248 Tires and wheels
T up to 118 mph (190 km/h)
U up to 124 mph (200 km/h)
H up to 130 mph (210 km/h)
V up to 149 mph (240 km/h)
1l
Z over 149 mph (240 km/h)ll
W up to 168 mph (270 km/h)ll
Y up to 186 mph (298 km/h)l)
Your veh icle is normally factory equipped with
tires, which possess excellent driving charac­
teristics and give your Audi opt imum driving
comfort. An electronic speed limiter
c:> page 27 will normally prevent your vehicle
from going faster than the tire speed rating
c:> & .
U.S . DOT Tire Identification Number (TIN)
and tire manufacture date
This is the tire's "serial number". It begins
with the letters "DOT" and indicates that the
tire meets all federal standards. The next two
numbers or letters indicate the plant where it
was manufactured, and the last four numbers
r epresent the week and year of manufacture.
F or example, the numbers 2210 mean the tire
was produced in the 22nd week of 2010. The
other numbers are marketing codes that may
or may not be used by the tire manufacturer .
T his information is used to contact consumers
if a tire defect requires a recall.
Audi original tire
Tires with the identification "AO" or "RO" have
been specially matched with your Audi . We
recommend using only these tires because
they meet the highest standards regarding
safety and driving characteristics when used
correctly . Your authorized Audi dealer will
gladly provide you with more information .
Tire ply composition and materials used
The number of plies indicates the number of
layers of rubber-coated fabric in the tire. In
general, the greater the number of plies, the more weight a tire can support. Tire manufac -
ll F t· "t h .
o r ires w 1 a m ax im um spee d ca pabil ity ove r 149
mph (2 40 km/ h), ti re manufact urers sometimes use
the lett ers " ZR."
turers also must indicate the materials in the
tire, which include steel, nylon, polyester, and
others .
Maximum Load Rating
Th is number ind icates the max imum load in
kilograms and pounds that can be carried by
the tire .
Tire quality grading for treadwear,
traction , and temperature resistance
Tread wear, traction and tempera ture grades
c:> page 249.
Maximum Permissible Inflation Pressure
This number is the greatest amount of a ir
pressure that should ever be put in the tire
un der normal driv ing conditions .
_& WARNING
= -
- Using incorrect or unmatched tires and/
or wheels or improper tire and wheel
combinations can lead to loss of control
collision and serious personal injury.
'
- Always use tires, rims and whee l bolts
that meet the specifications of original factory-installed tires or other combina­
tions that have been specifically ap­
proved by the vehicle manufacturer.
- Tires age even if they are not being used
and can fail suddenly, especially at high
speeds. Tires that are more than 6 years
old can only be used in an emergency
and then w ith special care and at lower
speeds.
- Never mount used tires on your veh icle if
you are not sure of the ir "previous histo­
ry." Old used tires may have been dam­
aged even though the damage cannot be
seen that can lead to sudden tire fa ilure
and loss of vehicle control.
- All four whee ls must be fitted with radial
tires of the same type, size (rolling cir­ cumference) and the same tread pattern . ..,_

Driving with different tires reduces vehi­
cle handling and can lead to a loss of
control.
- If the spare tire is not the same as the
tires that are mounted on the vehicle -
for example with winter tires -only use
the spare tire for a short period of time
and drive with extra care. Refit the nor­
mal road wheel as soon as safely possi­
ble.
- Never drive faster than the maximum
speed for which the tires on your vehicle
are rated because tires that are driven
faster than their rated speed can fail
suddenly.
- Overloading tires cause heat build-up,
sudden tire failure, including a blowout
and sudden deflation and loss of control.
- Temperature grades apply to tires that
are properly inflated and not over or un­
deri nflated.
- For technical reasons it is not always
possible to use wheels from other vehi­
des -in some cases not even wheels
from the same vehicle model.
- If you install wheel trim discs on the ve­
hicle wheels, make sure that the air flow
to the brakes is not blocked. Reduced air­
flow to the brakes can them to overheat, increasing stopping distances and caus­
ing a collision.
- Run flat tires may only be used on vehi­
cles that were equipped with them at the
factory. The vehicle must have a chassis designed for run flat tires . Incorrect use
of run flat tires can lead to vehicle dam­
age or accidents. Check with an author­
ized Audi dealer or tire specialist to see if
your vehicle can be equipped with run flat tires. If run flat tires are used, they
must be installed on all four wheels. Mix­
ing tire types is not permitted.
- For technical reasons, it is not generally
possible to use the wheel rims from oth­
er vehicles. This can hold true for wheels
of the same vehicle type.
Tires and wheels 249
- If the spare tire is different from the
tires that you have mounted on your ve­
hicle (for example winter tires or wide
profile tires), then use the spare tire for a
short period of time only and drive with
extra care. Replace the flat tire with the
tire matching the others on your vehicle
as soon as possible .
- Never drive without the valve stem cap .
The valves could get damaged.
@) For the sake of the environment
Dispose of old tires in accordance with the
local requirements.
' Uniform tire quality grading
-Tread wear
- Traction AA A B C
- Temperature ABC
Quality grades can be found where applicable
on the tire side wall between tread shoulder
and maximum section width
c:> page 246,
fig. 187.
For example: Tread wear 200, Traction AA,
Temperature A.
All passenger car tires must conform to Feder­
al Safety Requirements in addition to these
grades.
Tread wear
The tread wear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
government test course.
For example, a tire graded 1S0 would wear
one and one half (11/2) times as well on the
government course as a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use, how­
ever, and may depart significantly from the
norm due to variations in driving habits, serv­
ice practices and differences in road character-
istics and climate. .,.. •
•

250 Tire s and wheel s
Traction
The traction grades, from highest to lowest,
are AA, A, Band
C. T hose grades represent the
tire's ability to stop on wet pavement as measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance
c:> .&. .
Te mp eratu re
The temperature grades are A (the highest),
B, and
C, representing the t ire's resistance to
the generat ion of heat and its ability to dissi­
pate heat when tested under con trolled cond i­
tions on a specified i ndoor laboratory test
wheel.
Sustained high temperature can cause the
material of the tire to degenerate and reduce
tire life, and excessive temperature can lead
to sudden tire failure
c:> ,& .
The grade C corresponds to a level of perform­
ance which all passenger car tires must meet under the Federa l Motor Veh icle Safety Stand­
ard No .
109 . Grades Band A represent h igher
l eve ls of pe rformance on the laboratory test
wheel than the m inimum required by law.
.&_ WARNING
T he traction grade assigned to this t ire is
based on stra ight-ahead braking traction
tests, and does not include acceleration,
cornering, hydrop laning o r peak traction
character istics.
A WARNING
The temperature grade for this t ire is es ­
tablished for a t ire that is properly inflated
and not ove rloaded. Excessive speed, un­
derinflation, or excessive loading, either
separately or in combination, can cause
heat buildup and possible ti re fa ilu re.
-
Winter tires
Winter tires can improve vehicle handling on
snow and ice . At temperatures below 45 °F
(7 °C) we recommend changing to winter
tires.
In some heavy snow areas, local governments
may require true w inter o r "snow" t ires , those
with very deeply cut tread . Th ese tires should
o n ly be used in pairs and be installed on a ll
f o ur wheels . Make sure you p urch ase snow
t ir es that are the same size and cons truction
type as the othe r tires on yo ur vehicle.
If your vehicle i s equ ipped w ith all-whee l
drive*, t his w ill improve tr action d uring win ter
driv ing, even with the standard tires . Howev ­
er, we strongly recommend that you always
equip all four wheels on your vehicle w ith cor­
rect ly fitted winter tires or all-season t ires,
when winter road condit ions are expected.
This also improves the veh icle 's brak ing per­
formance and reduces stopping d istances .
Summer tires provide less grip on ice and
snow.
Winter tires (snow tires) must always be fitted on all fo ur whee ls .
As k your au thori zed A udi dealer or qualified
workshop for permit ted
winter tire size s. Use
only radial winter tires .
Winter tires lose their effec tivenes s whe n the
tread is wo rn down to a depth o f
0.1 57 inch
(4 mm) .
Only d rive w ith w inter t ires under w inte r co n­
di tions. S umme r tir es handle be tte r whe n
the re is no snow o r ice on the roa ds and the
temperatu re is above 45 °F (7 °C) .
If you have a flat ti re, see notes on spare
whee l
c:> page 246 .
Please always remember that winter tires may
have a lowe r speed rating than the tires o rigi­
nally i nstalled on your vehi cle at the time it
was manuf actu red. P lease see
c:> page 247,
Speed ra ting (Letter code)
fo r a lis ting o f the
speed rating lette r codes and the max imum
speed at which the tires can be driven . ..,.