2012 AUDI S8 engine

136 Safety belts
occupant will slam violently into the steering
wheel, instrument panel, windshield, or what­
ever else is in the way
c::> fig. 138. This impact
with the vehicle interior has all the energy
t hey had just before the crash.
Never rely on a irbags alone for protection.
Even when they deploy, airbags provide only
additional protection. Airbags are not sup­
posed to deploy in all kinds of accidents. Al­
though your Audi is equipped with airbags, all
vehicle occupants, including the driver , must
wear safety belts correctly in order to mini­
mize the risk of severe injury or death in a
crash.
Remember too, that airbags will deploy only
once and that your safety belts are always
there to offer protection in those accidents in
which airbags are not supposed to deploy or
when they have already deployed . Unbelted
occupants can also be thrown out of the vehi­
cle where even more severe or fatal injuries
can occur.
It is also important for the rear passengers to
wear safety belts correctly. Unbelted passen­
gers in the rear seats endanger not only them­
selves but also the driver and othe r passen­
gers ~
fig. 139. In a frontal collision they will
be thrown forward violently, where they can
hit and injure the driver and/or front seat pas­
senger .
Safety belts protect
People think it's possible to use the hands to
brace the body in a minor collision . It's simply
not true !
Fig. 140 Driver is co rr ect ly re strain ed in a sudd en brak­
ing maneuve r
Safety belts used properly can make a big dif­
ference. Safety belts help to keep passengers
in their seats, gradually reduce energy levels
applied to the body in an accident, and help
prevent the uncontrolled movement tha t can
cause serious injuries . In addition, safety belts
reduce the danger of being thrown out of the
vehicle .
Safety belts attach passengers to the car and
give them the benefit of being slowed down
more gently or "softly" through the "give" in
the safety belts, crush zones and other safety
features engineered into today's vehicles. By
"absorbing " the kinetic energy over a longer
period of ti me, the safety belts make the
forces on the body more "tolerable" and less
likely to cause injury.
Although these examples are based on a fron­
tal collision, safety belts can also substantial­
ly reduce the r isk of injury in other kinds of
crashes. So, whether you're on a long trip or
just going to the corner store, always buckle up and make sure others do, too. Accident sta­
tistics show that vehicle occupants properly
wearing safety belts have a lower risk of being
injured and a much better chance of surviving
an accident. Properly using safety belts also
greatly increases the ability of the supplemen­
tal airbags to do their job in a collision . For
this reason, wearing a safety belt is legally re­
quired in most countries including much of
the United States and Canada.
Although your Audi is equipped with airbags,
you still have to wear the safety belts provid­
ed. Front airbags , for example, are activated
only in some frontal collisions. The front air­
bags are not activated in all frontal collisions,
in side and rear collisions, in roll overs or in
cases where there is no t enough decelera tion
through impact to the front of the vehicle .
The same goes for the other airbag systems in
your Audi . So, always wear your safety belt
and make sure everybody in your vehicle is
properly restrained!

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.
-

@ Tips
-ABS and ASR on ly work correctly when
all four wheels are equ ipped with identi­
cal t ires. Different tire s iz es can lead to a
reduct ion in eng ine power.
- You may hear noises when the systems
described are working.
- If the indicator light
D] or m (USA
models) ;£1 (Canada models) appears,
there may be a malfunction¢
page 19,
c> page
18 .
Switching on and off
ESC
turn s on au tomatically when you s tart
the engine .
Fig. 167 Cen te r con sol e wit h ES C OF F but ton
Switching ASR off (sport mode )
In certain sit uat ions, you can switch ASR and
ESC in to sport mode by pressing the bu tton
[ru
c> fig. 167 . The indicator light I comes o n
and the message
Cauti on! R edu ced t ra cti on
appears. ASR deactivates completely and the
assistance provided by the ESC system is lim it­
ed . Switch to sport mode only when your driv ­
ing skills, traffic and weathe r conditions per­
mi t.
I n some s ituations, it may be useful to switc h
ASR off to let the wheels slip. Example:
- Rocking the vehicle back and forth when it is
stuck
- Driv ing in deep snow or on loose ground
- Driving with snow cha ins
Switching ASR on
Press the button [fil again. The message Sta­
bility program on
appears.
Intelligen t technolog y 189
A WARNING
-Drive whee ls can sp in and you can lose
control of the vehicle more eas ily when
ASR and ESC are in sport mode, especial­
ly whe n the road is slippe ry .
- Sw itch to sport mode only when your
driving skills, traff ic and weather condi­
tions permit.
(D Tips
You cannot sw itch sport mode on whe n
adaptive cruise control* is working .
Braking
General information
What affects braking efficiency?
Operating cond itions and driving h abits
The brakes o n today's automobiles are still
subject to wear, depend ing largely on operat­
i ng condit ions and driving habits ¢&, . On ve­
hicles that a re either dr iven most ly in stop­
and-go c ity t raff ic or are dr iven hard, the
brake pad s should be checked by yo ur author ­
i zed Audi dealer more often than specified in
the
Warranty & Maintenance booklet. Failure
to have your brake pads inspected can result in reduced brake performance.
On steep slopes, you sho uld use the braking
effect of the eng ine . T his way, you prevent un­
necessary wear on the brake system . If you
must use your brakes, do not hold the br akes
down cont inuous ly . Pump the brakes a t in ter­
vals .
Moisture o r ro ad sa lt
Under certa in conditions, for example, when
driv ing through water or very heavy ra in, or
even after washing your veh icle, the braking
effec t can be reduced due to moisture (or in
freez ing cond itions ice) on the brake pads . A
few carefu l brake applications should dry off
the b ra ke pads or remove a ny ice coatings.
When you are driving a t higher speeds with
the windsh ie ld w ipers on , the brake pads will
IJJJ,

190 Intelligent technology
briefly touch the brake discs in regular inter ­
va ls so as to improve reaction time when brak­
ing on wet surfaces. You the driver wi ll not no­
tice anything.
The effectiveness of the brakes can be reduced
when the vehicle is driven on a salt-covered road and the brakes are not used. Here too,
you sho uld clean off accumu lated salt coat ing
from brake d iscs and pads with a few careful
applicat ions of the brake¢,& .
Cor ro sion
There may be a tendency fo r dirt to bui ld up
on the brake pads and corrosion to form on
the discs if the car is not dr iven regularly or
only for short trips with little use of the
brakes .
If the brakes are not used frequently, or if cor­ rosion has formed on the discs, it is advisab le
to clean off the pads and discs by brak ing
firm ly a few times from a moderately high
speed <=>,& .
Fault s in the brake sy stem
If you should notice a sudden increase in
brake peda l travel, then one of the two brake
circu its may have failed¢,& .
Low brake flu id le vel
M alfunctions can occur in the brake system if
the brake fl uid level is too low. The brake fluid
leve l is monitored electronically .
Brake lining wear status
Brake lin ing wea r may be chec ked by v is u al in­
spection of the condition of the brake pads
through the openings in the whee l. If neces ­
sary, the whee l may be removed for this in­
spection ¢ page 2 59, Changing a wheel.
A WARNING
-You should perform brak ing maneuvers
for the purpose of clean ing the brake
system on ly if road con ditio ns pe rmit.
Oth er road users must not be put at r isk -
yo u may cause an ac ciden t! -
Before descend ing a steep grade, red uce
speed and sh ift transmission into a lower
gear or lower dr iving range. Do not ride
the brakes or hold the pedal down too
long o r too often . This could cause the
brakes to get hot and diminish braking
efficie ncy.
- Do not "ride the brakes" by rest ing you r
foot on th e pedal whe n you do not intend
to b rake. This may c ause the brake s to
overhea t, prem ature wear and incre ased
stopping distance.
- Unde r cert ain cl im atic and ope rat ing
conditions s uch as passing thro ugh wa ­
ter, driving in heavy rain o r after washing
the vehicle, the effectiveness of the brakes can be reduced. In winte r, ice can
accumu late on the brake pads, lin ings,
d iscs and drums. Carefully app ly brakes
for a test. Brakes will dry and ice coat­ i n gs w ill be cleaned off after a few care­
fu l brake applicat ions.
- Driving for an extended period of t ime on
salt-covered roads without using your
b rakes can a lso affect bra kin g efficiency .
Clea n off accum ulate d sal t coa ting from
b rake discs and pads wi th a few c areful
b rake applications .
- If you d am age t he fron t spoiler, or i f yo u
install a diffe rent spoiler, be s ure the a ir
f low to the front brakes is not obstruc t­
e d. Otherwise the brake system could
overheat reducing the effectiveness o f
the entire brake system.
- Fa ilure of one brake circuit will impa ir
the braking capab ility result ing in an in­
creased stopping distance. Avoid driving
the vehicle and have it towed to the near­
est A udi dealer or qualified workshop .
Brake booster
The brake booster adds extra braking power.
T he brake booster wo rks with vacuum pres­
s ur e which is created only when the engine is
runn ing
c> ,& . ..,.

& WARNING
-Never let the vehicle roll to a stop with
the engine shut
off.
- If the brake booster is not working, for
example when towing your vehicle, or
because the brake booster has somehow
been damaged, the brake pedal must be
pressed considerably harder to make up
for the lack of booster assistance.
Servotronic ® -
advanced power
steering system
-
The power steering systems use the power of
the running engine to allow precise steering
with little effort.
The advanced Servotronic ® power steering
system senses the road speed and e lectroni­
cally adjusts power ass istance to provide com­
fortable and safe steering response exactly matched to the veh icle speed.
Power steering wi ll not work if the engine is
off. As a resu lt, the steering whee l wi ll be hard
to turn.
The power steering fluid level is checked dur­ ing the scheduled maintenance services.
(D Note
I f there is an electronic malfunct ion, ser­
votronic
will sti ll function like a conven­
tional power steering system, providing a
constant steering support force that is no
longer proportionate to the vehicle speed.
This is most noticeable when turning the steer ing whee l at low speeds (for examp le
when parking), -more effo rt will be re­
qui red than usual.
- Be awa re of the different than usual
steering response and adjust your stee r­
i ng fo rce accord ingly.
- Have the p roblem checked and set right
by an Aud i dealer as soon as possib le .
Int ellig ent technolog y 191
(D Tips
-When the engine is running, never ho ld
the steering wheel turned all the way to
the right or to the left for longer than 15
seconds. The power steering pump will
overheat the hydrau lic fluid if you keep
holding the stee ring wheel turned all the
way. This is likely to damage the power
steering system.
- If the powe r stee ring system should fa il
entire ly, o r if the e ngine is not run ning
(for example, wh ile be ing towed), you
w ill still be able to stee r the veh icle.
However,
considerably more effor t will
be required to do so .
- If the power stee ring system sho uld
have a lea k, or is not functioning proper ­
ly, contact your authorized A udi dealer
immediately.
- The power steering system req uires a
specially formu lated hydra ulic fluid. The
power steering fluid reservoir is located
in the engine compartment
Q page 221.
The correct fluid level in the reservoir is
important for proper functioning of the
powe r stee ring.
Driving with your
quattro ®
With All Wheel Drive, all four wheels ore driv­
en.
General information
Wi th A ll Wheel Drive, power is dis tributed to
all four w heels. This happens automatically
depend ing on your driving style and the road
conditions at the time . See a lso
Q page 187.
With the sport different ia l*, power distribu­
tion to the rear wheels is variable and can be
adjusted with Audi drive select*
Qpage 103.
Always read and follow safety precautions
Q&_ ,
Winter tires
When dr iving in the winter, yo ur vehicle with
A ll Wheel Drive has an advantage, even w ith
regular tires. In winter road conditions it may ..,. •
•

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 ..,.

than is being generated and ensures an opti­mal state of charge for the battery.
@ Tips
- But even energy management cannot
negate the limits o f physics. Consider
that the power and life of a battery are
li mited.
- If starting ab ility is threatened, the indi­
cator light
(•i appears ~ page 16, 0
Battery.
What you should know
The highest priority is given to maintaining
starting capability.
The battery is severely taxed in short-dis tance
d riving, in city traffic and during the co ld time
of year . Abundant e lectrica l energy is re­
q ui red, but only a litt le is generated. It is also
cr itical if the engine is not runn ing and electri­
cal components are turned on. In th is in­
stance energy is being consumed but none is
be ing generated .
It is in precisely these situations that you w ill
notice energy management actively regulat­
i ng the distribution of energy.
Vehicle sta nds for an ext ended p eriod
If you do not drive you r vehicle over a period
of several days or weeks, electrical compo­ nents are grad ually cut back or switched
off .
This reduces energy consumption and main­
tains sta rting capab ility over a longer per iod.
Some of the conven ience f unctions may not
ope rate, such as the inter ior lig hts or the
power sea t adjustment. The conven ien ce
f u nctions w ill be ava ilable again when you
switch on the ignit ion and start the engine .
With the engine turned off
If you listen to the radio, for example, with
the engine turned
off or use other MMI func­
tions, the battery is being discharged .
If starting capability is jeopa rdized due to en­
ergy consumpt ion, the fo ll ow ing warning ap­
pears in the MMI display :
Intellig ent technolog y 193
Plea se start the engine soon or the sy stem
will be turned off .
The wa rni ng ind ic ates that the system wi ll be
tu rned
off automatically a fter 3 minu tes. If
you w ish to continue using the funct ions, yo u
have to start the engine.
With the engine running
Althoug h elec trical energy is generated when
t h e ve hicl e is being driven, t he battery can be­
come d ischarged. This happe ns mostly when
little energy is being generated and a great
deal consumed and the battery's state of
charge is not opt imal.
T o b ring the energy ba lance back in to equili ­
brium, consumers which require especially
l a rge amounts of energy a re temporari ly cut
back or sw itched
off. Heat ing systems in par­
ticular require a great deal of energy. If you notice, for example, that the heated seats* or
the heated rear window are not heating, they
have been temporarily cut back or switched
off . These systems w ill be available again as
soon as the ene rgy balance has been restored.
You w ill also notice that engine id le speed has
been increased slightly . Thi s is normal and not
a cause for concern. By inc reasing engi ne id le
speed the additional e nergy requi red is gene r­
ated and the b attery is charged.
•
•