2009 AUDI S8 width

• .___A_ u_ d_ i_s_ i_ d _e_ a_ s_ s_i s_ t __________________________________________________ _
Applies to vehicles: with side ass ist
Sensor detection area
Fig. 176 Sc hem ati c
illu str ati on : Sens or
d etec tio n area
The detection ~ fig. 176 of the radar sensor detection area is made
up of:
• the approach area !light green area)
0, about 230 feet (70 ml
behind the veh icle, and
• the "blind spot" (dark green areal@.
The radar sensors cover the adjacent left and right lanes. Other
lanes are
not covered by the radar sensors .
[ i ] Tip s
Side assist does not measure actual lane width . The system
assumes a fixed lane width. Detection in the left and right lanes is based on this assumed lane width. When driving on narrow roads or
when driving to the left or right of the center of a travel lane, it is
possible that vehicles will be detected that are
not in the lane next
to the lane you are using~
page 163. •
Applies to vehicl es: with side assist
Operation
Side ass ist compares the distance and difference in speed of
detected vehicles with the speed of your vehicle. Whenever the
difference in speed and distance is registered as notab le if you were
to change lanes, a signal light appears on the respective mirror.
The signal can light up if you are passed by a vehicle or if you are
passing another vehicle.
If you pass another vehicle slowly (difference in speed less than 9 mph, or
15 km/h), the signal light will come on as soon as the other
vehicle is in your blind spot and is detected by side assist. When the
difference in speed is greater, the signa l light will not come on .•
Applies to vehic les : w ith side assist
Informational and alert stage signals
Side assist has two signal stages:
• the informational stage signal, and
• the alert stage signal.
Side assist helps you by using the appropriate signa l stage,
depend ing on whether or not you have act ivated the turn signal,
and thus have indicated that you are or are not changing lanes.
In fo rm ati onal stag e signal
As long as you have not activated the turn signa l, side assist informs
you of detected vehicles that are registered as being in a notable location if you were to change lanes. Whenever the detected
vehic le's difference in speed and distance is registered by side
assist as notable, the signa l light on the respective mirror produces
muted il luminatio n.
The brightness of the informationa l stage signal is designed not to
be as intense, so that it does not interfere with your view of the road
when you are driving and have no intention of changing lanes. .,,,

___________________________________________________ A_u_ d_i_ s_ id_e_ a_ s_s _i_s _t _ __.ffllll
Ap plies to vehicle s: with side assist
General information
Side assist has lim its and cannot detect vehic les under all road and
weather conditions. P lease remember system limitations and
never
rely on the system, especially when:
• driving through curves=>
page 763,
• lanes are of different widths=> page 163. •
Applie s to vehicles: with side ass ist
When dr iving through curves
Side assist cannot detect vehicles in curves with a turning radius of
less than 328 feet (100 m).
When driving through a curve , it is possible that side assist may
register a vehicle two lanes
over, and the signal on the outside
m irror will ligh t up .•
A pplies to vehicle s: with side ass is t
Lane width
Con tro ls and eq uip­
ment
-
Fi g. 183 Lanes o f a
n orm al w idth are in
d etec tion a rea
Fig . 18 4 Narrow l anes:
Si de ass is t m ay d etec t
v ehicle s tw o la ne s
a w ay
Side assist's detection area is designed to cover lanes of standard
width to the le ft and right o f your trave l lane, depending on whethe r
you drive in the center of your lane or c loser to the edge.
If you drive in narrow lanes, side assist's detection area may also
inc lude other lanes -especially if you tend to dr ive on the edge o f
your lane=> fig . 184. Under these conditions, vehicles can also be
de tected tha t are two lanes away, and s ide assist then could switch
between the informational and warning stage signa ls.
When d riving in
very wide lanes, vehicles in the adjacent lane may
not be detected because they are not inside the detection area. •
Notes
Applies to veh ic les : with s ide ass ist
Messages in instrument cluster display
If side assist turns off automatically, the indicator light on the
button will go out and you will see a message in the instr ument
cluster display:
Audi side a ssist not available : sensors po ssibly blocked
The side assist sensors are built into the rear bumper on the left and
right ( not visible on the outside) =>
page 156, fig. 173 . To ensure that
you do not adversely affect the way side assist functions, foreign .,_
Vehicle care I I irechnical data

• .___A_ u_ d_ i_s_ i_ d _e_ a_ s_ s_is _ t __________________________________________________ _
objects (such as stic kers o r bicyc le rac ks) shou ld no t be attach ed to
th e ar ea on the rea r bump er where t he sen so rs ar e loca ted. I f side
assist functions are adve rsely aff ect ed, you will see this m essage in
th e ins trum ent clu ster dis pla y. Remove an ything that may be
blocking the sensors.
If no veh ic le is detected for a longer period of time while d riving,
s id e ass ist w ill a lso sw itc h off aut omat ica lly.
Audi side assist currently not available
If th ere is a tem porary prob le m (such as the veh ic le 's battery char ge
being low), side ass ist cannot be activated tem porar ily .
Audi side assist: system fault
Have the sys te m chec ked by an a uthorize d A udi dea ler o r qua lified
wor ks h op. •
App lies to veh icles : wi th side ass is t
Safety tips
The side ass is t de tect io n m ay be limi ted whe n driving a round
narrow s treet corners, on hilly streets, and under poor w eat he r
condit ions.
It is possibl e that the r ad ar sen so rs may also d etect oth er obje cts,
such as high or staggered guardrails.
Sid e assis t does no t measure ac tual lane w idth. The sys te m
assu mes a fixed lane widt h. D etect ion in the left and right lanes is
based on thi s assumed lane width . When driving on na rrow roads or
when driv ing to th e left or right of the c enter o f a trav el lane, it is
possible that veh ic les wi ll be detected that are
not in the lane next
to the l ane y ou are us ing .
& WARNING
• Improper reliance on the side assist system can cause colli­
sions and serious personal injury:
& WARNING (continued)
- Never rely only on side assist when changing lanes .
- Always check rear view mirrors to make sure that it is safe to
change lanes .
• Side assist cannot detect all vehicles under all conditions ­
danger of accident !
• Side assist cannot detect vehicles
in time to alert you when
they approach from behind at very high speed , or fall drop back
very quickly.
• The radar sensor's
vision can be reduced or entirely blocked by
rain , snow , and heavy spray. This can result in side assist not
adequately detecting vehicles or, in some cases, not detecting
them at all . Always keep an eye on the direction you are traveling
and the relevant area around the vehicle .
• Please note that side assist indicates there are approaching
vehicles , or vehicles in your blind spot , only after your vehicle has
reached a driving speed of at least 19 mph (30 km /h) .
• Side assist signal does not work around tight corners (turning
radius less than 328 feet , or 100
ml.
• Side assist is no replacement for the driver's full attention. The
driver alone is responsible for lane changes and similar driving
maneuvers . Always keep an eye on the direction you are traveling
and the relevant area around the vehicle .
0 Note
To ensure that s ide assist is not adversely affected , you s hou ld not
block the area on the rea r bumper where the radar sensors a re
l ocated with fo rei gn ob jec ts (such as w ith sti ckers or b icycl e rac ks!. .,,_

-~_T_ ir_e_ s_ a_ n_d _ w_ h_ e_e _l_s _________________________________________________ _
Groove
means the space between two adjacent tread ribs.
Load rating (code)
means the maximum load that a tire is rated to carry for a given
inflation pressure . You may not find this information on all tires
because it is not required by law.
Maximum load rating
means the load rating for a tire at the maximum permissible infla­
tion pressure for that tire.
Maximum loaded vehicle weight
means the sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight, and
(d) Production options weight
Maximum (permissible) inflation pressure
means the maximum cold inflation pressure to which a tire may be
in flated. Also called "maximum inflation pressure ."
Normal occupant weight
means 150 lbs. (68 kilograms) times the number of occupants
seated in the vehicle up to the total seating capacity of your vehicle.
Occupant distribution
means distribution of occupants in a vehicle .
Outer diameter
means the overall diameter of an inflated new tire.
Overall width
means the linear distance between the exteriors of the sidewalls of
an inflated tire, including elevations due to labeling, decorations, or
protective bands or ribs .
Ply
means a layer of rubber -coated parallel cords.
Production options weight
means the combined weight of those installed regular production
options weighing over 5 lbs. (2.3 kg) in excess of those standard
items which they replace, not previously considered in curb weight
or accessory weight, including heavy duty brakes, ride levelers, roof rack, heavy duty battery, and special trim.
Radial ply tire
means a pneumatic tire in which the ply cords that extend to the
beads are laid at substantially 90 degrees to the centerline of the
tread.
Recommended inflation pressure
see =:> page 327, "Cold tire inflation pressure".
Reinforced tire
means a tire design to operate at higher loads and at higher infla­
tion pressures than the corresponding standard tire. Reinforced
tires may be identified as "XL", "xi", "EXTRA LOAD", or "RF" on the
sidewall.
Rim
means a metal support for a tire or a tire and tube assembly upon
which the tire beads are seated .
Rim diameter
means nominal diameter of the bead seat. If you change your wheel
size, you will have to purchase new tires to match the new rim diam ­
eter.
Rim size designation
means rim diameter and width.
Rim width
means nominal distance between rim flanges .

___ T_ i_ r_e _s_ a_ n_ d_ w_ h_ e_ e _ ls _________________________________________________ _
Incorrect wheel alignment
Incorrect wheel alignment can cause excess ive tire wea r, im pairing
the safety of the vehic le. If tires show excessive wear, have the
whee l alignment c hecked by an au th o rize d Audi deale r or qualifie d
wo rkshop.
All Wheel Drive
Vehicles with quattro® must always have tires of the same size, c ons truc tion and tread type. F or details see
~ p age 275 .
& WARNING
Sudden tire failure can lead to los s of control, a crash and serious
personal injury !
• Never drive a vehicle when the tread on any tire is worn down
to the wear indicators .
• 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 dam age , such as
grease, oil , gasoline and brake fluid aw ay from tires .
• 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 with special care and at
lower speeds .
• Never mount used tires on your vehicle if you are not sure of
their "previous history." Old used tires may have been damaged
even though the damage cannot be seen that can lead to sudden
tire failure and los s of veh icle control. •
New tires and replacing tires and wheels
New t ires and wheels h ave t o be broke n in.
Fig . 278 T ir e specif ication cod es on the sidewall of a tir e
No.
©
0
©
©
©
©
Description
Passenger car tire (where applicable)
Nominal width of tire in millimeters
Ratio of height to width (aspect ratio)
Radial
Rim diameter code
L o ad in dex and s peed ra ting

________________________________________________ T_ i _r_e _s_ a_n_ d_ w_ h_ e_e _ l_s __ lR
•
0
-
©
®
U.S. DOT ti re identification number
Sever snow conditions
Tire ply composition and materials used
Maximum load rating
Treadwear , traction and temperature grades
@ Maximum permissible inflation pressure
The tires and rims are essential parts of the vehicle 's design. The
tires and rims approved by Audi are specially matched to the char­
acteristics of the vehicle and can make a major contribution to good
road hold ing and safe handling when in good cond ition and prop­
erly inflated =>& .
We recommend that a ll work on tires and wheels be performed by
an authorized Audi dealer. They are familiar with recommended
procedures and have the necessary special tools and spare parts as
well as the proper facilities for d isposing of the old tires.
Authorized Audi dea lers have the necessary info rmation about tech ­
nical requirements for insta lling or changing tires and rims.
R epl ac ing tires and wheels
Tires shou ld be replaced at least in pairs and not individually (for
examp le both front tires or both rear tires together).
Be sure to read and heed the information to the tire pressure moni ­
toring system*=>
page 340.
Always buy replacement radial tires that have the same specifica ­
tions as the tires approved for your vehicle by Audi. Rep lacement
tires must always have the same load rating specification as the
origina l equipment or approved optional t ires listed in the table
=>
page 330.
Audi -appr oved spec ification tires are spec ially matched to your
vehicle and its load limits, and can contribute to the important road- holding, driving characteristics, and safety of the vehicle
. The table
(=>
page 330) l ists specifications of the tires approved for the Audi
models covered by your Owner's Literature.
The tire pressure labe l located either on driver's side 8 -pi llar or
inside the fuel fi ller flap(=>
page 330, fig. 275) lists the specifica ­
tions of the original equipment tires installed on your vehicle at the
ti me it was manufactured.
Federa l law requires tire manufacturers to place standardized infor ­
mation on the sidewa ll of all tires =>
page 338, fig . 278. This informa ­
t ion identifies and describes the fundamental characteristics, the
qua lity grade of the ti re and also provides a tire identification
number for safety standard certificat ion and in case of a recal l.
Tire specificat ions
Knowledge of tire specifications makes it easier to choose the
co rrect t ires . Radial tires have the tire specifications marked on the
sidewall, for example:
255 /45 R 18 99 H
This contains the following informat ion:
P Indicates the ti re is for passenger cars (where applicab le)
255 No minal tire width i n mm of the tire fro m sidewall edge to side -
wa ll edge. In general, the larger the number, the wider the tire
45 Height/width ratio in percent (aspect ratio)
R Tire construction: Radial
18 Rim diameter code (in inches)
99 Load rating code
H Speed rating lette r code
XL (or "xi", "EXTRA LOAD" or "RF") indicates that the tire is a "Rein­
forced" or an "Extra Load" ti re
M +S (o r "M/S") Indicates that the tire has some mud and snow capa ­
bility
The tires could a lso have the information of direct ion of rotation
=>
page 326.
Vehicle care I t •

-~_T_ ir_e_ s_ a_ n_d _ w_ h_ e_e _l_s _________________________________________________ _
• If the spare tire is different from the tires that you have mounted
o n your vehi cle (for e xample winter tires or wide profile tires), then
use the spare tire for a short period of time on ly and drive with extra
care . Replace the f lat tire with the tire matching the others on your
vehicle as soon as possible.
• If you should put different wheels and tires on your vehicle (e.g.
winter wheels and tires), you must be certain that the wheels and
tires are compatible with the tire pressure monitoring system* .
Otherwise the system will register a ma lfunction and a fault
message will be displayed . For more information, contact your Audi
dea ler.
0 Note
• When installing new tires, be careful not to damage the valves or
tire pressure monitoring system* sensors.
• Never drive without the va lve stem cap. The valves could get
damaged.
• If the sensors must be replaced, then the valve must also be
replaced at the same time.
c£> For the sake of the environment
Dispose of old tires in accordance with the loca l requirements. •
Uniform tire quality grading
• Tread wear
• Traction AA A B C
• Temperature A B C
Qua lity grades can be found where applicable on the tire side wal l
between tread shoulder and maximum section width
=> page 338,
fig. 278.
For e xample: Tread wear 200 , Traction AA, Temperature A.
All passenger car tires must conform to Federal Safety Require­
ments in addit ion to these grades.
Tread w ea r
The tread wear grade is a comparative rating based on the wear rate
of the tire when tested under contro lled conditions on a specified
government test course.
For example, a tire graded 150 wou ld wear one and one half (1 1/2)
times as well on the government course as a tire graded 100.
The relative performance of tires depends upo n the actua l condi­
tions of their use, however, and may depart significantly from the
n orm due to variations in d riving habi ts, service practices and differ­
ences in road characteristics and climate.
Tra ction
The traction grades, from highest to lowest, are AA, A, Band C.
Those grades represent the tire's ability to stop on wet pavement as
measured under contro lled conditions on specified government
t est surfaces of asphalt and concrete . A tire marked C may have
poor traction performance => & .
Temperature
The temperature grades are A (the highest), 8, and C, representing
the tire's resistance to the generation o f heat and its abi lity to dissi ­
pate heat when tested under control led conditions on a specified
indoor laboratory test wheel.
Sustained high temperature can cause the mater ial of the tire to
degenerate and reduce tire life, and excessive temperature can lead
to sudden tire failure=>&.
T he grade C corresponds to a leve l of performance which a ll
passenger car tires must meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades Band A represent higher levels of
p er formance on the la b ora tory test whee l than t he mi nimum
required by law.
~

Tires and wheels 1111111 ________________________________ ::..:..:....::.=.....::.:..:..:..::..:___:__ _ ___:,___
•
Wheel bolts
Wheel bolts mus t alwa ys be tighte ned to t he correct
to rq ue .
The design of wheel bo lts is matched to the factory installed rims. If
di fferent r ims are fitted , th e cor rect whe el bo lts wi th the rig ht l ength
and c orrec tly shaped bolt heads must be used . This ens ures that
w he els a re fitted se cur ely and th at the bra ke syste m functi ons
correctl y.
In cer ta in c ircums tances, yo u ma y not use w hee l bolts fr om a
differ ent vehicle - even if it is the same model~
page 384 .
& WARNING
Improperly tightened or maintained wheel bolts can become loose
causing loss of control, a collision and serious personal injury.
• Always keep the wheel bolts and the threads in the wheel hubs
clean so the wheel bolts can turn easily and be properly tightened .
• Never grease or oil the wheel bolts and the threads in the wheel
hubs. They can become loose while driving if greased or oiled,
even if tightened to the specified torque .
• Only use wheel bolts that belong to the rim being installed .
• Never use different wheels bolts on your vehicle.
• Always maintain the correct tightening torque for the wheel
bolts to reduce the risk of a wheel loss .
If the tightening torque of
the wheel bolts is too low, they can loosen and come out when the
vehicle is moving . If the tightening torque is too high, the wheel
bolts and threads can be damaged and the wheel can become
loose .
0 Note
The s pecified torque for the wheel bolts is 90 ft lb ( 120 N m) with a
to lerance o f± 7,4 ft lb(± 1 0 Nm). Torque whee l bolt s diago nally.
After chang ing a whee l, the torque must be checked as soon as possible with a torque wrench
-preferably by an authorized Audi
d e aler o r qua lifi ed wo rksho p.•
Low aspect ratio tires
You r A ud i is fac tory-eq uippe d w ith low aspect ra tio tire s. T hese tire s
have been thorough ly t ested and b een se lected specifica lly for your
mod el for thei r su p erb pe rf or manc e, r oad f eel an d ha nd ling under
a variety of driving con ditions . As k your authorized Audi d ealer for
m ore de ta ils.
The low aspect rat io o f th ese t ires is indicated by a numer al of 55 or
less in the t ire's size designation. The numeral rep resents the ratio
o f t he t ire's s idewa ll he ig ht in rel ati on to it s tread w idt h ex pressed
in percentage . Conventiona l tires have a height/width ratio of 60 or
mo re.
The performan ce of low -aspe ct-ratio tires is particularly sensitive to
improper inflation pressure . It is therefore important that low
aspect ratio tires are inflated to the specified pressure and that the
inflat ion pressure is regularly checked and ma intained. Tire pres­
sures should be checked at least once a month and always before a
long trip~
page 333, "Checking tire pressure" .
What you can do to avoid tire and rim damage L ow aspect ratio tires can be damaged mo re easily by impact with
po tho les, cu rbs, gull ies o r rid ges o n th e road, particular ly if the t ire
is underinf lated .
I n or der to mini mize th e occurrence of i mpac t da mag e to t he tires
of your vehicle, we recommend that you observe the fol lowing
pr ecaut ions :
• Always ma intain recom mended inflatio n pr essu res . C heck you r
ti re p ressu re eve ry 2,000 mi les (3,000 k m) and add a ir if neces sary .
• D rive carefully on roads with potho les, deep gullies or ridges.
T he impact from d riving th rough or ove r such obstac les can
da mage y our tires. I mpact with a cu rb m ay a lso cause damage to
your tire s. ..,
Vehicle care
I t •