width AUDI S8 2008 Owners Manual

___ A_ u_ d_ i_s _i_d _e_ a_ s_ s
_ is_ t __________________________________________________ _
The detection ~ page 155, fig. 174 of the radar sensor detection
area is made up of:
• the approach area (light green area)
G), about 55 yards (50 m)
behind the vehic le, 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] Tips
S ide ass ist 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 wi ll be detected that are
not in the lane next
to the lane you are
using~ page 160 . •
Applies to vehicles: with side assist
Operation
Side assist 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 notable if you were
to change lanes, a signal light appears on the respective m irror.
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
vehic le is in your b lind spot and is detected by side assist . When the
difference in speed is greater, the signal light wil l not come on.•
Applies to vehi cles: with side assist
Informational and alert stage signals
Side assist has two signa l stages:
• the informational stage signal, and
• th e alert stage signal.
Side assist helps you by using the appropriate signa l stage,
depending on whether or not you have activated the turn signal,
and thus have indicated that you are or are not changing lanes.
Informational stage 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 lumination .
The brightness of the informationa l stage signa l 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.
When you look in the outside mirror, you can clearly see the infor­
mational stage signal.
Alert stage signal
When you ac tiva te the turn signal, and side assis t has detected a
vehic le in a notable location on that particular side, the signal light
on this side mirror flashes brightly. The repeated brief and bright
flashing of the alert stage signal reminds you to careful ly check
traffic to the rear in the outside mirror and over your shou lder, so
that you can safe ly complete the lane
change~ & in "Safety tips"
on page
161.
[ i] Tips
The brightness of the signal light on the outside mirrors can be
adjusted with the MMI
~ page 159. •

___ A_ u_ d_ i_s _i_d _e_ a_ s_ s
_ is_ t __________________________________________________ _
-Select Audi sid e ass is t.
-Select W arning l amp : brightn ess.
-Rotate the control knob to adjust the displayed bright -
ness of the signal l ight on the outside mirrors
=> page 159, fig. 180 .
Th e brightn ess o f th e signal light for both th e informational and
a lert stages is automatica lly adj usted to ambient light conditions. In
addition, you can adjust the
basic brightness separately, via the
brightness function
=> page 159, f ig. 180.
While mak ing the adjustment , the new br ig htness setting is
displayed briefly. The brightn ess disp layed is that of the informa ­
tiona l stage s ignal. The alert stage signal brightness is linked to the
in formational stag e signal brightness .
The infor mationa l stage signal br ightness should be adjusted so
that you notice the signa l illumination when you look in the outside
m irror, but not when you look forward through the windsh ield.
In very dark or light surround ings , the automat ic brightness setting
adjusts signal light brightness to maximum or minimum intensity ,
as needed . In circumstances such as these, you may not not ice any
change in the brightness on the outside m irror wh en adjusting the
basic brightness .
You may not notice the change until ligh ting conditions are normal
aga in .
[ i ] Tip s
• Side assist is not active wh en the basic brightness is adjusted .
The signal l ight comes on briefly to help you make the adjustment.
• Your settings are automatically s tored and assigned to the
remote contro l key being used. •
App lies to ve hicles: w ith s ide assis t
General information
Side assist has lim its and cannot detect vehicles under all road and
weather conditions. Please remember system limit ations and never
rely on the system, especia lly when:
• driving through
curves=> page 160,
• l anes are of different widths => page 160. •
Applies to ve hicles : w ith sid e as sist
When driving through curves
Side assist cannot detect vehic les in curves with a turning radius of
l ess than
218 yards (200 m) .
When driving through a curve , it is poss ib le that side assist may
register a vehicl e two lanes over, and the signal on the outside
m irror w ill light up .•
A pplies to vehicle s: w ith sid e ass is t
Lane width
w cl,
Fig . 18 1 L an es of a
norma l widt h are i n
d etec tion area

_________________________________________________ A
_ u_ d_ i _s _ i_d _e _ a_s_ s_ i_ s _t __ lJIII
Fig . 182 Narr ow lane s:
Si de ass is t m ay detec t
vehi cle s two la ne s
a w ay
Side assist's detection area is designed to cover lanes of standard
width to the left and r ight of your travel lane, depend ing on whethe r
you drive in the center of your lane or c loser to the edge .
I f you drive in narrow lanes, side assist's detection area may also
include other lanes - especially if you tend to dr ive on the edge of
your
lane~ fig . 182. Under these conditions, vehicles can also be
de tec ted tha t are two lanes away, and side ass ist then c ould switch
between the informational and warning stage signa ls.
When d riving in very wide lanes, vehicles in t he adjacent lane may
not be detected because they are not ins ide the detection area. •
Notes
Applies to vehicles: with side ass is t
Messages in instrument cluster display
If side assist turns off automatically, the indicator light on the
b utton wil l go out a nd you w ill see a message in the i nstrument
cluster disp lay :
Audi side a ssist not available : sen sor s pos sibly blocked
T he side assist sensors are bui lt into the rear bumper on the left and
r ight ( not visi ble on the
ou ts id e) ~ page 154, fig. 171 . To ensure t hat
you do not adverse ly affect the way side assist functions, foreign
Controls and equip­
ment
objects (such as stickers or bicyc le racks) should not be attached to
t he area on the rear bumper where the sens ors are loca ted. If s ide
assist functions are adversely affected, you will see this message in
the instrument cluster display. Remove anything that may be b locking the sensors .
I f no vehic le is detected for a longer period of time while driving,
s ide assist wil l also switch o ff automatica lly.
Audi side a ssist currently not available
If there is a temporary prob lem (such as the vehic le's battery charge
being low), side assist cannot be activated temporarily .
Audi side assis t : sy stem fault
Have t he system chec ked by an autho rized Audi dealer o r qualified
workshop. •
Applies to vehic les: with side assist
Safety tips
The side ass ist detec tion may be li mit ed when dr iv ing a round
narrow street corners, on hilly streets, and under poor weather
conditions.
I t is possible that the radar sensors may a ls o detec t other objects,
such as high or staggered guardrails.
Side ass ist does not measu re actual la ne w idth. 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 driv ing to the left or right of the center of a travel lane, it is
possible that vehicles wi ll be detected that are
not in the lane next
to the lane you are using.
& WARNING
• Improper relian ce on the side assi st system c an cau se colli ­
sions and serious personal injury:

Tires and wheels -
----------------
•
& WARNING (continued)
crashes and serious personal injuries . Have worn or damaged tires
replaced immediately.
• 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
low speed.
Glossary of tire and loading terminology
Accessory weight
means the combined weight (in excess of those standard items
which may be replaced) of automatic transmission, power steering,
power brakes, power windows, power seats, radio, and heater, to
the extent that these items are available as factory-installed equip­
ment (whether installed or not).
Aspect ratio means the ratio of the height to the width of the tire in percent.
Numb ers of 55 or lower indicate a low sidewall for improved
steering response and better overall handling on dry pavement.
Bead
means the part of the tire that is made of steel wires, wrapped or
reinforced by ply cords and that is shaped to fit the rim.
Bead separation
means a breakdown of the bond between components in the bead.
Cord
means the strands forming the plies in the tire.
& WARNING (continued)
• 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 loss of vehicle control.
• If you notice unusual vibration or if the vehicle pulls to one side
when driving, always stop as soon as it is safe to do so and check
the wheels and tires for damage.
•
Cold tire inflation pressure
means the tire pressure recommended by the vehicle manufacturer
for a tire of a designated size that has not been driven for more than
a couple of miles (kilometers) at low speeds in the three hour period
before the tire pressure is measured or adjusted.
Curb weight
means the weight of a motor vehicle with standard equipment
including the maximum capacity of fuel, oil, and coolant, air condi­
tioning and additional weight of optional equipment.
Extra load tire
means a tire design to operate at higher loads and at higher infla ­
tion pressures than the corresponding standard tire. Extra load tires
may be identified as
"XL", "xi", "EXTRA LOAD", or "RF" on the side ­
wall.
Gross Axle Weight Rating
("GAWR")
means the load-carrying capacity of a single axle system, measured
at the tire -ground interfaces.
Gross Vehicle Weight Rating
( " GVWR")
means the maximum total loaded weight of the vehicle.
Vehicle care

_L--_T_ ir_e_ s_ a_ n_d _ w_ h_ e_e _l_s _________________________________________________ _
Groove
means the space between two adjacent tread ribs.
L oa d r atin g (code)
means t he m aximum load that a t ire is rated to carry for a given
inf lation pressure . You may not find this information on a ll tires
because it is not required by law.
M ax imum l oad r ating
means t he load rating for a tire a t the maximum permissib le infla­
tion pressure for that tire.
Maximum l oaded v ehi cle wei ght
means the sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capaci ty weight, and
(d) Product ion options weight
M ax imum (p er mis sibl e) infl ati on pr essure
means the maximum cold i nflation pressure to wh ic h a t ire may be
inflated. Also cal led "maximum inflation pressure."
Normal occ upant we ight
means 150 lbs. (68 ki lograms) times the number of occupants
seated in the veh ic le up to the total seating capacity of your vehicle.
Oc cupant distributi on
means distribution of occupants in a vehicle .
Outer di ameter
means the overal l diameter of an inf lated new tire.
O verall width
means the linear distance between the exteriors of the sidewa lls of
an infla ted t ire, includ ing elevat ions due to labe ling, decorat ions, or
protective bands or ribs .
Ply
means a layer of rubber -coated para llel cords.
P rodu cti on opt ion s we ig ht
means the co mbined weight of those insta lled regular product ion
options weighing over 5 lbs. (2.3 kg) in excess of those standard
items which t hey replace, not previously considered in curb weight
or accessory weight, inc luding heavy duty brakes, ride levelers, roof
rack, heavy du ty bat tery, and special trim .
Rad ia l pl y tir e
means a pneumat ic t ire in wh ich t he ply cords that extend to the
beads are laid at substantially 90 degrees to the centerline of the
t read .
Recomm ended infl ation pres su re
see :::::> page 325, "Cold tire inflat ion pressure".
R einforc ed tir e
means a tire des ign to operate at higher loads and at higher infla­
tion pressures than the corresponding standard tire. Reinforced
t ires may be iden tified as
"XL", "xi", "EXTRA LOAD", or "RF" on the
sidewa ll.
Rim
means a metal support for a tire or a tire and tube assembly upon
whic h the t ire beads are seated.
Rim di ame ter
means nominal diameter of the bead seat. If you change your whee l
size, you wi ll have to purchase new tires to match the new rim diam ­
eter.
Rim siz e design ation
means rim diameter and width.
Rim w idth
means nominal distance between rim flanges .

1119...__T_ ir_e _ s_ a_ n
_ d_ w_ h_ e_ e_ls _________________________________________________ _
Incorrect wheel alignment
Incorrect wheel alignment can cause excess ive tire wea r, impairi ng
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, construc tion and tread type. F or details see
~ p age 273 .
& 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 indi cators .
• 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 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 speed s.
• 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
N ew t ires and wheels h ave t o be broke n in.
Fig . 2 76 T ir e specification code s on the sidewall of a tire
No .
G)
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 rat ing

Tires a nd wh eels -
----------------
•
0
©
U.S. DOT tire identification number
Sever snow cond itions
Ti re ply composition and materials used
Maximum load rating
Treadwear, traction and temperature grades
@ Maximum permissible inflation pressure
The tires and rims are essentia l parts of the vehicle 's design. The
tires and rims approved by Audi are special ly matched to the char­
acteristics of the vehic le and can make a major contribution to good
road hold ing and safe handling when in good cond ition and prop­
erly inf lated
=> .&, .
We recommend tha t all work on tires and wheels be performed by
an authorized Audi dea ler . They are familiar with recommended
procedures and have the necessary special too ls and spare parts as
we ll as the proper facilities for disposing of the old tires.
Authori zed Audi dea lers have the necessary information about tech ­
n ical requirements for insta lling or changing tires and rims.
R ep lac ing t ires and wh eels
Tires shou ld be replaced at least in pairs and not individual ly (for
examp le both front tires or both rear tires together).
Be sure to read and heed the informat ion to the tire pressure mon i­
toring
system => page 338.
Always buy replacement radial tires t hat 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 328.
Audi -approved specification tires are specially 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 328) lists specificat ions 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 -pil lar or
ins ide the fuel fi ller
flap( => page 328, fig. 273) lists the specifica­
tions of the original equipment tires installed on your vehicle at the
t ime it was manufactured.
Federa l law requires tire manufacturers to place standardized infor ­
mation on the sidewa ll of all
tires => page 336, fig . 276. This informa ­
tion identifies and describes the fundamental characteristics, the quality grade of the tire and a lso provides a tire identification
number for sa fety standard cert ificat ion and in case of a recall.
T ire s pec ificat ion s
Knowledge of tire specifications makes it easier to choose the
correct tires . Radial tires have the tire specifications marked on the
sidewall, for example :
255/45 R 18 99 H
This contains the fo llowing information:
P Indicates the tire is for passenger cars (where applicable)
255 Nominal tire width in mm of the tire from 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 rat ing code
H Speed rat ing letter code
XL (or "xi", "EXTRA LOAD" or "RF") indicates that the tire is a "Rein­
forced" or an "Extra Load" tire
M +S (or "M/S") Indicates tha t the tire has some mud and snow capa ­
bility
The tires could a lso have the information of direction of rotation
=> page 324.
Vehicle care

___ 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
on your vehicle (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.
• 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 compatib le with the tire pressure monitoring system.
Otherwise the system will register a malfunction 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.
For the sake of the environment
Dispose of o ld 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 336,
fig. 276.
For example: 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 wear
The tread wear grade is a comparative rating based on the wea r 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 upon the actua l condi­
tions of their use, however, and may depart significantly from the
n orm due to variations in driving habits, service practices and differ­
ences in road characteristics and climate .
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 contro lled conditions on specified government
t est surfaces o f asphalt and concrete. A tire marked C may have
poor traction performance
=:> & .
Temperature
The temperature grades are A (the highest), B, and C, representing
t he tire's resistance to the genera tion of 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=> &.
The 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
performance on the laboratory test whee l than the minimum
required by law.
~