2008 AUDI S8 Owners Manual

Tires and wheels -
-----------------'
Tire service life
The service life of tires depends on a lot of different things
including proper installation and balancing, correct tire
pressure and driving style .
Tread Wear Ind icator (TWI)
Fig. 274 Tire tread:
tread wear indicators
(TWII
Fig . 275 Rotating tires
for more even wear
The origina l tires on your vehic le have 1/16 inch (1.6 mm) high "wear
indicators"::::, fig. 274 running across the tread. Depending on the
make, there will be six to eight of them evenly placed around the
tire. Marks on the tire sidewall (for example
"TWI" or other symbols)
indicate the positions of the tread wear indicators. Worn tires must
be rep laced. Different figures may apply in other
countries::::, &-
Tire pressure
Incorrect tire pressure causes premature wear and can cause
sudden tire blow-out. For this reason, tire pressure must be checked
at least once a
month ::::, page 331.
Driving style
Driving fast around curves, heavy accele ration and hard braking
increase tire wear .
Rotating tires for more even wear
For all four tires on your vehicle to have the same service life, we
recommend that the front and rear tires are rotated according to the
tire manufacturer's suggested tire rotation intervals. Please
remember the following:
• Tire rotation intervals may differ from the vehicle service inter­
vals outlined in your Warranty
& Maintenance booklet.
• The longer one tire is used in one location on the vehicle, the
more it wears at certain points; therefore, we recommend that you
follow the tire manufacturer 's suggested tire rotation intervals .
• Vehicles with front-wheel drive experience more tread wear on
the front wheels compared to all -wheel drive (quattro®l .
• Please rotate tires as shown
~ fig. 275.
• Extra care must be taken when rotating direction -specific tires
::::, page 357.
Wheel balancing
The wheels on new vehicles are balanced. However, various situa ­
tions during everyday driving can cause them to become unbal ­
anced, resu lting in vibrations you can usually feel through the
steering wheel.
Unbalanced wheels must be rebalanced to avoid excessive wear on
steering, suspension and tires. A whee l must also be rebalanced
when a new tire is insta lled.
...
Vehic le care I I Technical data

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 _______________________________________________ _
Tire ma nufact uring d ate
The manufacturing date is a lso indicated on the t ire sidewa ll
(possib ly on ly on the inner side of the wheel):
"DOT ... 2207 ...
" means, for example, the tire was produced in the
22nd week of 2007.
Sp eed ratin g (lett er code )
The speed rating letter code on the whee ls indicates the maximum
permissible road speeds =>
& in "Winter tires" on page 341.
P up to 93 mph (150 km/h)
Q up to 99 mph (158 km/h)
R up to 106 mph (170 km/h)
S upto110mph(180km/h)
T upto118mph(190km/ 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)2>
Z over 149 mph (240 km/h)2>
W up to 168 mph (270 km/h)21
Y up to 186 mph (298 km/ h)21
Your vehicle is normally factory equipped with tires, which possess
excel lent driving characteristics and give your Audi opt imum
driving comfort . An e lectronic speed
limiter=> page 28wil l norma lly
prevent your vehicle from going faster t han the tire speed rating
=> & .
U.S . D OT T ire Iden tifi cation Number (TIN ) and tire
m anuf actur e date
This is the tire's "seria l num ber" . It beg ins with t he 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 represent the week and year of manufac-
2 1 For tires with a maximum speed capab il ity over 149 mph (240 km/h), ti re
manufacturers somet imes use the lett ers "ZR."
ture . For example, the numbers 2207 mean the tire was produced in
t he 22nd
week of 2007 . The other numbers are marketing codes that
may or may not be used by the tire manufacturer . This information
is used to contact consumers if a tire defect requires a recall.
T ire p ly co mpos ition and mate ria ls used
The number of plies indicates the number of layers of rubber -coated
fabric in the tire . In genera l, the greater the number of p lies, the
more weight a tire can support. Tire manufacturers also must ind i­
cate the materials in the tire, which include steel, ny lon, polyester,
and others.
M ax imum Lo ad R ating
T his number indicates the maximum load in kilograms and pounds
that can be carried by the tire.
Tire quali ty grading f or treadwe ar, t rac tion , and
t e mp era tu re resis ta nce
Tread wea r, traction and temperature
grades => page 340.
M ax imum P ermi ssible Infl atio n Press ure
T his number is the greatest amount of air pressure that should ever
be put in the tire under norma l driving conditions.
Repl acing tir es o r rim s on vehi cles e quipp ed w ith tire
pr ess ur e monit orin g sy st em
T he wheels on your vehicle are equipped with a sensor which
constantly monitors the air pressure inside the tire , and then trans ­
m its this information to the tire pressure mon itoring system. If you
are going to replace the whee l rims on your vehicle, make sure the
n ew rims also have t hese sensors. The sensors mus t be compa tible
with the tire pressure monitoring system on your vehicle .
I f you instal l rims, which do not have the sensors, or have sensors
whic h are not compatible, then the t ire pressure monitoring system
wi ll not work properly. In this case, the tire pressure monitoring
system would not be ab le to mon itor the tire pressure or warn you
if it is necessary . .,_

________________________________________________ T_ i
_ r_e _s_ a_n_ d_ w_ h_ e_e _ l_s __ l'III
•
• T he batt ery inside of the tire pressure sensor has a l imited
s er vice l ife.
• Al ways drive with the va lve stem ca ps sec ure ly m ounted. We
r ec om mend u sin g fa ctor y in sta lle d v alv e stem caps. Ask your autho­
rized Audi d ealer to replac e lost valve stem caps .
T he in stalla tio n of replacement ti res with steel cord body plies i n
th e tire s id ewal l may cause malfunct ion of the tire pressure moni ­
toring sy ste m, and is not recommended (c ord mate ria l infor mation
i n mo lded on the tire s idewa ll).
Al ways check your tir e pressure monitor ing system indicator after
r eplac ing on e o r m ore tire s on y our vehi cle. If the tire pressu re
monitorin g system indicator flashes, or is on, your system is not
w orki ng pr ope rly. You r rep lace ment tir e mi ght be in co m pati ble w ith
your t ire pr essure monitoring system, or some component of the
t ir e pr ess ure m oni to ring sys te m m ay be damaged .
& 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 wheel bolts that meet the specifica­
tions of original factory -installed tires or other combinations that
have been specifically approved by the vehi cle manufacturer .
• Tires age even if they are not being used and can fail suddenly,
espe cially 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 loss of vehicle control.
• All four wheels must be fitted with radial tires of the same type ,
size (rolling cir cumference ) and the same tread pattern . Driving
&, WARNING (continued )
with different tires reduces vehicle 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
normal road wheel as soon as safely possible.
• 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 underinflated.
• For techni cal reasons it is not always possible to use wheels
from other vehicles -in some cases not even wheels from the
same vehicle model.
• If you install wheel trim discs on the vehicle wheels , make sure
that the air flow to the brakes is not blocked . Reduced airflow to
the brakes can them to overheat , increasing stopping distances
and causing a collision.
• Run flat tires may only be used on vehicles that were equipped
with them at the factory . The vehicle must have a chassis designed
for run flat tires and a factory-installed tire pressure monitoring
system that indicates a loss of tire pressure. Incorrect use of run
flat tires can lead to vehicle damage or accidents . Check with an
authorized 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 . Mixing tire types is not permitted.
0 Note
• Fo r tec hnica l reaso ns, i t is not gene rally p oss ibl e to use the
whee l rims from other vehicles . T his can hold true for wheels of t he
sa me v ehicl e typ e.
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.
~