2009 AUDI S8 tire pressure

___ ln_ t _e_ ll-'"ig ...,_ e_ n_t _t_ e_ c_ h _ n_o _ l_o _,.g= y,_ __________________________________________ _
& WARN ING (continued )
vehicle and have it towed to the nearest Aud i dealer or qualified
workshop.
;:a
Brake booster
The brake booster a dds ex tra braking power.
The bra ke booster works wit h vacuu m pressure w hich is created
only when the engine is running =>& .
& WARNING
• Never let the vehicle roll to a stop with the engine shut off .
• If the brake boo ster i s not wor king , for e xample when towing
your vehicle, or because the brake booster has somehow been
damaged , the brake pedal must be pre ssed considerably harder to
make up for the lack of booster as sistance. •
Functioning of Anti-Lock Brake System {ABS)
A BS prevents the wheels from l ocking up under braking.
The ABS contributes effective ly to vehicle contr ol since i t preven ts
t he whee ls from
locking whe n the brakes are appl ied. This mea ns
that the vehicle remains steerable and is less likely to skid .
With ABS you do not need to pump the brake. Ju st hold the brake
pedal down .
However, do no t ex pect the ABS to sho rten braking distance u nder
all circumstances. When drivin g on gravel or on new ly fallen snow
on top of icy surfaces, bra king distance may be even longer, there­
f ore, under these c ircu msta nces, it is especially importa nt that you
drive slow ly and with great care.
How the ABS system works
An au toma tic c heck is made when a s peed of about 4 mph (6 km/h)
is reached. When this happens, a pumping no ise can be heard.
I f an individual wheel begins to rotate too slowly in relation to
veh ic le speed and tends to lock, the ABS au tomat ically reduces
brake pressure to prevent that whee l from locking.
Th is au tomatic a djust ment pr oces s wi ll cause a
slight vibration o f
the brake peda l and some noises to alert you that vehicle speed
m ust be ada pted to e xisting road and traff ic conditio ns.
& WARNING
Although the ABS is very effective , alway s remember that braking
capability is limited by tire traction . Always adjust your driving
speed according to the road and traffi c conditions. Do not let the
extra safety afforded by the ABS tempt you into tak ing extra risks.
The ABS cannot overcome the laws of physics.
[ i ] Tips
• I f ABS is not functioning properly, a wa rning light will come on .
See=>
page 27.
• I f a faul t occurs in t he ABS, t he EDL is also n ot fu nctio ning . Th is
is indicated by the ABS warning light. •
Brake assistant
T he brak e assi stant i s designe d to ac hie ve th e optimu m
bra kin g eff ec t.
The bra ke assistant helps to increase the effective braking power
an d th us to achieve a shorter s top ping dis tan ce. If the dr iver
presses the brake pedal very quic kly, the brake assistant automati ­
c a lly bo osts t he braking force to the max imum level, up to th e point
where the anti -lock brake function (ABS) intervenes to stop the
whee ls from locking. You shou ld then keep the brake peda l pressed .,

Operating instructions
Max im um tra iler weight
A trailer for your vehicle is limited to a typical class 1 or class 2
trailer.
T ra ile r l oa d di stributio n
Be sure the load in the trailer is he ld securely in place to prevent it
from shifting forward, backward or sideways .
Never allo w a passe nger to r ide in a tr aile r~ & in "Driving instruc­
tions" .
Engin e c oolin g sys te m
Towing a trailer makes the eng ine work harder. It is important that
the cooling system's performance is up to the additiona l load. Make
sure that the coo ling system has enough fluid .
Tire pr ess ure
When towing a trailer, inflate the tires of your vehicle to the co ld tire
pressure listed under "Full load" on the labe l located either on the
driver's side B -pil lar (visible when the door is open) or inside the fuel
filler flap . Inflate trai ler tires to trai ler and tire manufacturers' spec­
ifications.
L ig ht s
The head light settings should be checked wit h the trai ler attached
before driving off. Check to make sure both vehicle and trai ler lights
are working properly .
Safe ty c ha in s
Be sure traile r safety chains are properly connected from the trailer
to the hitch on the vehicle. Leave enough slack in the chains to
perm it turning corners . When you i nsta ll safety chains, make sure
they will not drag on the road when you are driving.
T he chains should cross under the trailer tongue to prevent it from
dropping in case of separat ion from the hitch.
Controls and equip­
ment Safety first Vehicle operation
Tr
aile r t owing
0 Note
If you are going to tow a trai ler, you must activate the trailer opera­
tion mode ~
page 192, "Towing a Trailer". •
Driving instructions
Driving with a trailer always requires extra care and
consideration.
To obtain the best possible handling of veh icle and trailer,
please note t he following :
- Do not tow a loaded trailer when your car itself is not
loaded.
Be espec ia lly careful whe n passing other vehicles.
- Observe s peed limits .
Do not drive at the maximum permiss ible speed .
Always apply brakes ear ly.
Moni tor t he temperature ga uge.
Weight distr ibution
Towing a loaded trailer with an empty car results in a highly
unstable distr ibution of weight. If this cannot be avoided, drive at
very low speeds only to avoid the risk of losing steering control.
A "balanced" rig is easier to operate and control. This means that
the tow vehicle should be loaded to the extent possible and perm is ­
s ib le, while keeping the trailer as light as possib le under the circum ­
stances . Whenever possible, transfe r so me cargo to t he luggage
compartment of the tow vehicle whi le observing tongue load
requirements and vehicle loading considera tions . .,
Vehicle care Do-it-yourself service Technical data

-~_T_ ir_e_ s_ a_ n_d _ w_ h_ e_e _l_s _________________________________________________ _
Tires and wheels
Tires
General notes
Tires may be the least appreciated and most abused parts
of a motor vehicle.
Tires may be the least appreciated and most abused parts of a
motor vehicle. Tires are, however, one of the most important parts
of a vehicle, particu larly considering the comparatively small patch
of rubber on each tire that assures that all -important contact
between you, your vehic le and the road.
Maintaining the correct tire pressure, making sure that your vehicle
and its tires do not have to carry more weight than they can safely
handle, avoiding damage from road hazards and regularly inspecting tires for damage inc luding cuts, s lashes irregular wear
and overa ll condition are the most important things that you can do
to help avoid sudden tire failure including tread separation and
blowouts.
A vo iding d am age
If you have to drive over a curb or similar obstac le, drive very slowly
and as close as possible at a right angle to the curb.
A lways keep chemica ls including grease, oi l, gaso line and brake
fluid off the tires.
Inspect the ti res regu larly for damage (cuts, cracks or b listers, etc.l .
Remove any foreign bodies embedded in the treads.
Storing tir es
Mark tires when you remove them to indicate the direction of rota ­
t ion. This ensures you to be able to mount them correctly when you
reinstal l them. When removed, the wheels or tires shou
ld be stored in a coo l, dry
and preferably dark place.
S tore tires in a vertical pos it ion if they a re not mounted on r ims, in
a horizonta l position if they are mounted on rims.
New tir es
New tires have to be broken in=>&.
The tread depth of new ti res may vary, according to the type and
make of tire and the tread pattern.
H idd en damage
Damage to tires and rims is often not readily visible. If you notice
unusual vibration or the vehicle pu lls to one s ide, this may indicate
that one of the tires has been damaged . The tires must be checked
immediately by an authorized Audi dealer or qualified workshop .
Unidire cti ona l t ires
A unidirectional tire can be identif ied by arrows on the sidewa ll, that
point in the direction the tire is designed to rotate . You must fo llow
t he specified directio n of rotation . This is necessary s o that these
tires can develop their optimum characteristics regarding grip, road noise, wear and hydrop laning resistance . For more information
=>
page 359.
& WARNING
New t ires o r ti re s th at a re old , worn or d am aged cann ot pro vid e
maximum cont rol and braking ability .
• New tires te nd to be slippery and mu st be bro ken in . To redu ce
the ri sk o f lo sin g co ntro l, a collis ion and serious per sonal injurie s,
dri ve w ith special care f or the fi rst 350 m ile s ( 560 km l.
• Driving w ith w orn or damaged tire s can lead to lo ss of control ,
sudd en tir e fa ilure , inc ludi ng a blowout a nd sudden defl atio n, ..,_

________________________________________________ T_ i _r_e _s_ a_n_ d_ w_ h_ e_e _ l_s __ ,n
•
& W ARNING (continu ed )
crashes and serious personal in jur ies . Have worn or da maged t ires
replaced immediately .
• Tires age even if they are not being u sed and can fail suddenly ,
especially at high speeds. T ires that are more than 6 years old can
only be used in an emergency and then w ith special care and at
low speed.
Glossary of tire and loading terminology
Accessory weight
means the co mbined we ig ht ( in excess o f those sta nda rd items
which may be rep laced) of automatic transmission, power steering,
power brakes, power w indows, powe r seats, rad io, a nd heater, to
the extent that these items are avai lab le as factory-installed equip­
m ent (w hether insta lled or not).
Aspect ratio means t he ratio o f th e height to t he w idt h of the tire in perce nt.
N umbers of 55 or lower indicate a low sidewa ll for improved
steer ing respo nse and b ette r overall ha ndl ing on dry pave ment.
Bead
means the part of the tire that is made of stee l wires, wrapped or
reinforced by ply cords and that is shaped to fit the rim.
Bead separation
means a breakdow n of the bond be tween co mponents i n the bead.
Cord
m eans the strands fo rmi ng the plies in the ti re.
& W ARNING (continued )
• Never mount used tires on your vehicle if you are not sure of
their "previous history. " Old used t ire s may ha ve been damaged
even though the damage cannot be seen that can lead to sudden
tire failure and lo ss of vehicle control.
• If you noti ce 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
mea ns t he ti re pressure reco mm ended by the ve hicle ma nufacturer
for a tire of a designated size that has not been d riven for more tha n
a cou ple o f miles (k ilometers) at low speeds in t he t hre e ho ur per iod
before the tire pressure is measured or ad justed .
Curb weight
means the weight of a moto r vehic le with standard equipment
i nc lud ing the max imu m capac ity o f fue l, o il, and coola nt, a ir c ond i­
tioning and additiona l weight of optional equipment.
Extra load tire
means a tire des ign to operate at higher loads and at highe r infla ­
tion pressures than the corresponding standard tire. Extra load tires
may be identified as "XL", "xi", "EXTRA LOAD", or "RF" on the side ­
wa ll.
Gross Axle Weight Rating ("GAWR ")
means the load -carrying capacity of a sing le ax le system, measured
at the ti re -ground interfaces.
Gross Vehicle Weight Rating ("GVWR "l
mea ns the ma ximum tot al l oade d weigh t of the vehicle.
Vehicle care
I t •

-~_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 .

Tires a nd wh eels 111111 ________________________________ ::..:..:....::.=.....::.:..:..:..::..:___:__ _ ___:,___
•
Sidewa ll
means that portion of a tire between the tread and bead.
Speed ra ting means the speed at which a t ire is designed to be driven for
extended periods of time. The ratings range from 93 mph (150 km/h)
t o 186 mph (298 km/h) =>
page 340. You may not find this informa ­
tion on all tires because it is not required by law.
The speed rating letter code, where applicab le, is molded on the tire
sidewa ll and indicates the maximum perm issible road speeds=>
&
in "Winter tires" on page 343.
T ire pre ssu re m onit orin g sys te m *
means a system that detects when one or more of a vehicle's tires
are under inflated and illuminates a low tire pressure warning tell­
tale.
Tre ad
means that portion of a tire that comes into contact with the road .
Tread sepa ra ti on
means pu lling away of the tread from the tire carcass.
Tr ea dw ear indi cato rs ( TW I)
means the projections with in the principal grooves designed to give
a visual indication of the degrees of wear of the tread . See
~ page 337, "Tread Wear Indicator (TWI)" for more information on
measuring tire wear.
U ni form Tire Q ua lity G radin g
is a tire information system developed by the United States National
Highway Traffic Safety Administration (N HTSA) that is designed to
help buyers make re lative comparisons among tires. The UTQG is
not a safety rating and not a guarantee that a tire will last for a
prescribed number of miles (kilometers) or perform in a certain way .
I t simply gives tire buyers additional information to combine with
other considerations, such as price, brand loya lty and dealer recom -mendations
. Under UTQG, tires are graded by the tire manufac ­
t urers in three areas : treadwear, traction, and temperature res is ­
tance. The UTQG information on the tires, molded into the sidewal ls .
U .S . DOT Tir e Identifi cation Numb er (TIN )
This is the tire's "ser ia l number" It begins with the letters "DOT" and
indicates that the tire meets a ll federa l standards . The next two
numbers or letters indicate t he plant where it was manufact ured,
and the last four numbers represent the week and year of manufac­
ture. For example,
DOT ... 2 20 7 ...
means that the tire was produced in the 22th 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 reca ll.
V ehi cle ca pac ity w eig ht
means the rated cargo and luggage load plus 150 lbs . (68 kilograms)
times the vehicle's total seating capacity as listed on the label
located either on the d river's side 8 -pillar or on the inside of the fuel
filler flap.
V eh icle max imum load on the tire
means that load on an individual tire that is determined by distrib­
uting t o each ax le its share of the max imum loaded vehic le weight
and dividing by two.
V ehicle normal load on the tire
means that load on an individual tire that is determined by distrib­
uting t o each ax le its share of the curb weight, accessory weig ht,
and normal occupant weight (distributed in accordance with table
below =>
page 330) and dividing by two . _.,
Vehicle care I t •

___ T_ i_ r_e _s_ a_ n_ d_ w_ h_ e_ e _ ls _________________________________________________ _
Occupant loading and distribution for vehicle normal load for various designated seating capacities
Designated seating capacity , num­
ber of occupants
4
5
Cold tire inflation pressure
Vehicle no rmal load, number of
oc cupants
2
3
Occupant distribution in a normally
loaded vehicl e
2 in front
2 in front, 1 in b ack sea t
Tire pressure affects the overall handling, performance and safety of a vehicle.
Fig. 274 Tire pressure
label: located either on
driver 's side B-pillar or
inside the fuel filler flap
T IRE AND LOADING INFORMATION
T IRE SIZE COLD TIRE PRESS URE
FR ONT -KPa, - PSI
REAR -KPa, - PSI
I.:: SPARE -KPa, -PSI Fig . 275 Tire pressure
label
Maintaining proper tire pressure is one of the most important
things you can do to help avoid sudden tire failure. Underinflated
tires are a major cause of sudden tire failure. Keeping tires at the
right pressure is also important for safe and responsive vehicle
handling, traction, braking and load carrying. Tire pressures are
particularly important when the vehicle is being driven at higher
speeds, and then especially when heavily loaded even within the
permissible load-carrying capacities approved for your vehicle.
The recommended tire pressures for your Audi depend on the kind
of tires on your vehicle and the number of passengers and/or
amount of luggage you will be transporting.
•
Tire pressure generally refers to the amount of air in a tire that it
needs it to do its job and safely carry the combined load of the entire
vehicle and its contents . Tire pressure is measured in kilopascals
(kPa), the international measuring unit and in pounds per square
inch (PSI). Tire pressure is based in part on the vehicle's design and
load limit -the greatest amount of weight that the vehicle can carry
safely and the tire size. The proper tire pressure is frequently
referred to as the "recommended cold tire inflation pressure ." Air in
the tires expands when the tire heats up because of internal friction
when it flexes in use. The tire pressure is higher when the tire has
warmed up than when it is "cold." It is the inflation pressure in a
"cold" tire that counts. Therefore, you should never let air out of a
warm tire to match "cold tire inflation pressure " recommendations .
The tires would then be underinflated and could fail suddenly. On
USA vehicles, the tire pressure label is located on the driver's
side 8-pillar . On Canada vehicles, the tire pressure label is located
either on the driver's side 8 -pillar or inside the fuel filler flap . The tire
i.,.

Tires and wheels -________________ w-.
•
pressure label lists the recommended cold tire inflation pressures
for the vehicle at its maximum capacity weight and tires that were
on your vehicle at the time it was manufactured.
If you wish to improve comfort when operating the vehicle at
normal load (up to 3 occupants), you can adjust tire pressures to
those specified for normal vehicle load. Before operating the vehicle
at maximum load , you must increase the tire pressures to those
specified for maximum vehicle load
=> &.
Bear in mind that the tire pressure monitoring system* can only
monitor the tire pressures you have stored. The system does not
recognize the load condition of your vehicle .
The effec tiveness of the tire pressure mon itoring system* will be
impaired if you store normal load pressures but then operate the
vehicle at its maximum load=>&. See the
illustration=>
page 330, fig. 274 for the location of the label
either o n driver's side 8-pillar or inside the fuel filler flap (color of
the actual label and exact location on the vehicle will vary slight ly).
Note that the following tab le is accurate at the time of going to
press and is subject to change. In the event of discrepancies, the t ire
pressure label (On USA vehicles, the tire pressure label is located on
the driver's side 8-pillar. On Canada vehicles, the tire pressure label
is located either on the driver 's side 8-pillar or inside the fuel fil ler
flap) always takes precedence.
The table below lists the recommended cold tire inflation pressures
for the Audi mode l covered by your Owner's Literature at the
vehicle's capacity weight and the tire sizes installed on the respec­
tive models as original equipment, or as a factory option.
Engine
(displace­
ment in
liter) Tire designation
Tire pressure front Tire pressure rear
8-cylinder
4.2
8-cylinder
4 .2 L 255/45 R18 99H All Season
255/40 R19100V
XL All Season
255/40 R19
1 00Y XL High Performance
275/35 R20 102Y XL High Performance
255/45 R18 99H All Season
255/40 R19 100V XL All Season
255/40 R19 1 00Y XL High Performance
275/35 R20 102Y XL High Performance
normal load conditional
kPA
33 230
36 250
33 230
38 260 33 230
36 250
33 230
38 260
full load
condit ion
PSI
33 230
38 260
33 230
41 280
35 240
38 260
35 240
41 280
Vehicle care
normal load full load
conditional condition
kPA PSI kPA
30
210
33 230
33 230 36 250
30 210 33 230
35 240
44 300
30 210 33 230
33 230 36 250
30 210
33 230
35 240 44 300
I t •