2009 AUDI S8 tire size

-Select System s in the CAR menu .
- Selec t
Instrument cluster .
-Select Trip computer 1 or Trip computer 2 .
-Select, for examp le, Fuel range On to turn on the display
or
Off to turn the disp lay off.
All values in the single -trip or the total -trip memory can be reset to
zero simultaneously in MMI. In addition you can determine what
driving information from the trip computer should be shown in the
instrument cluster display. If one of the pieces of driver information
is turned off, that driver information will not be shown in the display .
The information will continue to be calcu lated by the trip computer
and can be turned back
on at any time. •
Tire pressure monitoring system
Applies t o vehi cle s: with n re pre ss ure moni toring sys te m
General notes I)
Each tire, including the spare (if provided}, should be checked
month ly when cold and inflated to the inflation pressure recom­
mended by the vehicle manufacturer on the vehicle placard or tire
inflation pressure label. (If your vehicle has tires of a different size
than the size indicated on the vehicle placard or tire inflation pres ­
sure label, you should determine the proper tire inflation pressure
for those tires.}
As an added safety feature, your vehicle has been equipped with a
tire pressure monitoring system (TPMSl that illuminates a low tire pressure tellta le when one or more of your tires is significantly
under-inflated . Accordingly, when the low tire pressure te lltale i llu ­
minates, you should stop and check your tires as soon as possible,
and inflate them to the proper pressure. Driving on a significantly
under -inflated tire causes the tire to overheat and can lead to tire
Controls and equip ­
ment
Dr ive r informat ion di spl ay
failure . Under -inflation also reduces fuel efficiency and tire tread
life, and may affect the vehicle's handling and s topping ability.
Please note that the TPMS is not a substitute for proper tire mainte ­
nance, and it is the driver 's responsibility to maintain correct tire
pressure, even if under-inflation has not reached the leve l to trigger
illumination of the TPMS low tire pressure te lltale.
Your vehic le has a lso been equipped with a TPMS malfunction indi­
cator to indicate when the system is not operating proper ly. The
TPMS ma lfunction indicator is combined w ith the low ti re p ressure
tel ltale . When the system detects a malfunction , the telltale wil l
flash for approximately one minute and then remain continuously
il luminated . This sequence will cont inue upon subsequent vehicle
start -ups as long as the malfunction exists.
When the ma lfunction indicator is illuminated, the system may not
be able to detect or signal low tire pressure as intended . TPMS
mal functions may occur for a variety of reasons, including the
insta llation of replacement or alternate tires or wheels on the
vehic le that prevent the TPMS from funct ioning properly. A lways
check the TPMS malfunction tellta le after replacing one or more
tires or whee ls on your vehicle to ensure that the replacement or
alternate tires and wheels allow the TPMS to continue to function
properly. •
Applies t o vehic les : w ith Tire press ure mon itoring sy stem
Introduction
The tire pressure monitoring system moni tors air pressure
in all four roa d wheels and the spare tire* while the
vehicle is moving.
As soon as the tire pressure monitoring system senses a significant loss of air pressure in one o r severa l tires, text messages and yellow
symbo ls appear in the instrument cluster display to alert the driver.
The L warni ng light in the instrument cluster comes on when the
tire is significantly underinflated
=> page 20. _,,
I • •

ll}Jl __ ln_ t _e_ ll-'"ig ...,_ e_ n_t _t_ e_ c_ h _ n_o _ l_o _,.g= y,_ __________________________________________ _
Winter tires
When driving in the winter, your vehicle with All Wheel Drive has an
advantage, even with regular tires. In winter road conditions it may be advisable to mount winter tires (or all -season tires) for improved
driveability and braking: these tires must be mounted on
all four
wheels.
See also ~ page 343, "Winter tires".
Tire chains
Where tire chains are mandatory on certain roads, this normally
also applies to vehicles with All Wheel Drive~
page 344, "Snow
chains".
Replacing wheels/tires
Vehicles with All Wheel Drive must always have tires of the same
size. Also avoid tires with different tread depths . For details see
page ~
page 338, "New tires and replacing tires and wheels".
Off-Road driving?
Your Audi does not have enough ground clearance to be used as an
off-road vehicle. It is therefore best to avoid rough tracks and
uneven terrain as much as possible. Also refer to~
page 281.
& WARNING
Always adjust your driving to road and traffic conditions. Do not
let the extra safety afforded by All Wheel Drive tempt you into
taking extra risks.
• Although the All Wheel Drive is very effective, always
remember that braking capacity is limited by tire traction. You
should therefore not drive at excessive speeds on icy or slippery
road surfaces.
• On wet road surfaces, be careful not to drive too fast because
the front wheels could begin to slide on top of the water (aqua­
planing).
If this should occur, you will have no warning from a
sudden increase in engine speed as with a front-wheel drive
vehicle. Always drive at speeds which are suited to the road condi­
tions - risk of crash. •
Energy management
Starting ability is opt:m·zed
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 conventional energy system is not driven for a
long period of time, the battery is discharged by idling current
consumers (e.g . immobilizer) . In certain circumstances it can result
in there being insufficient energy available to start the engine.
Intelligent energy management in your vehicle handles the distribu­
tion of electrical energy. Starting ability is markedly improved and
the life of the battery is extended.
Basically, energy management consists of
battery diagnosis, idling
current management
and dynamic energy management.
Battery diagnosis
Battery diagnosis continuously determines the state of the battery.
Sensors determine battery voltage, battery current and battery
temperature. This determines the current state of charge and the
power of the battery .
Idling current management
Idling current management reduces energy consumption while the
vehicle is standing. With the ignition switched off, it controls the
energy supply to the various electrical components . Data from
battery diagnosis is considered.
Depending on the battery's state of charge, individual consumers
are gradually turned off to prevent excessive discharge of the
battery and thus maintain starting capability.
Dynamic energy management
While the vehicle is being driven, dynamic energy management distributes the energy generated according to the needs of the indi-•

________________________________________________ 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 .

___ 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 •

-Tires and wheels
PW-------------------
Engine II Tire designation Tire pressure front Tire pressure rear
( displa ce-
normal load full load normal load
full load
ment in
liter) condition
al condition
conditional condition
PSI
I I kPA PSI
kPA PSI II kPA II PSI II kPA
12-cylinder
255/45 R18 99H All Season 36 250 38 260 32 220 32 220
6 .0 Individual
rear seats 255
/40 R19 100V XL All Season 41 41 280 36 250 36 250
255 /40 R19 100Y
XL High Performance
36 250
38 260 32
220 32 220
275 /35 R20 102Y
XL High Performance 38 41 280 35 2 40 4 4 300
12 -cylinder 255 /45 R18 99H All Season 36 250 36 250 32 220 32 220
6 .0
255/40 R19 100V XL All Season 41
280 41 280 36 250 36 250
255 /40 R19 100V
XL High Performance 36 250 36 250 32 2 20 32 220
275 /35 R20 102Y XL High Performance
38 260 41 280 35 240 44 300
XL = reinforced or extra load tire . It may also appear as xi , EXTRA LOAD , or RF on the tire sidewall .
al norm al l oad cond it ion => pag e 330.
The cor rect tire pressure for the spare wheel is located on a label
either on the driver 's side B -pillar o r inside the fue l fil ler flap .
Because technica l changes may be mad e to vehicle equipmen t
du ring the mo del year, always co mpare the tire si ze designa tion on
the tire pressure label on your vehicle with the tires on your vehicle .
Make sure t hat the t ire size info rmati on on t he veh icle labe l is the
same as the size of the tires on the vehicle . This is especially impor ­
tan t if the vehicle bel ongs t o some one e lse or you boug ht the
vehic le with different rims/tires or you bought the vehicle as a previ ­
ously owned ve hicle.
Reme mbe r, you r safety an d that of your passengers a ls o depe nds
on making sure tha t load limi ts are not exceed ed. Vehicle load
inc ludes everybody and everyt hin g in an d on th e vehicle . T h ese load
limits are technical ly referred to as the vehicle's Gross Vehicle
Weigh t Ra ting ("GVWR"). The Gro ss Axle Weigh t Ra tin g ("GAWR") is
the maximum load that can be applied at each of the vehicle's two axles
. The G ross Vehic le We ight Rating and the Gross Axle Weight
Rat ing are lis ted on the safety compliance sticker labe l located
either on the driver 's side 8 -pillar or on the inside of the fue l fi ller
fl ap . The ti re p ressure label on you r Aud i lists the maximum
combined weight of a ll of the occupants and luggage or other cargo
th at th e vehic le can carry . Fo r the location o f the t ire pressure labe l
=> page 330, fig. 274.
& WARNING
Overload ing a vehicle can cause loss of vehicle control , a crash or
other accident, serious personal injury , and even death .
• Carrying more weight than your vehicle was des igned to carry
will prevent the vehicle from handling properly and increase the
risk of a loss of vehicle control . .,_

___ 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