2015 AUDI S8 wheel size

156 Airbag sys te m
- The Advanced A irbag System can deploy
in accordance with the "low risk" opt ion
under the U.S. Federa l Standard if a child
that is heavier than the typical one-year
old child is on the front passenger seat
and the other cond itions for airbag de­
ployme nt are met.
- Acc ident statist ics have shown that chi l­
dren are generally safer in the rea r seat
area than in the front seating posit io n.
- For their own safety, all children, espe­
cially 12 yea rs and younger, sho uld a l­
w ays ride in the back pro perly rest rained
for their age an d size.
Advanced front airbag system
Your veh icle is eq uipped wit h a front Advanced
Airbag System in compliance with United
States Federal Motor Vehicle Saf ety Standard
208 as applicab le at the time your vehicle was
manufactured.
The front Advanced Airbag System supp le­
ments the safety belts to provide addit iona l
protection for the drive r's and front passeng ­
er's heads and upper bodies in frontal crashes .
The airbags inflate only in frontal impacts
when the vehicle dece lerat io n is high enough .
The front Advanced Airbag System for the
front seat occupants is not a substitute fo r
your safety belts. Rather, it is part of t he over­
all occupa nt restraint system in your ve hicle.
A lways remember that the airbag system can
on ly help to protect you , if you are s itting up­
r ight, wearing yo ur safety belt and wea ring it
p roperly . This is w hy you and yo ur passenge rs
must always be properly restrained , not just
beca use the law requires you to be.
The Advanced Airbag System in your veh icle
h as been cer tified to meet the " low r is k " re­
qu irements for 3 and 6 year -o ld children on
the passenger side and very small adu lts on
the driv er side. The low risk deployment crite ­
ria are intended to he lp red uce the risk of in­
jury through interaction with the front airbag that can occur, fo r example, by be ing too close to the steering wheel and instrument
pane
l when the airbag inflates .
In add ition, the system has been certified to
comply wi th the "s uppression" re qu iremen ts
of the Sa fe ty Standard , to turn
off the front
airbag for infants 12 months o ld and younger
who are rest rained on the front passenger
seat in child restraints that are listed in the Standard
¢ page 176, Child restraints and
Advanced Airbags .
"Suppression" requires the front a irbag on the
passenger side to be tu rned
off if:
- a child up to abo ut one year o f age is re ­
strained on the front passenger seat i n one
of the rear-fac ing or forward -facing infant
restraints listed in Federal Motor Vehicle
Safety Standard
208 with which the Ad­
vanced Airbag System in your vehicle was
cert ified . For a listing of the ch ild res traints
that were used to certify you r vehicle 's com­
plia nce w it h t he US Safety Standa rd
¢ page 176,
-we ight less than a threshold level stored in
the co ntrol uni t is de te cted on the fron t pas­
senger seat.
When a person is detected on the front pas­ senger seat, weighing more than t he total
we ight of a ch ild tha t is abou t 1 year old re ­
stra ined in one of the rear-fac ing o r forward­
f acing infant res traints ( listed in Fede ral Mo­
tor Vehicle Safety Standar d
208 with which
the Advanced Airbag System in yo ur vehicle
was certif ied), the front airbag on the passen­
ger side may or may not deploy.
The
PASSENGER AIR BAG OFF light comes on
when the electronic contro l unit detects a to­
ta l we ight on the front passenger seat that re ­
quires t he front airbag to be t urned
off. If the
PASSENGER AIR BAG OFF light does not
come on, the front a irbag on the passenger
s ide has not been t urned
off by the cont ro l
u ni t and ca n dep loy if the control un it senses
an impact that meets the cond itions store d in
i ts memory.
If the total weight on the fro nt passenge r
seat is more than that of a typ ical 1 yea r-old , ..,_

.... N .... N
0 J:
-st: .... \!) 1.1"1
.... 1.1"1 ,-0
-Always install rear-facing child safety
seats on the rear seat.
- If you must install a rearward facing
child safety seat on the front passenger
seat in exceptional circumstances and
the
PASSENGER AIR BAG OFF light does
not come on and stay on, immediately
install the rear-facing child safety seat in
a rear seating position and have the air­
bag system inspected immediately by
your Audi dealer.
_& WARNING
If, in exceptional circumstances, you must
install a forward-facing child restraint on
the front passenger's seat:
- Always make sure the forward-facing
seat has been designed and certified by its manufacturer for use on a front seat
with a passenger front and side airbag.
- Always follow the manufacturer's in­
structions provided with the child safety
seat or carrier.
- Always move the passenger seat into its
rearmost position in the seat's fore and
aft adjustment range, as far away from
the airbag as possible before installing
the child restraint. The backrest must be adjusted to an upright position .
- Always make sure that the
PASSENGER
AIR BAG OFF
light comes on and stays
on all the time whenever the ignition is
switched on.
(D Tips
Always replace child restraints that were
installed in a vehicle during a crash. Dam­
age to a child restraint that is not visible
could cause it to fail in another collision
situation.
Advanced front airbag system and children
Your vehicle is equipped with a front "Ad­
vanced Airbag System" in compliance with United States Federal Motor Vehicle Safety
Child Safety 175
Standard (FMVSS) 208 as applicable at the
time your vehicle was manufactured.
The Advanced Airbag system in your vehicle
has been certified to meet the "low-risk" re­
quirements for 3- and 6-year old children on
the passenger side and small adults on the driver side. The low risk deployment criteria
are intended to reduce the risk of injury
through interaction with the airbag that can
occur, for example, by being too close to the
steering wheel and instrument panel when
the airbag inflates . In addition, the system
has been certified to comply with the "sup­
pression" requirements of the Safety Stand­
ard, to turn off the front airbag for infants up
to 12 months who are restrained on the front
passenger seat in child restraints that are list­
ed in the Standard.
Even though your vehicle is equipped with an
Advanced Airbag system, all children, espe­ cially those 12 years and younger, should al­
ways ride in the back seat properly restrained
for their age and si ze. The airbag on the pas­
senger side makes the front seat a potentially dangerous place for a child to ride . The front
seat is not the safest place for a child in a for­
ward-facing child safety seat. It can be a very
dangerous place for an infant or a larger child
in a rearward-facing seat .
Advanced Airbags and the weight­
sensing mat in the front seat
The Advanced Airbag System in your vehicle
detects the presence of an infant or child in a
child restraint on the front passenger seat us­
ing the weight -sensing mat in the seat cush­
ion and the sensor below the safety belt latch
on the front passenger seat that measures the
tension on the safety belt.
The weight -sensing mat measures total
weight of the child and the child safety seat
and a child blanket on the front passenger seat. The weight on the front passenger seat
is related to the design of the child restraint
and its "footprint", the size and shape of the
bottom of the child restraint as it sits on the ..,.
•
•

202 Intelligent technology
Driving with your
quattro
With All Wheel Drive, all four wheels are driv­
en .
General inform ation
With All Wheel Drive, power is distributed to
all four wheels . This happens automatically
depending on your driving style and the road
conditions at the time . See also
c:;; page 197.
With the sport differential*, power d istribu­
tion to the rear wheels is variable and can be
adjusted with Audi d rive select*
c:;; page 108.
Always read and follow safety precautions
¢ .&,.
Winter tires
When driving in the winter , your vehicle with
A ll Wheel Drive has an advantage, even with
regular tir es. In winter road conditions it may
be advisable to mount winter tires (or all-sea­
son tires) for improved driveability and brak­ ing: these tires must be mounted on
all four
wheels.
See also ¢ page 260, Winter tires.
Snow chains
Where snow chains are mandatory on certa in
roads, this normally a lso applies to vehicles
with A ll Wheel Drive
c:;, page 261, Snow
chains .
Replacing wheels/tires
Vehicles with All Wheel Dr ive must always
have tires of the same size. Also avoid ti res
with different tread depths. For details see
page
c:;, page 256, New tires and replacing
tires and wheels .
Off-Road driving?
Your Audi does not have enough ground clear­
ance to be used as an off-road vehicle. It is
therefore best to avoid rough tracks and un ­
even terrain as much as possible. Also refer to
c:;; page207.
A WARNING
Always adjust your driving to road and traf­
f ic 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 ef­
fective, always remember that braking
capacity is lim ited 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
(aquaplaning) . If this should occur, you
will have no warning from a sudden in­
crease in eng ine speed as with a front­
wheel drive vehicle. Always drive at speeds which are suited to the road con­
ditions - risk of crash .
Energy management
Starting ability is optimized
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 conventiona l ene rgy system
is not driven for a long period of time, the bat­
tery is discharged by idling current consumers
(e .g. immobilizer). In certain circumstances it
can resu lt in there being insufficient energy
available to start the engine .
Intelligent energy management in your vehi­
cle handles the distribution of e lectrica l ener­
gy. Starting ability is markedly improved and
the life of the battery is extended.
Basically, energy management consists of
battery diagnosis , idling current manage­
ment
and dynamic energy management.
Battery diagnosis
Battery diagnosis continuously determines
the state of the battery. Sensors determine
battery voltage, battery current and battery ..,.

24 6 T ire s and whee ls
- Never mount used tires on yo ur vehicle if
you are not sure of their "previous histo­
ry." Old used tires may have been dam­
aged 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, al­
ways stop as soon as it is safe to do so and check the wheels and tires for dam­
age.
(D Note
- Please note that summer and winter
tires are designed for the cond itions that
a re typ ica l in those seasons. Aud i recom­
mends using w inter t ires d uring the win-
Glossary of tire and loading terminology
Accessory weight
means t he comb ined weight (in excess of
those standard items which may be rep laced)
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 t he ratio of the height to the width of
the tire in percent. Numbers of 55 or lower in­
d icate a low sidewall for improved steer ing re­
sponse and better overall handling on dry pavement .
Bead
means the pa rt of the tire t hat is made of
steel wires, wrapped or reinforced by ply cords
and that is shaped to fit the r im.
Bead separation
means a breakdown of the bond between
components in the bead.
Cord
means t he strands forming the plies in the
tire. ter months.
Low tempe ratu res signifi­
cantly decrease the elasticity of summer
tires, which affects traction and braking ability. If summer tires are used in very
co ld temperatures, cracks can form on
the tread bars, resu lting in permanent
tire damage that can cause loud driving noise and unbalanced tires. Aud i is not
responsib le for this type of damage.
- Burn ished, polished or chromed rims
must not be used in winter weather. The
surface of the rims does not have suff i­
c ien t corrosion protect io n for this and
cou ld be pe rmanently damaged by road
salt or simi lar substances. This damage
is not covered by war ranty.
Cold tire inflat ion pre ssure
means the t ire press ure recommended by the
vehicle manufacturer for a tire o f a des ignated
size that has not been driven for more than a
coup le of miles (ki lometers) at low speeds in
the three hour period before the tire press ure
is measured or adjusted.
Curb weight
means the weight of a motor vehicle w ith
standard equipment including the maximum
capacity of fuel, o il, and coolant, air cond i­
tion ing and additional weight of optiona l
equipment.
E x tra load tire
means a tire design to operate at higher loads
and at higher inflation pressures than the cor­
responding standard tire. Extra load tires may
be identified as "XL", "xl", "EXTRA LOAD", or
"RF" on the sidewall.
Gross A xle Weight Rating ("GAWR ")
means the load-carrying capacity of a single
axle system, measured at the tire-ground in -
terfaces.
IJ>,

,....,
N ,....,
N
0 J:
'SI: ,...., \!) 1.1"1 ,...., 1.1"1 ,....,
Tires and wheels 24 7
Gross Vehicle Weight Rating ("GVWR") Ply
means the maximum total loaded weight of
the vehicle .
Groove
means the space between two adjacent tread
ri bs.
Load rating (code)
means the maximum load that a tire is rated
to carry for a given inflat ion pressure . You
may not find this informat ion on all tires be­
cause it is not requ ired by law.
Maximum load rating
means the load rating for a t ire at the max i­
mum permissible inflation pressure for that
tire .
Maximum loaded vehicle weight
means the sum of:
(a) Curb weight
(b) Accesso ry weight
(c) Vehicle capacity weight, and
(d) Production opt ions we ight
Maximum (permissible) inflation pressure
means the maximum co ld inf lation pressure
to which a tire may be inflated . Also called
"maximum inflation press ure."
Normal occupant weight
means 150 lbs . (68 kilograms) times the
number of occupants seated in the vehicle up
to the tota l seating capacity of your vehicle.
Occupant distribution
means distribution of occupants in a veh icle.
Outer diameter
means the overall diameter of an inflated new
tire .
Overall width
means the linear distance between the exteri­
ors of the sidewalls of an inflated tire, includ­
ing e levations due to labeling, decorations, or
protective bands or ribs. means a layer of
rubber-coated parallel cords.
Production options weight
means the combined weight of those installed
regular production opt ions we ighing over 5
lbs. (2.3 kg) in excess of those standa rd 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 spec ial trim.
Radial ply tire
means a pneumatic tire in which the ply cords
that extend to the beads are laid at substan­
tially 90 degrees to the centerline of the
tread.
Recommended inflation pressure
see ~ page 246, Cold tire inflation pressure .
Reinforced tire
means a tire design to operate at higher loads
and at higher inflation pressures than t he cor­
responding standard tire. Reinforced tires
may be identified as "XL", "xl", "EXTRA LOAD",
or "RF" on the sidewal l.
Rim
means a metal support for a tire or a t ire and
tube assembly upo n which the tire beads are
seated .
Rim diamete r
means nominal diameter of the bead seat. If
you change your wheel s ize, you wi ll have to
purchase new tires to match the new r im di­
ameter .
Rim size designation
means rim diameter and width.
Rim width
means nominal distance between rim flanges.
Sidewall
means that portion of a t ire between the
tread and bead .
•
•

.... N .... N
0 J:
"". .... I.O
"' ....
"' ....
Tires and wheels 249
Occupant loading and distribution for vehicle normal load for various designated seating
capacities Designated seating capacity, Vehicle normal load, number Occupant distribution in a nor-
number of occupants of occupants mally loaded vehicle
4 2 2
in front
5 3 2 in front, 1 in back seat
Cold tire inflation pressure
Tire pressure affects the overall handling, performance and safety of a vehicle.
Fig. 208 Tire pressure label: located on driver 's side B­
pillar
Tire pressure generally refers to the amo unt
of air in a tir e 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 interna ­
tional measuring unit and in pounds per
squa re inch (PSI). Tire pressure is based in
part on the vehicle's design and load limit -
the greatest amount of weight that the vehi­
cle can carry safely and the tir e size. The prop­
er tire pressure is frequent ly 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 p ressure 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 p res­
sure" recommendations. The tir es would then
be underinflated and could fail suddenly .
Maintaining proper tire pressure is one of the
most important things you can do to help
avoid sudde n tire failure . Underinflated tire s
are a major cause of sudden tire failure. Keep­
in g tires at the right pressure is also impor-
-"' --~ -- ,e
• (:::=~. ~: I =: I :,.. I)( ::: ) l3 n,........,..,.__...,~ ........ ....,_...... • ... _ .. , ....................................... ..,_ "" ..
-""u
--
-...........
- KPA. a PS I
- KPA.
a PSI
-KPA. a PSI
Fig. 209 Tire pressure label
tant for safe and respons ive ve hicle hand ling,
traction, braking and load carrying.
Tire pres­
sures are particularly important when the
vehicle is being driven at higher speeds, and
then especially when heavily loaded even
within the permissible load-carrying capaci­
ties 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.
The tire pressure label is located on the driv­
er's side B-pillar. The tire pressure labe l lists
the recommended cold tire inflat ion pressures
for the vehicle at its maximum capacity
weight and tires that were on your veh icle at
the time it was manufactured.
If you wish to improve comfort when operat­
ing the vehicle at normal load (up to 2*/3
occupants), you can adjust tire pressures to
those specified for normal vehicle load. Be­
fore operating the vehicle at maximum load,
you must increase the tire pressures to those specified for maximum vehicle load
¢ ,&. . IJi,,-

250 Tires and wheels
Bear in mind that the tire pressure monitoring
system* can only monitor the tire pressures
you have stored . The system does not recog­
nize the load condit ion of your vehicle.
The effectiveness of the tire pressure monitor ­
ing system* will be impaired if you store nor­
mal load pressures but then operate the vehi ­
cle at its max imum load
c:> &. .
See the illustration c:> fig. 208 for the location
of the label on driver's side B-pillar (color of
the act ua l label and exact location on the ve­
hicle will vary slightly). Note
that the following table is accurate at
the time of going to press and is subject to
change. In the event of d iscrepancies, the t ire
pressure label is located on the driver's side B­
pillar always takes precedence.
The table below lists the recommended cold
t ir e inflation pressures for the Audi mode l
covered by your Owner's Literature at the vehi­
cle's capacity weight and the t ire sizes instal­
led on the respective models as orig inal
equipment, or as a factory opt ion.
Tire pressure
Model/En- Tire designation normal load condition full load condition
gine fronta> reara>
front rear
PSI kPA
PSI kPA PSI kPA PSI kPA
A8/A8 L: 235/55 R18 104H
35 240 32 220 36 250 38 260
3.0 liter
255/45 R19 104H 35 240 32 220 36 250 38 260
6-cylinder
265/40 R20 104H 35 240 32 220 36 250 38 260
265/40 R20 104V 33 230 32 220 33 230 35 240
275/35 R21103Y XL 35 240 32 220 36 250 35 240
A8/A8 L: 235/55 R18 104H 35 240
32 220 38 260 38 260
4.0 liter
255/45 R19 104H 35 240 32 220 38 260 38 260
8-cylinder
265/40 R20 104H 35 240
32 220
38 260
38 260
265/40 R20 104V 33 230 32 220
35 240 35 240
275/35 R21103Y
XL 35 240
32 220
38 260
38 260
ASL
: 265/40 R20 104V 35 240 32 220 36 250 35 240
6.3 liter
255/45 R19 104H 36 250 32 220
39 270
38 260
12-cylin-
265/40 R20 104H 36 250 32 220 39 270 38 260
der
275/35 R21103Y XL
35 240 32 220 36 250
35 240
58: 265/40 R20 104V 36 250 32 220
39 270 38 260
4.0 liter
265/35 R21101 Y 39 270 35 240 44 300 42 290
8-cylinder
275/35 R21103Y XL 39 270
35 240
44
300 42
290
XL= reinforced or extra load tire. It may also appear as xl, EXTRA LOAD, or RF on the tire side-
wall.
al n orma l lo ad co ndi tio n~ page 249.
The correct tire pressure for the spare wheel is
locat ed on a label on the driver's side B-pillar.
Because technical changes may be made to
ve hicl e equipment during the model year, al­
ways compa re the tire size designation on the tire
pressu re lab el on your vehicle wi th the
tires on your vehicle. Make sure that the tire
s iz e inform ation on the vehicle label is the
same as the size of the tires on the vehicle.
This is espec ially important if the vehicle be-
l ongs to someone e lse or yo u bought the ..,.

256 Tires and wheels
Incorrect wheel alignment
Incorrect wheel alignment can cause exces­
sive tire wear, impairing the safety of the vehi­
cle. If tires show excessive wear, have the
wheel alignment checked by an authorized
Audi dealer or qualified workshop.
All Wheel Drive
Vehicles with quattro must always have tires
of the same size, construction and tread type.
For details see Qpage 202 .
.&_ WARNING
Sudden tire failure can lead to loss of con­
trol, a crash and serious personal injury!
- Never drive a vehicle when the tread on
any tire is worn down to the wear indica­
tors.
- 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 away 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 histo­
ry." Old used tires may have been dam­
aged even though the damage cannot be
seen that can lead to sudden tire failure
and loss of vehicle control.
New tires and replacing tires and wheels
New tires and wheels have to be broken in .
Fig. 212 Tir e specificat ion codes on the s idewall of a
t ire
No. Description
@ Nominal width of tire in millimeters
® Ratio of height to width (aspect ratio)
© Radial
® Rim diameter code
® Load index and speed rating
(J) U.S . DOT tire identification number
® Audi Original tire
® Sever snow conditions
@ Tire ply composition and materials
used
@ Maximum load rating
@ Treadwear, traction and temperature
grades
@ Maximum permissible inflation pres-
sure
The tires and rims are essential parts of the
vehicle's design . The tires and rims approved
by Audi are specially matched to the charac­
teristics of the vehicle and can make a major .,..