ECO mode AUDI S8 2014 Owner's Guide

164 Airbag system
Monitoring the
Advanced Airbag System
Cl! (USA models)/!f (Canada models)
Airbag monitoring indicator light
Two separate indicators monitor the function
of the Advanced Airbag System: the airbag
monitoring indicator light and the
PASSEN­
GER AIR BAG OFF
light.
The Advanced Airbag System (including the
electronic control unit, sensor circuits and sys­
tem wiring) is monitored continuously to
make sure that it is functioning properly
whenever the ignition is on. Each time you
switch on the ignition, the airbag monitoring
indicator light
I (USA mode ls)/ fll (Canada
models) will come on for a few seconds (self
d iagnost ics).
The system must be inspected when the
indicator light
I (USA models)/E,I
(Canada models):
-does not come on when the ignition is
switched on,
- does not go out a few seconds after you have switched on the ignition, or
- comes on while driving.
If an airbag system malfunct ion is dete cted,
the indicator light will first start flashing to
catch the driver's attention and then stay on
continuously to serve as a constant reminder
to have the system inspected immediately.
If a malfunction occurs that turns the front
airbag on the passenger side
off, the PASSEN­
GER AIR BAG OFF
light will come on and stay
on whenever the ignition is on.
A WARNING
An airbag system that is not functioning
properly cannot provide supplemental pro­
tection in a frontal crash.
- If the airbag indicator light
c::> page 18
comes when the vehicle is be ing used,
have the system inspected immediate ly
by your authorized Audi dealer. It is pos- sible
that the airbag will inflate when it
is not supposed to, or will not inflate
when it should.
PASSENGER AIR BAG OFF light
Fig. 168 Sect io n from the instrument pane l: PASSEN­
GER AIR BAG O FF lig ht
The PASSENGER AIR BAG OFF light is located
in the center of the instrument panel
c::>fig . 168 .
The PASSENGER AIR BAG OFF light will come
on and stay on to tell you when the front Ad­
vanced Airbag on the passenger s ide has been
turned
off by the electron ic control unit. Each
t ime you switch on the ign it ion, the
PASSEN­
GER AIR BAG OFF
light will flash for a few
seconds and:
- will stay on if the front passenger seat is not
occupied,
- will stay on if there is a small ch ild or child
restraint on the front passenger seat,
- w ill go out if the front passenger seat is oc ­
cupied by an adult as registered by the
weight-sensing mat.
The
PASSENGER AIR BAG OFF light must
come on and stay on
if the ignition is on and
- a car bed has been installed on the front seat, or
- a rearward-facing child restraint has been
installed on the front passenger seat, or
- a forward-facing child restraint has been in-
stalled on the front passenger seat, or
liJI,

removing, servicing or rep airing a part in an
area of the vehicle can damage a part of an
airbag system and prevent that system from
working properly in a co llision.
There are some important things you have to
know to make sure that the effectiveness of
the system will not be impa ired and that dis­
carded components do not cause injury or pol ­
lute the environment.
A WARNING
Improper care, servicing and repair proce­
dures can increase the risk of personal in­
jury and death by preventing an airbag from deploy ing when needed o r deploying
an airbag unexpectedly:
- Never cover, obstruct, or change the
steering wheel horn pad or airbag cover
or the instr ument pane l or modify them
in any way.
- Never attach any objects such as cup
holders or telephone mountings to the
surfaces covering the airbag units.
- For cleaning the horn pad or instrument
pane l, use only a soft, dry cloth or one
moistened with plain water. Solvents or
cleaners cou ld damage the airbag cover
or change the stiffness or strength of the
material so that the airbag cannot de­
ploy and protect properly.
- Never repa ir, adjust, or change any parts
of the airbag system.
- All work on the steering wheel, instru­
ment panel, front seats or electrical sys­
tem (including the installation of audio
equipment, cellular telephones and CB
radios, etc.) must be performed by a
qualified technician who has the training
and special equipment necessa ry.
- For any work on the airbag system, we
strongly recommend that you see your
authorized Aud i dealer or qualified wo rk­
shop.
- Never mod ify the front bumper or parts
of the veh icle body.
- Always make sure that the side airbag
can inflate witho ut interference:
Airbag system 167
-Never install seat covers or replace­
ment upholstery over the front seat­
backs that have not been specifically
approved by Audi.
- Never use additional seat cushions that
cover the areas where the side airbags i nflate.
- Damage to the original seat covers or
to the seam in the area of the side a ir­
bag module must always be repaired
i mmediately by an author ized Audi
dealer.
- The airbag system can be activated only
once. After an airbag has inflated, it must be replaced by an authorized Aud i
dea ler or qualified technician who has
the technical information, training and
specia l equipment necessary .
- The airbag sys tem can be deployed only
once. After an airbag has been deployed,
it must be replaced with new replace­
ment parts designed and approved espe­
cially for your Audi model version. Re­
placement of complete airbag systems
or airbag components must be per­
formed by qualified workshops only. Make sure that any airbag serv ice action
is entered in your Audi Warranty
& Main­
tenance booklet under
AIRBAG REPLACE­
MENT RECORD.
- For safety reasons in severe accidents,
the alte rnator and starter a re separated
from the vehicle battery with a pyrotech­
nic circuit interrupter.
- Work on the pyrotechnic c ircuit inter­
rupter must only be performed by a
qualified dea ler - risk of an accident!
- If the vehicle or the circuit interrupter
i s scrapped, all applicable safety pre­
cautions must be followed.
@) For the sake of the environment
Undeployed airbag modules and preten­
sioners might be classif ied as Perchlorate
Material - special handling may apply, see
www .dtsc .ca. gov/hazard o u sw a ste/ per­
ch lorate. When the veh icle or parts of the
restraint system including airbag modules ..,.
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seat. The weight of a child restraint and its
"footprint" vary for different kinds of child re­
straints and for the different models of the
same kind of child restraint offered by child restra int manufacturers.
The weight ranges for the individual types, makes and mode ls of ch ild restra ints that the
NHTSA has specified in the Safety Standard
together with the we ight ranges of typical in­
fants and typical 1 year -old child have been
stored in the control unit of the Advanced A ir­
bag System . When a chi ld restraint is being
used on the front passenge r seat with a typi­
cal 1 year -old ch ild, the A dvanced Airbag Sys­
tem compares the we ight measured by the
weight sensing mat with the information stor­
ed in the electronic control unit.
The electron ic contro l unit al so registers the
tension on the front passenger safety be lt.
The tension on the safety be lt for the front
passenger seat will be different for an adult
who is properly using the safety belt as com­
pared to the tension on the be lt when it is
used to attach a child restraint to the seat.
T he sensor below the latch for the safety belt
for the front seat passenger measures the
tension on the belt . T he input from this sen­
sor is t hen used w ith the we ight to "decide",
whether there is a ch ild restraint with a typ ica l
1 year-o ld child on the front passenger seat
and whether or not the airbag must be turned
off .
Child restraints and Advanced Airbags
Regard less of the child restraint that you use,
make sure that it has been certified to meet
United States Federal Motor Vehicle Safety
Standards and has been certified by its manu­
facturer for use with an airbag . Always be sure
that the chi ld restraint is p roperly instal led at
one of the rear seat ing pos itions . If in excep­
tional ci rcumstances you must use it on the
front passenger seat, carefu lly read all of the
information on child safety and Advanced Air­
bags and heed a ll of the app licable WARN­
INGS. Make certain that the child restraint is
correctly recognized by the weight-sensing
Child Sa fet y 1 79
mat inside the front passenger seat, that the
front passenger airbag is turned off and that
the a irbag status is always correct ly signaled
by the
PAS SENGE R AIR BAG OFF light.
Many types and models of child restraints
have been available over t he years, new mod­
els are introduced regu larly incorporating new
and improved des igns and o lder models are
taken out of product ion. Ch ild restraints are
not standard ized . Child restraints of the same
type typ ically have d ifferent weights and sizes
and different 'footpr ints,' the size and shape
of the bottom of the ch ild restrai nt that sits
o n the seat, when they a re insta lled on a veh i­
cle seat. These diffe rences make it v irtually
impossible to certify compliance with the re­
quirements for advanced airbags with each
and every ch ild restraint that has ever been
sold in the past or will be sold over the course
of the useful life of your veh icle.
For this reason, the United States National
Highway Traffic Safety Adm inistrat ion has
published a list of spec ific type, makes and
models of child restraints that must be used
to certify comp liance of the Advanced Airbag
System in your veh icle with the suppression
requirements of Federal Motor Vehicle Safety
Standa rd 208. These chi ld restraints are :
Subpart A - Car bed child restraints
Model Manufactured on or
after
Angel Guard Angel September 25, 2007 R ide AA 2403FOF
Subpart B - Rear-facing child restraints
Model Manufactured on or
after
Century Smart Fit December 1, 1999
4543
Cosco Arriva September 25, 2007 22-013PAW and base
22-999WHO
E venflo Discovery Ad- December 1, 1999
just Right 212
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210 Driving and environment
The consumption estimates as published
by ENVIRONMENTAL PROTECTION AGENCY
(EPA) and Transport Canada may not corre­
spond to your actual consumption on the
road, which will vary depending upon vehi ­
cle load and speed, road and weather con­
ditions, trip length, etc.
Drive smoothly and keep a lookout
ahead
Vehicles use the most fuel when they are ac­
celerating.
• Avoid unnecessary accelerating and braking.
Vehicles use the mo st fuel when they are ac­
celerating. If you anticipate what is going to happen next, you will need to brake less and,
thus , accelerate less. Let the vehicle coast
whenever possible -for example when you see
that the next traffic light is red.
Avoid full throttle
Driving at moderate speeds saves fuel and
improves your mileage.
• Try and keep well below your car's maximum
speed .
Accelerating gently reduces fuel consump­
tion, engine wear, and does not disturb the
environment .
Fuel consumption, exhaust emissions and en­
gine noise increase disproportionately at high
speeds. If you drive at approximately three
quarters of top speed, fuel consumption will
be reduced by one half. Never drive faster
than the posted speed limit and weather con­
ditions permit.
Reducing unnecessary idling
Even when your car is just idling it burns up
fuel.
• Shut the engine off when you are not driving
the vehicle. •
Do not warm up the vehicle by letting the
engine run at idle.
The idling phase is automatically reduced for
vehicles with the Start/Stop system. It is effi­
cient to switch off the engine in vehicles with­
out the Start-Stop-System when stopped at
railroad crossings and long red lights. Turning
the engine off for jus t 30-40 seconds saves
more fuel than is burned by starting the en-
. . gme again.
It takes a long time for the engine to warm up
fully when it is running at idle. However, wear
and noxious emissions are especially high
when the engine is warming up . So you should
drive away as soon as you start the engine and
avoid running at high rpms while the engine is
still warming up.
W Note
Do not leave engine idling unattended af­
ter starting . If warning lights should come
on to indicate improper operation, they
would go unheeded. Extended idling also
produces heat, which could result in over­
heating or other damage to the vehicle or
other property.
Regular maintenance
A badly tuned engine unnecessarily wastes a lot of fuel.
• Have your vehicle serviced at regular inter-
vals.
By having your vehicle regularly serviced by an
Audi dealer helps to ensure that it runs prop­
erly and economically. The condition of your
vehicle not only affects its safety and ability to
hold its value, it also affects
fuel consump­
tion.
Check your oil each time you
fill your tank.
The amount of oil used is related to engine
load and speed.
It is normal for the oil consumption of a new
engine to reach its lowest value after a certain
mileage has been driven . ..,.

212 Trailertowing
Trailer towing Driving with a trailer
General information
Your Audi was designed primarily for passen­
ger transportation .
If you plan to tow a trai ler, please remember
that the additional load will affect durability,
economy and performance .
Trailer towing not only places more stress on the vehicle, it also calls for more concentra­
tion from the driver.
For this reason, always follow the operating
and driving instructions provided and use
common sense.
(D Note
If you are going to tow a trai ler, you must
activate the trailer operation mode
i::> page 212, Operating instructions .
Technical requirements
Trailer hitch
Use a weight-carrying hitch conforming to the
gross trailer weight. The hitch must be suita­ ble for your vehicle and trailer and must be
mounted securely on the veh icle 's chassis at a
technically sound location . Use only a trailer
hitch with a removable ball mount. A lways
check with the trai le r hitch manufacturer to
make sure that you are using the cor rect
hitch.
Do not use a bumper hitch.
The hitch must be installed in such a way that
it does not interfere with the impact-absorb­
ing bumper system. No modifications should
be made to the vehicle exhaust and brake sys­
tems. From time to time, check that all hitch
mounting bo lts remain securely fastened.
When you are not towing a trailer, remove the
trailer hitch ball mount. This prevents the
h itch from causing damage should your veh i­
cle be struck from behind~ &.
Trailer brakes
If your trailer is equipped with a brak ing sys­
tem, check to be sure that it conforms to all
regulations.
T he trailer hydraulic brake system must not be
direc tly connected to the vehicle's hydraulic
brake system .
Safety chains
Always use safety chains between your veh icle
and the tra iler.
Trailer lights
Trailer lights must meet all regulations. Be
sure to check with your Audi dealer for correct
wiring, switches and relays.
Mirrors
If you are unable to see the traffic behind you
using the regular outside mirrors, then you
must install extended mirrors. It is important
that you
always have clear v is ion to the rear .
A WARNING ,~ -
After removing the trailer hitch, do not
store it in your vehicl e. In case of sudden
braking, the hitch could fly forward and in­
jure you or your passengers.
Operating instructions
Fig. 189 MMI display : tow ing mode on
Maximum traile r weight
A trai ler for your vehicle is limited to a typical
class 1 or class 2 trailer. .,.

@ For the sake of the environment
-Before changing your oil, first make sure
you know where you can properly dispose
of the used o il.
- Always dispose of used engine oil proper­
l y. Do not dump it on garden soi l, wood­
ed areas, into open streams or down
sewage dra ins.
- Recycle used engine oil by taking it to a
used engine oil collection facility in your
area, or contact a service station .
Engine cooling system
Coolant
The engine coolant performs two functions: it
keeps the engine from overheating and it pro­ tects the engine from freezing in the winter.
The cooling system is sea led and generally re­
q uir es lit tle atten tion .
The cooling system has been filled at the fac ­
tory with a pe rmanent coo lant which does not
need to be c hanged. The coolant consists of a
mixture o f spec ial ly conditioned water and the
manuf acturer 's glyco l-based cool ant ad di-
tiv e G13 antifreeze with ant icorros ion addi ­
tives (50% for USA models ; 60% for Canadian
mod els) . This mixture both assures the neces­
sary frost protection and p rotect s metal com ­
ponents in the engine's coo ling system from
corrosion and scaling . It a lso raises the boil­
i ng point of the coolant .
Do not reduce the concentration o f the coo l­
ant in the summer by adding plain water.
The
proportion of coolant add it ive must be at
l e a st 50 % but not mor e than 60 %
to main­
tain antifreeze protection and coo ling efficien­
cy .
If the coolant frost protect io n is too low,
the coolant cou ld free ze and dam age the veh i­
cle heating and eng ine cooling system.
For yea r-round driving, antifreeze is added at
the fac to ry for tempera tures down to:
-- 31°F( -35°C)USA
- -40 °F ( -40 °C) Canada.
Checkin g and fillin g 239
If you must add coo lant, use a mixture of wa ­
ter and coolant additive . Mix ing the coo lant
additive with distilled water is recommended.
_& WARNING
Before you c heck anything in the engine
compartment, always read and heed a ll
WARNINGS
c> .& in Working in the engine
comportment on page 231.
Q) Note
- Before winter sets in, have the coo lant
checked to see if the coolant additive in
your vehicle is sufficient to meet the cli­ mate condi tions. This is especi ally impor­
tan t if you live i n a region wher e th e win­
ter is ex treme ly co ld. If necessary, i n­
crease t he p ropo rtion of coo lant add itive
to 60% .
- Whe n ad ding coolant additive t o yo ur
c ooling sys tem, reme mbe r:
- We recommend using on ly coolant ad­
d itive G12++ or Gl3 for your vehicle .
This coolant additive is availab le at au­
thor ized Audi dealers . O ther types of
a ntifreeze can s ignifica ntly reduc e cor­
rosion prote ction. The result ing cor ro­
sion can cau se a loss o f coolan t and se­
rio us engine d amage .
- Do not add any ty pe of rad iator leak seal­
a nt to yo ur vehicle 's engine c oolant .
A dd ing radia tor repair fl uid may adverse ­
ly affect the f unction and pe rformance of
your cooling system and co uld resu lt in
damage not covered by your New Ve hicle
L imited Warranty.
-
•
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242 Checking and filling
-The auxiliary e lectric fan is temperature
controlled and can switch on suddenly
even when the engine is not runn ing.
- The auxiliary radiator fan switches on au­
tomatically when the engine coolant
reaches a certain temperature and will
continue to run until the coolant temper­
ature drops .
Brake fluid
Checking brake fluid level
The brake fluid level can be checked with a
quick glance.
Fig . 205 E ng ine co mpartment: cove r on the brake fluid
r eservo ir
Before you check anything in the engine com­
partment,
always read and heed all WARN­
INGS 9 &_ in Working in the engine compart­
m ent on page 231.
.. Read the brake fluid level from the brake
fluid reservoir
9 fig . 205, q page 233. The
brake fluid leve l must be between the "MIN"
and "MAX" markings.
The location of the brake fl uid reservoir can be
seen in the engine compartment illustrat ion
9 page233.
The fluid level may drop slightly after some
time due to the automatic adjustment of the
brake pads. This is not cause for alarm.
If the brake fluid level falls
considerably be­
low the "MIN" mark, the brake warning/ind i­
cator light
1111 (U.S. models)/ . (Canadian
models) will come on
q page 14. Do not con­
tinue to operate the vehicle . T he complete
brake system should be thoroughly checked by an authorized Audi dealer or other quali­
fied fac ility and the cause corrected.
If th e
brake flu id level is too low, the brake wa rning/
indicator light will illuminate. Contact an au­
thorized Audi dealer
immediately.
Changing brake fluid
Have the brake fluid changed by on experi­
enced technician.
Brake fluid absorbs moisture from the air. If
the water content in the brake fluid is too
high, corrosion in the brake system may result
a fter a period of time. The boiling point of the
brake fluid will also decrease considerably and
decrease braking performance .
Therefore, the brake fluid must be changed
every two years. Always use new brake flu id
which conforms to Federal Motor Veh icle
Standard "FMVSS 116 DOT 4" .
The brake fluid reservoir can be difficu lt to
reach, therefore, we recommend that you
have the brake fluid changed by your author ­
ized
Audi dealer . Your dealer has the correct
tools, the right brake fluid and the know-how
to do this for you .
.&, WARNING
-Brake fluid is poisonous. It must be stor­
ed only in the closed origina l container
out of the reach of children!
- Brake failure can result from old or inap­
propriate brake fluid. Observe these pre­
cautions:
- Use only brake fluid that meets SAE
spec ification
J 1703 and conforms to
Federa l Motor Vehicle Standard 116.
Always check with your authorized Aud i
dealer to make sure you are using the
correct brake fluid. The correct type of
brake fluid is also indicated on the
brake fluid reservoir .
- The brake fluid must be new. Heavy use
of the brakes can cause a vapor lock if
the brake fluid is Left in the system too
lllJ.

Tires an d wheel s 253
Bear in mind that the ti re press ure monitoring
system* can only monitor the tire pressures
you have stored. The system does not recog ­
n ize 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 maximum load
c;, &.
See the i llustration c;, fig. 208 for the location
of the label on driver's side B-pillar (co lor of
the actua l labe l and exact location on the ve­
h icle wi ll 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 tire
pressure label is located on the driver's side B­
pillar always takes precedence.
The table below lists the recommended cold
tire inflat ion 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 option.
Tire pressure
Model /En-
Tire design ation normal load condition
full load condition
gine fronta> reara>
front rear
PSI kPA PSI kPA PSI kPA PSI kPA
AB /AB L: 235/55 R18 104H
35 240 32 220 36 250 38 260
3 .0 lit er
255/45 R1 9 104H 35 240
32 220 36 250 38 260
6-cy lind er
26 5/40 R2 0 104H 35 240 32 220 36 250 38 260
265 /40 R20 104 V 33 230 32 220 33 230 35 240
275
/35 R 2110 3Y XL 35 240 32 220 36 250 35 240
A8/A8 L: 235 /55 R1 8 104H 35 240
32 220 38 260 38 260
4.0 l it e r
255/4 5 R19 104H 35 240 32 220 38 260 38 260
a-cy lind er
26 5/ 40 R 20 104H 35 240
32 220
38 260
38 260
2
6 5/40 R 20 104V 33 230 32 220 35 240 35 240
27
5/35 R2 110 3Y XL 35 240 32
220
38 260
38 260
AB L
: 265/40 R20 104 V 35 240 32 220 36 250 35 240
6.3 liter
255 /45 R1 9 104H 36 250 32 220
39 270
38 260
12
-cy lin-
26 5/40 R 20 104H 36 250 32 220 39 270 38 260
der
275/35 R 21 103 YXL
35 240 32 220 36 250
35 240
58
: 2 65/40 R 20 10 4V 36 250 32 220 39 270 38 260
4.0 liter
265 /35 R21101 Y 39 270 35 240 44 300 42 290
a-cy lind er
275/35 R 2110 3Y XL 39 270 35 240
44
300 42
290
XL= reinf orce d or extra lo ad tir e. It ma y als o appe ar a s x l, E XTRA LOAD, or RF on th e tire s ide-
w all .
al no rmal load co ndit ion c:> page 252.
The correct tire pressure for the spare wheel is
l ocated on a label on the dr iver's side B-pilla r.
Because technical changes may be made to
ve hicle equ ipment dur ing the model yea r, a l­
ways compa re the tire size designation on the tire pressu
re label on you r vehicle with the
t ires on you r vehicle. Make sure that the t ire
size in formation on the vehicle labe l is the
same as the size of the tires on the vehicle.
This is especially important if the vehicle be-
l ongs to someone else or yo u bought the ...,
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chains because the vehicle will be ex­
tremely low. If you do drive with snow
chains on while the vehicle is at this lev­
el, the snow chains might severe ly dam­
age the wheelhouse and other parts of
the veh icle .
@ Tips
Where snow cha ins are mandatory oncer­
tain roads, this normally also applies to
veh icles with All Wheel Drive.
Wheel bolts
Wheel bolts mu st always be tigh tened to the
correc t torque .
The design of whee l bolts is matched to the
factory in sta lled r ims. If different rims are fit ­
ted, the correct wheel bolts with the right
length and correctly shaped bolt heads must
be used . This ensures that wheels are f itted
secure ly and that the brake system f unctions
correctly .
In certain circumstances, you may not use
wheel bolts from a d iffe rent vehicle -even if it
i s the same mode l
¢page 294.
A WARNING
Imprope rly tig hte ned or maintained whee l
bolts can be come loose causin g loss of
contro l, a co llision and serious persona l in­
jury .
- Alw ays keep the w heel bolts and the
th reads in the wheel hubs clea n so the
wheel bolts can turn easily and be prop­
er ly tightened .
- Never grease or oil the wheel bo lts and
the threads in the w heel h ubs. They can
become loose while driving if greased or
o iled, even if tightened to the specif ied
torque.
- Only use wheel bolts that belong to the rim being installed.
- Never use different whee ls bolts on your
vehicle .
- Always maintain the co rrect tightening
torq ue for the wheel bo lts to reduce the
Tire s an d wheel s 265
risk of a wheel loss. If the tighte ning tor­
que of t he wheel bolts is too low, they
can loosen and come out when the vehi­
cle is mov ing . If the tighte ning torque is
too h igh, the wheel bol ts and threads
can be damaged and the whee l can be­
come loose.
(I) Note
The specified torque for the whee l bolts is
90 ft lb ( 120 Nm) with a tole ranc e of± 7,4
ft lb(± 10 Nm). Torq ue whee l bolts diago­
nally. Afte r cha nging a whee l, the torq ue
must be checked as soon as possible wi th a
torque w rench -prefe rably by an au thor­
i z ed Audi dealer or qualif ied workshop .
Low aspect ratio tires
Your Audi is facto ry-eq uipped with low aspect
ratio tires. These tires have been thoro ughly
tested and been se lected specifically for your
model for their superb performance , road fee l
and handling under a variety of driving cond i­
tions . Ask your authorized Audi dealer for
more details.
The low aspect ratio of these t ires is ind icated
by a numeral of
55 or less in the tire's size
designation . The numera l rep resents the ratio
of the t ire's sidewall height in relation to its
t read width ex pressed in perce ntage. Conven ­
tion al tires have a he igh t/w idth ratio of 60 or
more.
The performance of low-aspe ct-ratio tire s is
particularly sensitiv e to improper infla tion
pres sure. It is therefore important that l ow
a spect ratio tires are inflated to the specified
pre ssure and that the inflation pressure is
regularly checked and maintained. Tire pres·
sures should be checked at least once a
month and always before a long trip
¢ page 254 , Checking tire pressure .
What you can do to avoid tire and rim
damage
Low aspect ratio tires can be damaged more
easily by impact w it h potholes , curbs, gul lies ..,.
•
•

-Always store the vehicle tool ki t, the jack
and t he replaced t ire in the luggage com­
partment ¢
page 141 .
@ Tips
Before chang ing the wheel, you must acti­
vate the jacking mode, so that the auto­
mat ic controls for the Adaptive Air Sus­
pens ion do not make it more difficu lt to
lift the vehicle with the jack¢
page 2 75.
Changing a wheel
When you change a wheel, follow these­
quence described below step-by-step and in
exactly that order .
1. Activate the vehicle jack mode
c:;.page275.
2. Remove the decorative whe el co ver* . For
mo re deta ils see also
c:;, page 2 73, Deco­
rative wheel covers
or c:;, page 2 7 4,
Wheels with wheel bolt caps.
3 . Loosen the wheel bo lts c:;, page 2 7 4.
4. Locate the proper mo unt ing po int for the
jack and align the jack below that point
c:;, page 2 75.
5 . Rai se the car w ith the jack c:;, page 275.
6. Remove the wheel with the flat tire and
then install
the spare c:;, page 2 76 .
7. Tighten all wheel bo lts light ly .
8 .
Lower the ve hicle w it h the jack.
9 . Use t he wheel bolt wre nch and
firmly
tighte n all whee l bolts c:;. page 274.
10. Rep lace the de corative wheel cover* .
11. D eactivate the vehicle jack mode in t he
MMI:
! CARI fu nction button > Car system s
control button > Servicing & che cks > Air
susp.: jack mode > Off .
The vehicle jack mode sw itches off automati ­
cally at speeds above 10 km/h.
A WARNING
Always read and follow all WARNINGS and
information
c:;, .&. in Raising the vehicle on
page 275
and c:;, page 277.
What do I d o now ? 273
After changing a wheel
A wheel change is not complete without the
doing the following.
.,. Always store the vehicle tool kit, the jack*
and the replaced tire in the luggage com­
partment
c:;, page 141 .
.,. Check the tire pressure on the spare whee l
immed iate ly afte r mounting i t.
.,. As soon as poss ib le, have the
tight ening
torque s
on all wheel bolts checked w ith a
torque wrenc h. The co rrec t tighten ing tor­
que is 90 ft lb (120 Nm).
.,. Have the flat tire
replaced as soon as possi­
ble .
@ Tips
-If you notice that the wheel bo lts a re
corroded and difficult to turn while
chang ing a tire, they should be replaced
before you c heck the tightening torque.
- Drive at reduced speed until you have the tightening torques checked .
- After changing a whee l, the ti re press ure
in all four tires must be checked/correct­
ed and the tire press ure monitoring ind i­
cator must be sto red in the M MI
c:;. page268 .
Decorative wheel covers
Applies to veh icles: w ith decorative w hee l cove rs
The decorative wheel covers mus t be removed
first to access the wheel bolts.
Fi g. 22 1 Chang ing a whee l: Re moving th e w hee l cover
Removing
.,. Insert the hook (provided with the vehicle
t oo l kit) in the ho le in the whee l hub cover .
i,,.