2015 AUDI S4 wheel size

166 Child Safety
-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 rearward-facing child safety
seat in a rear seating position and have
the airbag system inspected immediately
by your authorized 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
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 size. 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
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 .,.

186 Intelligent technology
distance detected to the vehicle ahead is too
smal l.
Anti-slip regulation (ASR )
ASR reduces eng ine power when the drive
wheels begin to spin and adapts the fo rce to
the road condit ions. This makes it eas ier to
start, accelerate and drive up hills .
Electronic differential lock (EDL)
The EDL brakes wheels that are spinn ing and
transfers the d rive powe r to the other drive
wheel or whee ls if the vehicle is equipped with
a ll-wheel drive* . This function is not avai lab le
at higher speeds.
I n extreme cases , EDL automat ica lly switches
off to help keep the brake on the braked whee l
from ove rheating . EDL wi ll switch on again au­
tomatically when conditions have returned to
normal.
Steering recommendation
The ESC helps to stabilize the ve hicle by
changing the steering torque.
In vehicles with dynam ic steeri ng*, ESC also
he lps to stabilize the stee ring in critical s itua­
tions.
Electronic interaxle differential lock* /
selective wheel torque control*
The electronic interaxle d ifferential lock (front
wheel drive) or the select ive wheel torque
con trol ( all wheel d rive) oper ates when driving
through curves . The front whee l on the inside
of the cu rve or both whee ls on the inside of
the curve are b raked se lectively as needed.
This a llows more prec ise driving in c urves. The
applicable system may not activate when driv­ ing i n wet or snowy conditions.
A WARNING
- The ESC and its integrated systems can­
not overcome the laws of physics. This is
especially important on slippery o r wet
roads . If the systems begin acting to sta·
b iliz e your veh icle, you s hou ld immed i­
a tely c ha n ge your speed to match the
road and traffic cond itions. Do not let
the increased safety provided by these
systems tempt you to take risks. Do ing
so will increase the risk of a loss of vehi­
cle control, collision and serious personal
inj uries.
-Always adapt your speed to road, traffic and weather conditions. The risk of los­
ing control of the vehicle increases when
d riving too fast, espec ially through
curves and on slippe ry or wet roads, and
when dr iv ing too close to vehicles up
ahead. The ESC a nd its integrated sys­
tems canno t always p reven t collisions -
there is still a risk of acc idents!
- Always accelera te wi th spe cial care on
even, smooth s urfaces such as those that
are wet or covered with ice and snow.
The drive wheels can spin even with these assistance systems that cannot al­
ways he lp to red uce the risk of loss of ve­
h icle control.
(D Tips
- ABS and ASR only work cor rectly when
all four wheels are equipped with identi­
cal tires. D ifferent tire sizes can lead to a
reduction in engine power .
- Yo u may hear noises when the systems
descr ibed are working.
- If the ind icator light
DJ or ml (USA
mode ls)l iiJ (Canada models) appears,
there may be a malfunction<=>
page 18,
<=>page 19 .

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The all-wheel drive concept is designed fo r
high engine power. Your vehicle is exception ­
ally powerful and has exce llent dr iving charac­
ter istics both under normal driving conditions
and on snow and ice . Always read and follow
safety precautions
c> & .
Winte r tir es
When driving in the winter, your ve hicle with
all-wheel drive has an advantage, even with
regular t ires. In winter road conditions it may
be adv isable to mount winter tires (or all-sea­
son t ires) for imp roved driveability and brak­
ing: these tires must be mounted on
a ll four
w heel s.
See also c> page 254, Winter tires.
Tire chain s
Where tire cha ins are mandatory on certain
roads, th is normally also applies to vehicles
with all-wheel drive
c> page 255, Snow
chains.
R eplacing wheel s/tire s
Vehicles with all-wheel drive must a lways
have tires of the same size. Also avoid t ires
with d ifferent tread depths . For details see
page ~
page 248, New tires and replacing
tires and wheels.
Off-Ro ad dri ving ?
Your Audi does not have enough ground clear­
ance to be used as an off-road veh icle. It is
therefore best to avoid rough tracks and un­
even terrain as much as possible . Also refer to
c> page 193.
A WARNING
Always adjust your driving to road and traf­
fic condit ions . Do not let the ext ra safety
afforded by all-wheel drive tempt you into
taking extra risks .
- Although the all-whee l dr ive is very ef­
fective, a lways remember that b raking
capacity is limited by tire traction. Yo u
sho uld 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
Int ellig ent technolog y 191
could begin to slide on top of the water
(aquaplaning). If th is should occur, you
will have no warning from a sudden in­ crease in engine speed as w ith a front­
wheel drive veh icle . Always drive at
speeds which are su ited 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 energy 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 insuffic ient energy
available to start the eng ine .
Intelligent energy management in your vehi­
cle handles the distribution of e lectr ica l ener­
gy. Start ing 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 ene rgy management .
Batte ry diagnos is
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 ign ition switched off, it controls the
energy supply to the various electrical compo­
nents. Data from battery diagnos is is cons id­
ered .
Depend ing on the battery's state of charge,
individual consumers are gradually turned
off .,_ •
•

232 Tires a nd whee ls
Recommended inflation
pressure
see c:::> page 230, Cold tire infla­
tion pressure.
Reinforced tire
means a tire design to operate
at higher loads and at higher
inflation pressures than the
corresponding standard t ire .
Reinforced tires may be identi ­
fied as "XL", "xl", "EXTRA
LOAD", or "RF" on the sidewa ll.
Rim
means a meta l 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 yo u change your
wheel size, you will have to pur­
chase new t ires to ma tch the
new rim d iameter .
Rim size designation
means rim diameter and width.
Rim width
means nom inal distance be­
tween rim flanges.
Sidewall
means that por tion of a tire be­
tween the tread and bead.
Speed rating (letter code)
means the speed at wh ich a tire
is designed to be driven for ex­
tended periods of time . The rat­
ings range from 93 mph
( 1 50 km/h) to 186 mph
( 2 98 km/h)
c:::> page 2 50. You
may not find th is informat ion
on all tires because it is not re­
quired by law.
The speed rati ng letter code,
where applicable, is molded on
the ti re sidewall and ind icates
the maximum permissible road
speeds
c:::> & in Winter tires on
page 255.
Tire pressure monitoring
system*
means a system that detects
when one or more of a vehicle's
tires are underinflate d an d ill u­
minates a low tire press ure
warn ing telltale.
Tread
means that por tion o f a tire
that comes into contact with
the road.

Tires and wheels 235
Tire pressure generally refers to tant things you can do to help •
the amount of air in a tire that avoid sudden tire failure. Un-• '
it needs it to do its job and derinflated tires are a major
safely carry the combined load cause of sudden tire failure. of the entire vehicle and its con- Keeping tires at the right pres-
tents. Tire pressure is measured sure is also important for safe
in kilopascals (kPa), the inter- and responsive vehicle han-
national measuring unit and in dling, traction, braking and
pounds per square inch (PSI) . load carrying.
Tire pressures
Tire pressure is based in part on are particularly important
the vehicle's design and load when the vehicle is being driv-
limit - the greatest amount of en at higher speeds, and then
weight that the vehicle can car -especially when heavily loaded
ry safely and the tire size. The even within the permissible
proper tire pressure is frequent-load-carrying capacities ap-
ly referred to as the "recom-proved for your vehicle.
mended cold tire inflation pres-The recommended tire pres-
sure ." Air in the tires expands
sures for your Audi depend on
when the tire heats up because the kind of tires on your vehicle
of internal friction when it flex- and the number of passengers
es in use. The tire pressure is and/or amount of luggage you
higher when the tire has will be transporting.
warmed up than when it is The tire pressure label is locat-
"cold. " It is the inflation pres-
ed on the driver's side B-pillar.
sure in a "cold" tire that counts.
Therefore, you should never let The tire pressure label lists the
recommended cold tire infla-
air out of a warm tire to match
"cold tire inflation pressure" tion pressures for the vehicle at
its maximum capacity weight
recommendations. The tires
would then be underinflated and tires that were on your ve
-
and could fail suddenly. hicle at the time it was manu-
'"" factured
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sure is one of the most impor-1.1'1 ,...., 1.1'1 ,....,

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Tires and wheels 237
Model Tire designation Tire pressure
• Engine
normal load condition full load condition
• (up to 3 occupants)
front rear front rear
PSI kPA PSI kPA PSI kPA
PSI kPA
A4 Sedan: 225/55 Rl6 95H
32 220 29 200 33 230 35 240 2.0 liter All Season
4-cylinder 245/45 Rl 7 95H
All Season
32 220 29 200 33 230 35 240
245/40 Rl8 93V 32 220 29 200 33 230
35 240 High Performance
225/50 Rl 7 94H
33 230 30 210 35 240
36 250 All Season
245/40 Rl8 93H
33 230 32 220 36 250 38 260 All Season
255/35 Rl9 96V XL
32 220
30 210
35 240
35 240
High Performance
allroad: 225/55 Rl 7 97H
30 210 30 210 33 230 36 250 2.0 liter All Season
4-cylinder 245/45 Rl8 lOOH
All Season
32 220 32 220 33 230 36 250
24S/4S R18 96Y
30 210 30 210 33 230 36 250 High Performance
245/40 R19 98Y XL
32 220 29 200 35 240 38 260 High Performance
S4 Sedan: 245/40 Rl8 93H
36 250 32 220 41 280 41 280 3.0 liter
All Season
6-cylinder 245/40 Rl8 93Y
High Performance
39 270
35 240 41
280 41
280
255/35 Rl9 96YXL
39 270 33 230 41 280 41 280 High Performance
XL= reinforced or extra load tire. It may also appear as xl, EXTRA LOAD, or RF on the tire side-
wall.
The correct tire pressure for the
spare wheel is located on a la­
bel on the driver's side B-pillar.
Because technical changes may
be made to vehicle equipment
during the model year, always
compare the tire size designa- tion on the tire pressure label
on your vehicle with the tires on
your vehicle. Make sure that the
tire size information on the ve­ hicle label is the same as the
size of the tires on the vehicle.
This is especially important if
the vehicle belongs to someone ""

Incorrect wheel alignment
Incorrect wheel alignment can
cause excessive tire wear, im­
pairing 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 al­
ways have tires of the same size, construction and tread
type. For details see
¢ page 190 .
A WARNING
Sudden tire failure can lead
to loss of control, 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 haz­ ard, 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 and wheels 24 7
-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 damaged even though
the damage cannot be seen
that can lead to sudden tire
failure and loss of vehicle
control.
•
•
'

252 Tires and wheels
Maximum Permissible
Inflation Pressure
This number is the greatest
amount of air pressure that
should ever be put in the tire
under normal driving condi­
tions.
.&_ WARNING
-Using incorrect or unmatch­ ed tires and/ or wheels or improper tire and wheel
combinations can lead to loss of control, collision and
serious personal injury.
-Always use tires, rims and wheel bolts that meet the
specifications of original
factory-installed tires or
other combinations that have been specifically ap­
proved by the vehicle manu­
facturer.
-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 damaged even though
the damage cannot be seen
that can lead to sudden tire
failure and loss of vehicle
control.
-All four wheels must be fit­ ted with radial tires of the
same type, size (rolling cir­
cumference) and the same
tread pattern. Driving with different tires reduces vehi­
cle handling and can lead to
a loss of control.
-If the spare tire is not the
same as the tires that are
mounted on the vehicle -for
example with winter tires -
only use the spare tire for a
short period of time and
drive with extra care. Refit
the normal road wheel as soon as safely possible.
-Never drive faster than the maximum speed for which
the tires on your vehicle are
rated because tires that are
driven faster than their rat­
ed speed can fail suddenly.
-Overloading tires cause heat build-up, sudden tire fail ­
ure, including a blowout
..