2021 AUDI S4 Owners Manual

8W1012721BC
Wheels

Gross Axle Weight Rating
(“GAWR’”)
means the load-carrying capacity
of a single axle system, measured
at the tire-ground interfaces.
Gross Vehicle Weight Rating
(“GVWR”)
means the maximum total loaded
weight of the vehicle.
Groove
means the space between two ad-
jacent tread ribs.
Load rating (code)
means the maximum load that a
tire is rated to carry for a given in-
flation pressure. You may not find
this information on all tires be-
cause 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 infla-
tion pressure to which a tire may
be inflated. Also called “maxi-
mum inflation pressure.”
Normal occupant weight
means 150 lbs. (68 kilograms)
times the number of occupants
seated in the vehicle up to the to-
tal seating capacity of your vehi-
cle.
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 be-
tween the exteriors of the side-
walls of an inflated tire, including
elevations due to labeling, deco-
rations, or protective bands or
ribs.
Ply
means a layer of rubber-coated
parallel cords.
239

Wheels

Production options weight
means the combined weight of
those installed regular production
options weighing over 5 lbs.
(2.3 kg) in excess of those stand-
ard items which they replace, not
previously considered in curb
weight or accessory weight, in-
cluding 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 238, Cold tire infla-
tion pressure.
Reinforced tire
means a tire designed to operate
at higher loads and at higher in-
flation pressures than the corre-
sponding standard tire. Rein-
forced tires may be identified as
“XL”, “xl”, “EXTRA LOAD”, or “RF”
on the sidewall.
240
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 pur-
chase new tires to match the new
rim diameter.
Rim size designation
means rim diameter and width.
Rim width
means nominal distance between
rim flanges.
Sidewall
means that portion of a tire be-
tween the tread and bead.
Speed rating (letter code)
means the speed at which a tire is
designed to be driven for extend-
ed periods of time. The ratings
range from 93 mph (150 km/h)
to 186 mph (298 km/h) > table
on page 236. You may not find
this information on all tires be-
cause it is not required by law.
The speed rating letter code,
where applicable, is molded on
the tire sidewall and indicates the >

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Wheels

maximum permissible road
speeds. See also > A in General
information on page 235.
Tire pressure monitoring
system
means a system that detects
when one or more of a vehicle's
tires are underinflated and illumi-
nates a low tire pressure warning
telltale.
Tread
means that portion of a tire that
comes into contact with the road.
Tread separation
means pulling away of the tread
from the tire carcass.
Treadwear indicators (TWI)
means the projections within the
principal grooves designed to give
a visual indication of the degrees
of wear of the tread. See
=> page 244, Treadwear indicator
for more information on measur-
ing tire wear.
Uniform Tire Quality Grading
is a tire information system devel-
oped by the United States Nation-
al Highway Traffic Safety Adminis-
tration (NHTSA) that is designed
to help buyers make relative com-
parisons among tires. The UTQG is
not a safety rating and not a guar-
antee that a tire will last fora
prescribed number of miles (kilo-
meters) or perform ina certain
way. It simply gives tire buyers
additional information to com-
bine with other considerations,
such as price, brand loyalty and
dealer recommendations. Under
UTQG, tires are graded by the tire
manufacturers in three areas:
treadwear, traction, and tempera-
ture resistance. The UTQG infor-
mation on the tires, molded into
the sidewalls.
U.S. DOT Tire Identification
Number (TIN)
This is the tire’s “serial number”.
It begins with the letters “DOT”
and indicates that the tire meets
all federal standards. The next
two numbers or letters indicate
the plant where it was manufac-
tured, and the last four numbers
represent the week and year of
manufacture. For example,
DOT... 2220...
means that the tire was produced
in the 22nd week of 2020. The
other numbers are marketing co-
des that may or may not be used >
241

Wheels

by the tire manufacturer. This in-
formation is used to contact con-
sumers if a tire defect requires a
recall.
Vehicle capacity weight
means the rated cargo and lug-
gage load plus 150 lbs. (68 kilo-
grams) times the vehicle's desig-
nated seating capacity.
Vehicle maximum load on the
tire
means that load on an individual
tire that is determined by distrib-
uting to each axle its share of the
maximum loaded vehicle weight
and dividing by two.
Vehicle normal load on the tire
means that load on an individual
tire that is determined by distrib-
uting to each axle its share of the
curb weight, accessory weight,
and normal occupant weight (dis-
tributed in accordance with > ta-
ble on page 247) and dividing by
two.
Occupant loading and distri-
bution for vehicle normal load
for various designated seating
capacities
Refer to the tire inflation pressure
label > page 245, fig. 168 for the
242
number of seating positions. Re-
fer to the table > table on
page 247 for the number of peo-
ple that correspond to the vehicle
normal load.
New tires or wheels
Audi recommends having all work
on tires or wheels performed by
an authorized Audi dealer or au-
thorized Audi Service Facility.
These facilities have the proper
knowledge and are equipped with
the required tools and replace-
ment parts.
>New tires do not yet have the
optimal gripping properties.
Drive carefully and at moderate
speeds for the first 350 miles
(500 km) with new tires.
> Only use tires with the same de-
sign, size (rolling circumfer-
ence), and as close to the same
tread pattern as possible on all
four wheels.
>Do not replace tires individually.
At least replace both tires on the
same axle at the same time.
> Audi recommends using Audi
Genuine Tires. If you would like
to use different tires, please
note that the tires may perform >

8W1012721BC
Wheels

differently even if they are the
same size > A.
>If you would like to equip your
vehicle with a tire and rim com-
bination that is different from
what was installed at the facto-
ry, consult with an authorized
Audi dealer or authorized Audi
Service Facility before making a
purchase > A.
Because the spare tire® is differ-
ent from the regular tires instal-
led on the vehicle (such as winter
tires or wide tires), only use the
spare tire* temporarily in case of
emergency and drive carefully
while it is in use. It should be re-
placed with a regular tire as soon
as possible.
Applies to: vehicles with all wheel
drive: All four wheels must be
equipped with tires that are the
same brand and have the same
construction and tread pattern so
that the drive system is not dam-
aged by different wheel speeds.
For this reason, in case of emer-
gency, only use a spare tire* that
is the same circumference as the
regular tires.


Z\ WARNING
—Do not use steel rims that are
17 inches or larger. Otherwise,
damage to the vehicle and an
accident could result.
—Only use tire/rim combina-
tions and suitable wheel bolts
that have been approved by
Audi. Otherwise, damage to
the vehicle and an accident
could result.
—For technical reasons, it is not
possible to use tires from oth-
er vehicles. In some cases, you
cannot even use tires from the
same vehicle model.
—Make sure that the tires you
select have enough clearance
to the vehicle. Replacement
tires should not be chosen
simply based on the nominal
size, because tires with a dif-
ferent construction can differ
greatly even if they are the
same size. If there is not
enough clearance, the tires or
the vehicle can be damaged
and this can reduce driving
safety and increase the risk of
an accident.

243

Wheels


—Only use tires that are more
than six years old when abso-
lutely necessary and drive
carefully when doing so.
—Do not use run-flat tires on
your vehicle. Using them when
not permitted can lead to ve-
hicle damage or accidents.
—If you install wheel covers on
the vehicle, make sure they al-
low enough air circulation to
cool the brake system. If they
do not, this could increase the
risk of an accident.


Tire wear and damage
N
LA

Fig. 166 Tire profile: treadwear indica-
tor
Tire wear
Check the tires regularly for wear.

D Obey any applicable regulations in the
country where the vehicle is being oper-
ated.
244
—Inflation pressure that is too low
or high can increase tire wear
considerably.
—Driving quickly through curves,
rapid acceleration, and heavy
braking increase tire wear.
—Have an authorized Audi dealer
or authorized Audi Service Facili-
ty check the wheel alignment if
there is unusual wear.
—Have the wheels rebalanced if an
imbalance is causing noticeable
vibration in the steering wheel.
If you do not, the tires and other
vehicle components could wear
more
quickly.
Treadwear indicator
Original equipment tires contain
treadwear indicators in the tread
pattern, which are bars that are
1/16 inch (1.6 mm) high and are
spaced evenly around the tire per-
pendicular to the running direc-
tion > fig. 166. The letters “TWI”
or triangles on the tire sidewall
indicate the location of the tread-
wear indicators.
The tires have reached the mini-
mum tread depth !) when they >

8W1012721BC
Wheels

have worn down to the treadwear
indicators. Replace the tires with
new ones > A.
Tire rotation
Rotating the tires regularly is rec-
ommended to ensure the tires
wear evenly. To rotate the tires,
install the tires from the rear axle
on the front axle and vice versa.
This will allow the tires to have
approximately the same length of
service life.
For unidirectional tires, make sure
the tires are installed according to
the running direction indicated on
the tire sidewall > page 266.
Hidden damage
Damage to tires and rims can of-
ten occur in locations that are hid-
den. Unusual vibrations in the ve-
hicle or pulling to one side may
indicate that there is tire damage.
Reduce your speed immediately.
Check the tires for damage. If no
damage is visible from the out-
side, drive slowly and carefully to
the nearest authorized Audi deal-
er or authorized Audi Service Fa-
cility to have the vehicle inspect-
ed.


Z\ WARNING
Tread that has worn too low or
uneven tread depths on the
tires can reduce driving safety.
This can increase the risk of an
accident because it has a nega-
tive effect on handling, driving
through curves, and braking,
and because it increases the
risk of hydroplaning when driv-
ing through deep puddles.

Micmac)


B8W-0152 Kf)

Fig. 167 Driver's side B-pillar: tire pres-
sure label




B8K-1151
SEATING CAPACITY TOTAL pay FRONT nA On NOMBRE DE PLACES TOTAL AVANT ARRIERE
= a.
TIRE SIZE COLD TIRE PRESSURE
PRESSION DES PNEUS A FROID PNEU _| DIMENSIONS FRONT
AVANT, a KPA, Ml PSI
REAR
ARRIERE Wa KPA, Ml PSI
‘SPARE
DE SECOURS Ma KPA, Ml PSI





Fig. 168 Tire pressure label
The correct tire pressure for tires
installed at the factory is listed on
a label. The label is located on the >
245

Wheels

B-pillar (driver's side) > fig. 167,
> fig. 168. The location may vary
depending on the model.
Use the tire pressure specified for
a normal vehicle load when the
vehicle is partially loaded > table
on page 247. If driving the vehi-
cle when fully loaded, you must
increase the tire pressure to the
maximum specified pressure > A.
Checking and correcting tire
pressure
>Check the tire pressure at least
once per month and also check it
before every long drive.
> Always check the tire pressure
when the tires are cold. Do not
reduce the pressure if it increas-
es when the tires are warm.
>Refer to the sticker > fig. 168
for the correct tire pressure.
>Correct the tire pressure if nec-
essary.
>Save the changed tire pressure
> page 254.
> Check the pressure in the spare
tire (compact spare tire)*. Al-
ways maintain the maximum
temperature that is specified for
the tire.
246


Z\ WARNING
Always adapt the tire pressure
to your driving style and the ve-
hicle load.
—Overloading can lead to loss of
vehicle control and increase
the risk of an accident. Read
and follow the important safe-
ty precautions in > page 248.
—The tire must flex more if the
tire pressure is too low or if
the vehicle speed or load are
too high. This heats the tire up
too much. This increases the
risk of an accident because it
can cause the tire to burst and
result in loss of vehicle con-
trol.
—Incorrect tire pressure increas-
es tire wear and has a negative
effect on driving and braking
behavior, which increases the
risk of an accident.

@) Note
Replace lost valve caps to re-
duce the risk of damage to the
tire valves.
(*) For the sake of the envi-
ronment
Tire pressure that is too low in-
creases fuel consumption.