traction control AUDI A4 2021 Owner´s Manual

Driving dynamic

There is a malfunction in the electronic steering
lock. Drive immediately to an authorized Audi
dealer or authorized Audi Service Facility to have
the malfunction repaired.
Dynamic steering: correcting steering wheel
position
The steering is reinitializing. The steering wheel
will move easily after starting the vehicle. Reiniti-
alization might be necessary if the steering wheel
was moved while the engine was switched off.
The display turns off if the initialization was suc-
cessful.

ZA\ WARNING
Do not tow your vehicle if there is a malfunc-
tion in the electronic steering lock because
this increases the risk of an accident.
@) Tips
— If there is a malfunction, the steering wheel
may be crooked when driving straight.
—Ifthe Ba or fal indicator light only stays on
for a short time, you may continue driving.

All wheel drive (quattro)
Applies to: vehicles with all wheel drive
The all-wheel drive system distributes the driving
power variably to the front and rear axle to im-
prove the driving characteristics. It works togeth-
er with selective wheel torque control, which can
activate when driving through curves
=> page 113.
Applies to: vehicles with quattro ultra: If the driv-
ing situation does not require all wheel drive,
then the rear section of the drivetrain will decou-
ple to save fuel. The system constantly deter-
mines and anticipates if all wheel drive is needed.
This allows the rear drivetrain to recouple shortly
before it is needed.
The all-wheel drive system is designed for high
engine power. Your vehicle is exceptionally pow-
erful and has excellent driving characteristics
both under normal driving conditions and on
112
snow and ice. Always read and follow safety pre-
cautions > A\.

ZA WARNING
— Even in vehicles with all wheel drive, you
should adapt your driving style to the cur-
rent road and traffic conditions to reduce
the risk of an accident.
—The braking ability of your vehicle is limited
to the traction of the wheels. In this way, it
is not different from a two wheel drive vehi-
cle. Do not drive too fast because this in-
creases the risk of an accident.
— Note that on wet streets, the front wheels
can “hydroplane’” if driving at speeds that
are too high. Unlike front wheel drive
vehicles, the engine RPM does not increase
suddenly when the vehicle begins hydro-
planing. Adapt your speed to the road condi-
tions to reduce the risk of an accident.
Sy amet
Applies to: vehicles with sport differential

The sport differential distributes the drive power
to the rear axle based on the situation. The goal
is a high level of agility and ability to accelerate
on curves. The vehicle is very responsive to steer-
ing. The settings depend on the selected Audi
drive select* mode.
WEE Tel
it} All-wheel drive: malfunction! You can con-
tinue driving. Please contact Service
Drive immediately to an authorized Audi dealer
or authorized Audi Service Facility to have the
malfunction repaired.
it} Sport differential: malfunction! Please con-
tact Service
Drive immediately to an authorized Audi dealer
or authorized Audi Service Facility to have the
malfunction repaired.
it} All-wheel drive: too hot. Please adapt driv-
ing style. See owner's manual

Wheels

be five 150 lbs. passengers in
your vehicle, the amount of
available cargo and luggage
load capacity is 650 lbs.
(1400-750 (5 x 150) = 650
lbs.)
5. Determine the combined
weight of luggage and cargo
being loaded on the vehicle.
That weight may not safely ex-
ceed the available cargo and
luggage load capacity calculat-
ed in Step 4.
6. If your vehicle will be towing a
trailer, load from your trailer
will be transferred to your vehi-
cle. Consult this manual to de-
termine how this reduces the
available cargo and luggage
load capacity of your vehicle.
>Check the tire sidewall
(=> page 236, fig. 165) to deter-
mine the designated load rating
for a specific tire.
Wheel bolts and rims
Wheel bolts
Wheel bolts must be clean and loosen/tighten
easily.
Rims
Rims with a bolted rim ring* or with bolted wheel
covers* consist of multiple pieces. These compo-
nents were bolted together using special bolts
and a special procedure. You must not repair or
disassemble them > A\.
250

ZA WARNING
Wheel bolts that are tightened or repaired in-
correctly can become loose and result in loss
of vehicle control, which increases the risk of
an accident. For the correct tightening specifi-
cation, see > page 266, Finishing.
— Always keep the wheel bolts and the threads
in the wheel hub clean and free of grease.
— Only use wheel bolts that fit the rim.
— Always have damaged rims repaired by an
authorized Audi dealer or authorized Audi
Service Facility. Never repair or disassemble
rims yourself, because this increases the risk
of an accident.
Winter tires significantly improve the vehicle's
handling when driving in winter conditions. Be-
cause of their construction (width, compound,
tread pattern), summer tires provide less traction
on ice and snow.

> Use winter tires on all four wheels.
> Only use winter tires that are approved for your
vehicle.
> Please note that the maximum permitted
speed may be lower with winter tires > A\ in
General information on page 235. An author-
ized Audi dealer or authorized Audi Service Fa-
cility can inform you about the maximum per-
mitted speed for your tires.
> Check the tire pressure after installing wheels
=> page 245.
The effectiveness of winter tires is reduced great-
ly when the tread is worn down to a depth of
0.16 in (4 mm). The characteristics of winter tires
also decrease greatly as the tire ages, regardless
of the remaining tread.
@) For the sake of the environment
Reinstall summer tires at the appropriate
time, because they provide better handling
when roads are free of snow and ice. Summer
tires cause less road noise, tire wear, and fuel
consumption.

8W1012721BC
Wheels

@) Tips
You can also use all season tires instead of
winter tires. Please note that in some coun-
tries where winter tires are required, only win-
ter tires with the 44 symbol may be permit-
ted.
Snow chains improve both driving and braking in
winter road conditions.
> Only install snow chains on the front wheels.
> Check and correct the seating of the snow
chains after driving a few feet, if necessary. Fol-
low the instructions from the manufacturer.
> Note the maximum speed of 30 mph
(50 km/h). Observe the local regulations.
Use of snow chains is only permitted with certain
rim/tire combinations due to technical reasons.
Check with an authorized Audi dealer or author-
ized Audi Service Facility to see if you may use
snow chains.
Use fine-mesh snow chains. They must not add
more than 0.53 in (13.5 mm) in height, including
the chain lock.
You must remove the snow chains on roads with-
out snow. Otherwise, you could impair driving
ability and damage the tires.

ZA WARNING
Using incorrect snow chains or installing snow
chains incorrectly can result in loss of vehicle
control, which increases the risk of an acci-
dent.
@) Note
Snow chains can damage the rims and wheel
covers* if the chains come into direct contact
with them. Remove the wheel covers* first.
Use coated snow chains.
@ Tips
When using snow chains, it may be advisable
to limit the ESC > page 114.

Low-profile tires
Applies to: vehicles with low-profile tires
Compared to other tire/rim combinations, low-
profile tires offer a wider tread surface anda
larger rim diameter with shorter tire sidewalls.
This results in an agile driving style. However, it
may reduce the level of comfort and increase
road noise when driving on roads in poor condi-
tion.
Low-profile tires can become damaged more
quickly than standard tires when driving over
large bumps, potholes, manhole covers, and
curbs. Therefore, it is particularly important to
maintain the correct tire pressure > page 245.
To reduce the risk of damage to the tires and
rims, drive very carefully on poor roads.
Check your wheels regularly every 2,000 mi
(3,000 km) for damage. For example, check for
bulges/cracks on the tires or deformations/cracks
on the rims.
After a heavy impact or damage, have the tires
and rims inspected or replaced immediately by
an authorized Audi dealer or authorized Audi
Service Facility.
Low-profile tires can wear out faster than stand-
ard tires.
Uniform tire quality grading
— Tread wear
— Traction AAABC
— Temperature ABC
Quality grades can be found where applicable on
the tire side wall between tread shoulder and
maximum section width > page 236, fig. 165.
For example: Tread wear 200, Traction AA, Tem-
perature A.
All passenger car tires must conform to Federal
Safety Requirements in addition to these grades.
Tread wear
The tread wear grade is a comparative rating
based on the wear rate of the tire when tested
251
>

Wheels

under controlled conditions on a specified gov-
ernment test course.
For example, a tire graded 150 would wear one
and one half (1 1/2) times as well on the govern-
ment course as a tire graded 100.
The relative performance of tires depends upon
the actual conditions of their use, however, and
may depart significantly from the norm due to
variations in driving habits, service practices and
differences in road characteristics and climate.
Traction
The traction grades, from highest to lowest, are
AA, A, Band C. Those grades represent the tire's
ability to stop on wet pavement as measured un-
der controlled conditions on specified govern-
ment test surfaces of asphalt and concrete. A tire
marked C may have poor traction performance
oA.
Temperature
The temperature grades are A (the highest), B,
and C, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions on
a specified indoor laboratory test wheel.
Sustained high temperature can cause the mate-
rial of the tire to degenerate and reduce tire life,
and excessive temperature can lead to sudden
tire failure > A.
The grade C corresponds to a level of perform-
ance which all passenger car tires must meet un-
der the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels
of performance on the laboratory test wheel than
the minimum required by law.

Z\ WARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor-
nering, hydroplaning or peak traction charac-
teristics.

252

AN WARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, or excessive loading, either separately or
in combination, can cause heat buildup and
possible tire failure.

ZA\ WARNING
Temperature grades apply to tires that are
properly inflated and not over or underinflat-
ed.

Tire pressure monitoring
system
(1) General notes
Each tire, including the spare (if provided),
should be checked monthly when cold and inflat-
ed to the inflation pressure recommended 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 pressure la-
bel, you should determine the proper tire infla-
tion pressure for those tires).
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system
(TPMS)
that illuminates a low tire pressure tell-
tale when one or more of your tires is significant-
ly under-inflated. Accordingly, when the low tire
pressure telltale illuminates, you should stop and
check your tires as soon as possible, and inflate
them to the proper pressure. Driving on a signifi-
cantly under-inflated tire causes the tire to over-
heat and can lead to tire failure. Under-inflation
also reduces fuel efficiency and tire tread life,
and may affect the vehicle's handling and stop-
ping ability.
Please note that the TPMS is not a substitute for
proper tire maintenance, and it is the driver's re-
sponsibility to maintain correct tire pressure,
even if under-inflation has not reached the level
to trigger illumination of the TPMS low tire pres-
sure telltale.