2015 AUDI A3 four wheel drive

78 Driving
When stopping at a traffic signal or stopping in city traffic, the parking brake can be ap­
plied. The vehicle does not have to be held
with the brake pedal. The parking brake elimi­ nates the tendency to creep when a selector
lever position is engaged . As soon as you
press the accelerator pedal, the parking brake
releases automatically and the vehicle starts
to move.
Starting on slopes
When starting on inclines, the hill start assist
prevents the vehicle from unintentionally roll­
ing back. The braking force of the parking
brake is not released until sufficient driving
force has been built up at the wheels.
(D Tips
For safety reasons, the park ing brake is re­
leased automatically only when the driv­
er 's safety belt is fastened and the driver 's
door is locked.
Emergency braking function
This is used if the convention brake system
fails or locks up.
~ To brake your vehicle in an emergency, pull
the @switch
¢ page 76, fig. 68 and hold it
pulled.
~ As soon as you release the@ switch or ac-
celerate, the braking process stops.
Pulling and holding the @switch while driv­
ing at a speed of about 2 mph (3 km/h) or
higher initiates the emergency braking func­
tion. The vehicle is braked at all four wheels by activating the braking hydraulics. The brake
performance is similar to heavy braking.¢.&
To help prevent activating the emergency braking by mistake, an audible warning tone
(buzzer) sounds when the @switch is pulled.
E mergency braking stops as soon as the@
switch is released or the accelerator pedal is pressed.
A WARNING
Emergency braking should only be used in
an emergency, when the normal brake
pedal has failed or the brake pedal is ob­
structed . During emergency braking, your
vehicle will brake similar to heavy braking .
ESC and the associated components (ABS,
ASR, EDL) cannot overcome the laws of
physics. In corners and when road or
weather conditions are bad, a full brake
application can cause the vehicle to skid or
the rear end to break away, which increas­
es the risk of an accident.
Hill hold
Applies to vehicles: wit h Hill Hold
Hill hold makes it easier to start on hills.
Requirement: The driver door must be closed
and the engine must be running.
The system is activated when the brake pedal
is pressed while the vehicle is stationary.
To prevent the vehicle from rolling back when
starting, the brake power is held for a brief
moment after releasing the brake pedal. Dur­
ing this time, you can easily begin to move
your vehicle.
A WARNING ......_
- The intelligent technology of Hill Hold
cannot overcome the limitations im­
posed by natural physical laws. The in­
creased comfort offered by Hill Hold
should not cause you to take safety risks .
- Hill Hold cannot hold the vehicle in all
hill start situations (for example, if the
ground is slippery or icy).
- If you do not begin moving immediately
after releasing the brake pedal, the vehi­
cle could begin to roll backward under
certain circumstances. Press the brake
pedal or set the parking brake immedi­
ately.
- If the engine "stalls", press the brake
pedal or set the parking brake immedi­
ately.
-

186 Smart T echnol ogy
correctly. ED L will switch on again automati ­
cally when conditions have returned to nor­
mal.
Electroni c inte raxle diff ere ntial lo ck */
s e le ct ive w heel t orqu e cont rol *
The electronic interaxle differential lock (front
wheel drive) or the selective wheel torque
contro l (all wheel drive) operates when driving
through curves. The front whee l on the inside
of the curve or both wheels o n the inside of
the curve are braked selectively as needed .
This minimizes s liding in the front wheels and
a llows for more precise driving through
curves. The app licab le system may not acti­
vate when driving in wet or snowy conditions .
Post-collision bra ke ass ist
"Post-collision brake assist" can ass ist the
driver during a collision by reducing the dan­
ge r of slipp ing and further co llision and by au­
tomatic braking.
"Post-collision brake assist" functions during
front, side and rear collis ions when the a irbag
control module a detects a trigger level and
the co llision takes place at a dr iv ing speed
faster than 6 mph (10 km/h). The braking of
the vehicle happen automatically via the ESC
as long as the ESC, the hydraulic brake sys­
tem, and the vehicle electrical system are not
damaged from the coll ision.
The fo llowing activ ities override the automat­
ic braking during a collision:
- If the dr iver presses the accelerator peda l.
T here is no a utomatic braking.
- When the force on the press brake pedal is
stronger than the b raking force initiated by
the system . The vehicle is manually braked .
- When the ESC is damaged and the "post­
collision brake assist" is not availab le.
A WARNING
- The ESC, ABS, ASR, EDL, electron ic inter­
axle d ifferential lock or select ive wheel
torque control cannot overcome the laws
of physics. This is espec ially important
on sl ippery o r wet roads.
If the systems
begin acting to stabili ze your veh icle, you
should immediately alter your speed to
match the road and traffic conditions . Do
not let the increased safety prov ided
tempt you into tak ing risks. This could
increase your risk of a collision.
- Please note the risk of a collision increas­
es when driving fast, especially through
curves and on slippery or wet roads, and
when dr iv ing too close to objects ahead .
ESC, ABS, the brake assist system, EDL,
electronic interaxle differentia l lock or
selective whee l to rque control cannot
p revent coll is ions.
- Press the acce lerator pedal carefully
when acce le rat ing o n even, slippe ry sur­
f a ces such as ice and snow. The drive
wheels can spin even when these control
systems are installed and this can affect
driving stability and increase the risk of a
col lision.
(D Tips
- ABS and ASR only function correc tly
when all four wheels are eq uipped w ith
identical tires. Different t ire sizes can
lead to a reduction in engine power.
- Yo u may hear noises when the systems
described are working .
- If the
DJ or m] (USA models) !II] (Cana ­
da mode ls) indicator light appears, there
may be a malfunction
¢ page 22.

190 Smart T echnol ogy
Drive to an authorized Audi dea le r or qualified
repair facility immediately to have the ma l­
function corrected .
_& WARNING
Have the system malfunction repaired as
soon as possible by an authorized Audi
dealer or qualified repair facility, as th is in ­
creases the risk of an acc ident.
(D Tips
If the . or ,1:-ij indicator light on ly stays
on for a short time , you may continue driv­
ing .
ALL wheel drive
(quattro)
Appl ies to vehicles: wit h all whee l drive
In all wheel drive, all four wheels are pow ­
ered .
General information
In all wheel drive, the driving power is divided
between all four wheels. This happens auto­
mat ica lly depending on you r driv ing behavior
as we ll as the current road conditions. Re fer
to
¢ page 185, Electronic stabilization con ­
trol (ESC) .
The all wheel drive concept is designed for
h igh engine power . Yo ur vehicle is exception­
a lly powerful and has excellent driving charac ­
teristics bot h under normal driving conditions
and on snow and ice . A lways read and fo llow
safety precautions
c> & .
Wint er t ire s
By using all wheel drive, your vehicle has good
forward motion with standard tires in winter
conditions . However, in winter we recommend
using winter or all season t ires on
all four
wheels, because this will improve the braking
effec t.
Snow cha in s
If there are snow chain laws, snow chains
must also be used on vehicles with a ll whee l
drive
c> page 241, Snow chains.
Replacing tire s
For vehicles with a ll wheel d rive, only wheels
with the same ro lling circumference should be
u sed. Avoid wheels with different tread
depths ¢
page 236 .
Offroad vehicle?
You r A udi is not a n offroad vehicle -there is
not enoug h ground clearance. For this reason ,
avoid difficu lt terrain. Refer to
c::> page 266.
A WARNING ~
- Also, in vehicles with a ll w heel drive,
adapt your driving sty le to the c urrent
road and traffic cond itions. Do not let
the increased safety provided tempt you into taking risks .
- The braking ability of your veh icle is lim­
ited to the traction of the wheels. In this
way, it is not different from a two wheel d rive vehicle . Do not be tempted to ac­
celerate to a high speed when the road is
slippe ry this inc reases the r is k of an acci­
dent.
- Note that o n wet s treets, the front
wheels ca n "hydrop lane " if driv ing at
speeds that are too high. Unlik e fron t
wheel drive vehicles, the engine does not rev higher sudden ly when the vehicle be­
g ins hydroplaning. For this reason, pay
attention to the road conditions regard­ less of your speed.
Energy management
The starting ability is optimized
The energy management system manages
the electrical energy distribution and optimiz­
es the availability of electrical energy for
starting the engine.
When a vehicle with a conventiona l energy
system is not d riven for a long time , the bat­
te ry is drained by equ ipment ( for example the
immobilizer) . In certain c ircumstances, there
cou ld may not be enough energy to start the
engine .
1J1-

228 Tires and wheels
Speed rating (letter code)
means the speed at wh ic h a tir e is des igned to
be d riven for extended per io d s of t ime. The
ratings range from 93 mph (150 km/h) to
186 mph (298 km/h) ¢page 237. You may
not find this in format ion on all tires because
it is not required by law.
The speed rating letter code, w here a pplica­
b le, is molded on the tire s idewa ll and indi­
cates the maxim um permissible road speeds
¢ &. in Winter tires on page 241.
Tire pressure monitoring sy stem
means a sys tem that detects when one or
mo re of a vehicle's t ires are under inflated and
il lum inates a low t ire p ress ure warn ing te ll­
tale.
Tread
means t hat port ion of a tire tha t comes into
con tact w it h t he road.
Tread separation
means pull ing away of the t read from the t ire
car cass .
Treadwear indicators (TWI)
means t he p rojections withi n the pr inc ipal
g rooves desig ned to give a v isua l ind ication of
the deg rees of wear of the tre ad . See
¢ pag e 235, Tread W ear Indicator (TWI) for
mo re in format io n on measu ring tire we ar.
Uniform Tire Quality Grading
is a ti re i nfo rmation system developed by the
United States Nat io nal Highway Traffic Safety
Admi nistration (N HTSA) that is designed to
h e lp buye rs make re lative compa risons among
tires. The UT QG i s n ot a safety r ating an d not a
g ua ran tee t hat a tir e will las t fo r a presc ribed
n umber of m iles (kilome ters) or pe rform in a
certain way. It s imply gives ti re b uye rs addi­
tional information to combine with other con -s
iderations, such as p rice , brand loya lty and
dealer recommendations. Un der UTQG, tires
are grade d by the t ire manufacturers in three
areas : treadwea r, traction, and temperature
resistance. The UTQG informat ion on the tires,
molded into the sidewalls .
U.S. DOT Tire Identification Number (TIN)
T his is the tire's "se ria l numbe r" . It be gins
with the letters "DOT" and ind icates that the
t ir e meets all federa l standards. The next two
numbers o r letters ind icate the plant where it
was ma nufactu red, and the last four numbe rs
represe nt th e week and year of ma nufact ure.
F or exampl e,
DOT ... 4513 ...
means that the tire was produced in t he 45th
wee k of 2013. The other numbers are market­
ing codes that may or may not be used by the
t ire manufacturer. This information is used to
contact consumers i f a tire defect requires a
r ecall .
Vehicle capacity weight
means the rated cargo and luggage load plus
150 lbs. (68 k ilograms) times the vehicle's to­
ta l seating capacity as listed on the label lo­
cated on the driver's side B-p illa r.
Vehicle maximum lo ad on the tire
means that load on an individua l tire that is
determined by distributing to eac h ax le its
share of the maxim um loaded vehicle weight
and divid ing by two .
Vehicle normal load on the tire
means that load o n an individua l t ir e that is
determined by distrib uting to eac h ax le its
share of the curb weight, accessory weight, and normal occ upant weig ht (d istr ibuted in
accordance with tab le below¢ page 229)
and divid ing by two .

and luggage load capacity
calculated in Step 4.
6 . If your vehicle will be towing
a trailer, load from your trail­
er will be transferred to your
vehicle. Consult this manual
to determine how this re­ duces the available cargo
and luggage load capacity of
your vehicle.
~check the tire sidewall
(¢page 236, fig. 160) to de­
termine the designated load
rating for a specific tire.
Tire service life
The service life of tires depends on a lot of
different things including proper installation
and balan cing, correct tire pressure and driv­
ing style.
Fig. 158 T ir e tread: tread wea r ind icators (TWI)
Fig. 159 Rotat ing t ires for more even wea r
Tires and wheels 235
Tread Wear Indicator (TWI)
The orig inal tires on your vehicle have
1/16 inch ( 1.6 mm) hig h "wear indicators"
r:::>fig. 158 run ning across the tread. Depend­
ing on the make, there will be six to eight of
them evenly placed around the tire. Marks on
the tire sidewall (for examp le "TWI" or other
symbols) indicate the positions of the tread
wear indicators . Worn tires must be replaced .
D ifferent figures may apply in other countr ies
¢ Lr:,. .
Tire pressure
Incorrect t ire pressure causes premature wear
and can cause sudde n tire blow-out. For this
reason, tire pressure must be checked at least
once a month
r::> page 231.
Driving style
Driving fast around curves , heavy acce lerat ion
and hard braking increase tire wear .
Rotating tires for more even wear
For all four tires on your vehicle to have the
same service life, we recommend that the
front and rear tires are rotated according to
the tire manufacturer's suggested tire rota­
tion intervals. Please remember the follow­
i ng:
- Tire rotation intervals may differ from the
veh icle service intervals outlined in your
Warranty
& Maintenance booklet.
- The longer one tire is used in one location
on the vehicle, the more it wears at certain
points; therefore, we recommend that you
follow the tire manufact urer's suggested
tire rotation intervals.
- Ve hicl es w ith front -wheel dr ive experience
more tread wear on the fro nt wheels com­
pared to a ll-wheel drive (quattro) .
- Please rotate tires as shown
r:::> fig . 159 .
-Extra care must be taken when rotating di-
rection-specific tires
r::> page 253 .
Wheel balancing
The wheels on new vehicles are balanced .
However, various s ituations during everyday
driv ing can cause them to become

Driving with different tires reduces vehi­
cle handling and can lead to a loss of
control.
- If the spare ti re 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 nor­
mal road wheel as soon as safely possi­
ble.
- Never drive faster than the maximum
speed for which the tires on your vehicle
are rated because tires that are driven
faster than their rated speed can fail
suddenly.
- Overloading tires cause heat build-up,
sudden tire failure, including a blowout
and sudden deflation and loss of control.
- Temperature grades apply to tires that
are properly inflated and not over or un­
derinflated.
- For technical reasons it is not always
possible to use wheels from other
vehicles -in some cases not even wheels
from the same vehicle model.
- If you install wheel trim discs on the ve­
hicle wheels, make sure that the air flow
to the brakes is not blocked. Reduced air­
flow to the brakes can them to overheat, increasing stopping distances and caus­
ing a collision.
- Run flat tires may only be used on
vehicles that were equipped with them at the factory. The vehicle must have a
chassis designed for run flat tires. Incor­
rect use of run flat tires can lead to vehi­
cle damage or accidents. Check with an
authorized Audi dealer or tire specialist
to see if your vehicle can be equipped
with run flat tires. If run flat tires are used, they must be installed on all four
wheels. Mixing tire types is not permit­
ted.
(D Note
- For technical reasons, it is not generally
possible to use the wheel rims from oth-
Tires and wheels 239
er vehicles. This can hold true for wheels
of the same vehicle type.
- If the spare tire is different from the
tires that you have mounted on your ve­
hicle (for example winter tires or wide
profile tires), then use the spare tire for a
short period of time only and drive with
extra care. Replace the flat tire with the
tire matching the others on your vehicle as soon as possible.
- Never drive without the valve stem cap .
The valves could get damaged .
(® For the sake of the environment
Dispose of old tires in accordance with the
local requirements.
Uniform tire quality grading
-Tread wear
- Tract ion AA A B C
- Temperature AB C
Quality grades can be found where applicable
on the tire side wall between tread shoulder
and maximum section width
c;, page 236,
fig. 160.
For example: Tread wear 200, Traction AA,
Temperature A.
All passenger car tires must conform to Feder­
al 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
under controlled conditions on a specified
government test course.
For example, a tire graded ISO would wear
one and one half (11/2) times as well on the
government course as a tire graded 100.
The relative performance of tires depends upon the actual conditions of their use, how­
ever, and may depart significantly from the
norm due to variations in driving habits, serv­
ice practices and differences in road character-
istics and climate.
ll-
•
•
•

24 0 T ire s and wheel s
Traction
The traction grades, from highest to lowest,
are AA, A, Band
C. T hose grades represent the
tire's ability to stop on wet pavement as measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance
c:> .&. .
Te mp eratu re
The temperature grades are A (the highest),
B, and
C, representing the t ire's resistance to
the generation of heat and its ability to dissi­
pate heat when tested under con trolled condi­
tions on a specified i ndoor laboratory test
wheel.
Sustained high temperature can cause the
material of the tire to degenerate and reduce
tire life, and excessive temperature can lead
to sudden tire failure
c:> ,& .
The grade C corresponds to a level of perform­
ance which all passenger car tires must meet under the Federal Motor Veh icle Safety Stand­
ard No .
109 . Grades Band A represent h igher
l eve ls of pe rformance on the laboratory test
wheel than the m inimum required by law.
.&_ WARNING
T he traction grade assigned to this t ire is
based on stra ight-ahead braking traction
tests, and does not include acceleration,
cornering, hydrop laning o r peak traction
character istics.
A WARNING
The temperature grade for this tire is es ­
tablished for a t ire that is properly inflated
and not overloaded. Excessive speed, un­
derinflation, or excessive loading, either
separately or in combination, can cause
heat buildup and possible tire fa ilu re.
-
Winter tires
Winter tires can improve vehicle handling on
snow and ice . At temperatures below 45 °F
(7 °C) we recommend changing to winter
tires.
In some heavy snow areas, local governments
may require true w inter o r "snow" t ires, those
with very deeply cut tread . T hese tires should
o n ly be used in pairs and be installed on a ll
f o ur wheels . Make sure you purchase snow
t ir es that are the same size and construction
type as the othe r tires on yo ur vehicle.
If your vehicle is equ ipped w ith all-whee l
drive*, t his w ill improve traction during win ter
driv ing, even with the standard tires . Howev ­
er, we strongly recommend that you always
equip all four wheels on your vehicle w ith cor­
rect ly fitted winter tires or all-season t ires,
when winter road condit ions are expected.
This also improves the veh icle 's brak ing per­
formance and reduces stopping d istances .
Summer tires provide less grip on ice and
snow.
Winter tires (snow tires) must always be fitted on all fo ur whee ls .
Ask your au thorized A udi dealer or qualified
workshop for permit ted
winter ti re size s. Use
only radial winter tires .
Winter tires lose their effec tivenes s whe n the
tread is wo rn down to a depth o f
0.157 inch
(4 mm) .
Only d rive w ith w inter t ires under w inte r co n­
ditions. S umme r tir es handle bette r whe n
the re is no snow o r ice on the roads and the
temperature is above 45 °F (7 °C) .
If you have a flat ti re, see notes on spare
whee l
c:> page 236 .
Please always remember that winter tires may
have a lowe r speed rating than the tires o rigi­
nally i nstalled on your vehi cle at the time it
was manuf actu red. P lease see
c:> page 237,
Speed rating (Letter code)
for a lis ting o f the
speed rating lette r codes and the max imum
speed at which the tires can be driven . ..,.

24 4 T ire s and wheel s
signal low tire pressure as intended. TPMS
malfunctions may occur for a variety of rea­
sons, includ ing the installat ion of replace­
ment or a lternate tires or whee ls on the veh i­
cle that prevent the TPMS from funct ioning
properly . Always check the TPMS malfunct ion
telltale after replacing one or more t ires or
wheels on your veh icle to ensure that the re­
p lacement or a lternate tires and wheels allow
the TPMS to continue to function properly.
If the Tire Pressure Monitoring System
indicator appears
Applies to vehicles: with tire pressure monitoring system
The tire pressure indicator in the instrument
cluster informs you if the tire pressure is too
low or if there is a system malfunction.
F ig. 161 Ins trumen t cluste r: ind icato r light w it h m es­
s age
Using the ABS sensors, the tire pressure moni­
toring system compa res the tire tread circum­
ference and vibration characteristics of the in­
dividual tires .
If the pressure changes in one
or more tires, th is is indicated in the instru­
ment cluster display with an indicator light
IE and a message ¢ fig. 161 . If only one t ire
is affected, the location of that t ire will be in­
d icated. The message turns off after a few mi­
nutes. You can disp lay the message again
¢ page 28.
The tire pressures must be stored in the menu
d isplay aga in each time the pressures change
(switching between part ia l and full load pres­
sure) or after chang ing or replac ing a tire on
your ve hicle ¢
page 245. The tire pressure
monitoring system on ly monitors the ti re
press ure you have stored . You can find the rec­
ommended tire pressures for your vehicle on the
labe l on the driver's doo r pillar
¢ page 229 .
Tire tread circumference and vib ration charac­
teristics can change and cause a tire pressure
warning if:
- I f the tire pressure in one or more ti res is
t oo low.
- The tire has structural damage.
- The tire was replaced or the t ire pressure
changed and it was not stored again
¢ page 245.
-The spare tire is installed .
Indicator lights
IE -Loss of pressure in at least one tire ¢ .&. .
Check the tires and replace or repair if neces­
sary. Check/correct the pressures of all four
t ires . Then store the t ire pressures in the
menu display
¢ page 245.
Ill (T ire Pressure Monitoring System) T ire
pre ssure: S ystem mal function!. Ifm:!
ap­
pears afte r switching the ignition on or w hile
driv ing and the [ti] indicato r light in the in­
strument cluster b links for app rox imately one
minute and then stays on , the re is system
malfu nction . Check/cor rect the p ress ures of
all four tires and store them¢
page 245. If
t h e indicator lig ht does turn off or tu rns on
again after a short pe riod of time, drive to
your authori zed Aud i dea ler or qualified repair
facility immed iately to have the malfunction
corrected .
A WARNING
--- If the tire pressure ind icator appears in
the instrument cluster display , one or
mo re of your t ires is sign ifi cant ly unde r­
i n flated. Reduce yo ur speed immedi ately
an d avoid any hard steer ing or b rak ing
maneuvers. Stop as soon as possib le and
check the tires and their pressures. In­
f late the tire pressure to the proper pres­
sure as indicated on the vehicle's tire
pressure labe l
¢page 229. Driving on a
significantly under-i nflated tire causes
the t ire to overheat and can lead to ti re
fa ilur e. Unde r-inflation also is li kely to