2008 AUDI A4 four wheel drive

Contents3
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Safety
. . . . . . . . . . . . . . . . . . . . . . .
Safe driving
. . . . . . . . . . . . . . . . . . . .
General notes . . . . . . . . . . . . . . . . . .
Correct sitting positions . . . . . . . .
Pedal area . . . . . . . . . . . . . . . . . . . . .
Stowing luggage safely . . . . . . . . .
Seat belts
. . . . . . . . . . . . . . . . . . . . . .
Why is it so important to use seat
belts? . . . . . . . . . . . . . . . . . . . . . . . . .
Forces acting in a collision . . . . . .
How to wear seat belts properly .
Belt tensioners . . . . . . . . . . . . . . . . .
Airbag system
. . . . . . . . . . . . . . . . .
Description of airbag system . . . .
Front airbags . . . . . . . . . . . . . . . . . .
Side airbags . . . . . . . . . . . . . . . . . . .
Head-protection airbags
(sideguard) . . . . . . . . . . . . . . . . . . . .
Deactivating the front passenger's
airbag via the key-operated switch
Child safety
. . . . . . . . . . . . . . . . . . . .
Points to remember if children are
travelling in the car . . . . . . . . . . . . .
Child safety seats . . . . . . . . . . . . . .
Fitting child safety seats . . . . . . . .
Driving tips
. . . . . . . . . . . . . . . .
Intelligent technology
. . . . . . . . . .
Electronic stabilisation program
(ESP) . . . . . . . . . . . . . . . . . . . . . . . . . .
Brakes . . . . . . . . . . . . . . . . . . . . . . . . .
Power steering (servotronic) . . . . .
Four-wheel drive (quattro®) . . . . . .
Power management . . . . . . . . . . . .
Your vehicle and the
environment
. . . . . . . . . . . . . . . . . . .
Running in . . . . . . . . . . . . . . . . . . . . .
Emission control systems . . . . . . .
How to improve economy and
minimise pollution . . . . . . . . . . . . . .
Environmental compatibility . . . . .
Towing a trailer
. . . . . . . . . . . . . . . .
Driving the vehicle with a trailer or
caravan . . . . . . . . . . . . . . . . . . . . . . .
Removable towing bracket . . . . . .
General maintenance
. . .
Care of vehicle and cleaning
. . .
General notes . . . . . . . . . . . . . . . . . .
Care of exterior . . . . . . . . . . . . . . . . .
Care of interior . . . . . . . . . . . . . . . . .
Fuel and filling the tank
. . . . . . . .
Petrol . . . . . . . . . . . . . . . . . . . . . . . . . .
Diesel . . . . . . . . . . . . . . . . . . . . . . . . .
Filling the tank . . . . . . . . . . . . . . . . . .
Checking and topping up fluidsBonnet . . . . . . . . . . . . . . . . . . . . . . . .
Engine compartment layout . . . . . .
Engine oil . . . . . . . . . . . . . . . . . . . . . .
Cooling system . . . . . . . . . . . . . . . . .
Brake fluid . . . . . . . . . . . . . . . . . . . . .
Battery . . . . . . . . . . . . . . . . . . . . . . . .
Windscreen washer . . . . . . . . . . . . .Wheels and tyres
. . . . . . . . . . . . . . .
Wheels . . . . . . . . . . . . . . . . . . . . . . . .
Run flat tyres . . . . . . . . . . . . . . . . . . .
Accessories and modifications
to the vehicle
. . . . . . . . . . . . . . . . . . .
Accessories and replacement
parts . . . . . . . . . . . . . . . . . . . . . . . . . .
Modifications . . . . . . . . . . . . . . . . . .
Radio transmitters and business
equipment . . . . . . . . . . . . . . . . . . . . . 185
186
186
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222
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Lights and vision61
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Applies to vehicles: with xenon headlight bulbsDynamic headlight range controlHeadlights with xenon gas-discharge bulbs automatically adapt to
suit the load being carried when the engine is switched on. The
headlights are also automatically adjusted when the vehicle is in
motion (e.g. when accelerating and braking).Applies to vehicles: with adaptive lightadaptive light
This feature provides better illumination when you drive
through a corner.The adaptive light gives better illumination of the bend and the side
of the road when driving through a corner ⇒fig. 59. The adaptive
light is controlled automatically, depending on the speed of the
vehicle and the steering wheel angle.
The headlights are regulated automatically when you drive through
a corner, depending on how far you turn the steering wheel. To
avoid having a dark spot in front of the vehicle the two headlights
are directed at different angles.
Note
The system is active at speeds from approximately 10 km/h to
110 km/h.Hazard warning lights

The hazard warning lights are used to make other road
users aware of your vehicle in hazardous situations.– Press the switch
 to switch the hazard warning lights
on or off ⇒fig. 60.
All four turn signals flash simultaneously when the hazard warning
lights are switched on. The two turn signal indicator lamps
  and
the indicator lamp in the switch
 will flash at the same time. The
hazard warning lights also work when the ignition is switched off.
The hazard warning lights come on automatically in the event of an
accident in which an airbag is triggered or in the case of an emer-
gency stop (full brake application).
Note
You should switch on the hazard warning lights to warn other road
users, for instance:
Fig. 59 adaptive light
when driving
Fig. 60 Switch for
hazard warning lights
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Driving123
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data braking force of the parking brake is only released when there is
enough power at the wheels to make the vehicle move in the desired
direction.
Note
For safety reasons the parking brake will only release automatically
if the driver's seat belt is engaged in its buckle.Driving away when towing a trailer
Please note the following points to prevent the vehicle
from rolling back unintentionally on a gradient.– Pull and hold the parking brake switch and press the
accelerator. The parking brake will remain engaged and
prevent any tendency to roll back down the slope.
– You can release the parking brake switch as soon as the
engine is delivering enough power to the wheels.Depending on the weight of the vehicle and trailer and the steep-
ness of the slope, there may be a tendency to roll back downhill
when driving away from a standstill. You can prevent this by pulling
out the parking brake switch as you press the accelerator (in the
same way as with a conventional handbrake).Emergency braking function
This feature enables you to stop the vehicle if the main
brake system should fail or if the pedal is obstructed.– Pull out and hold the parking brake switch to stop the
vehicle with the parking brake in an emergency.
– The brakes will be released immediately if you release the
switch or press down the accelerator.
If you pull out and hold the parking brake switch at a road speed
above about 8 km/h, this will initiate an emergency brake applica-
tion. The brakes are then applied hydraulically at all four wheels.
The effect is the same as an emergency stop (full brake application)
⇒
To prevent the emergency braking function from being used acci-
dentally, a warning buzzer sounds when the switch is operated. The
brakes are released immediately when you release the switch or
press down the accelerator.
WARNING
You should only use the emergency braking function in a real
emergency, for example if the brake system should fail or if the
brake pedal is obstructed. If you use the emergency braking func-
tion by activating the parking brake switch, the effect is similar to
a full brake application (emergency stop). Please remember that
the ESP (with its combined ABS, EDL and traction control func-
tions) is still subject to certain physical limits. In a corner or in bad
road or weather conditions an emergency stop can cause the
vehicle to skid or lose steering control.Driver messages in the instrument cluster displayCaution: Vehicle parked too steep
This message can appear when you apply the parking brake if the
car is parked on a gradient steeper than about 30%.
In this case the parking brake may not be strong enough to prevent
the vehicle from rolling back accidentally.
Please release parking brake
However, please remember that, for safety reasons, the parking
brake will only release automatically if the driver's seat belt is
buckled.
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Seat belts 196The physical principles involved in a frontal collision are relatively
simple:
Both the moving vehicle and the passengers possess energy, which
is known as “kinetic energy” ⇒page 195, fig. 204. The amount of
“kinetic energy” depends on the speed of the vehicle and the weight
of the vehicle and passengers. The higher the speed and the greater
the weight, the more energy there is to be absorbed in an accident.
The most significant factor, however, is the speed of the vehicle. If
the speed doubles from 25 km/h to 50 km/h, for example, the kinetic
energy increases by a factor of four. Because these passengers are
not restrained by seat belts, the entire amount of kinetic energy has
to be absorbed at the point of impact ⇒fig. 205. This would result
in serious or potentially fatal injury.
Even at urban speeds of 30 km/h to 50 km/h, the forces acting on the
occupants in a collision can reach the equivalent of 1 ton (1000 kg)
or more. At greater speed these forces are even higher. A rule of
thumb: if the speed doubles, the forces increase by a factor of four.
Passengers who do not wear seat belts are not “attached” to the
vehicle. In a frontal collision they will continue to move forward at
the speed their car was travelling just before the impact.
What happens to passengers not wearing seat belts?
Passengers not wearing seat belts risk fatal injuries in the
event of an accident.In a frontal collision, unbelted passengers will be thrown forwards
and make violent contact with the steering wheel, dashboard, wind-
screen, etc ⇒fig. 206. Passengers not wearing their belts risk being
thrown out of the car, resulting in potentially fatal injuries.
The common belief that occupants can brace their weight with their
hands in a minor collision is false. Even at low speeds the forces
acting on the body in a collision are so great that it is not possible
to hold yourself in the seat.
Fig. 205 The vehicle
crashes against the
wall
Fig. 206 A driver not
wearing a seat belt can
be thrown forwardsFig. 207 A rear
passenger not wearing
a seat belt can be
thrown forwards
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Intelligent technology 222Intelligent technologyElectronic stabilisation program (ESP)DescriptionESP increases the car's stability. It reduces the tendency to skid and
improves the stability and roadholding of the vehicle. ESP detects
critical handling situations, such as understeer, oversteer and
wheelspin on the driven wheels. It stabilises the vehicle by braking
individual wheels or by reducing the engine torque. The warning
lamp
 in the instrument cluster starts flashing as soon as the ESP
intervenes.
The ESP incorporates the functions of the anti-lock brake system
(ABS), the traction control system (ASR), the electronic differential
lock (EDL) and the dynamic steering*.
Anti-lock brake system (ABS)
ABS prevents the wheels from locking up under braking until the
vehicle has reached a virtual standstill. You can continue to steer the
vehicle even when the brakes are on full. Keep your foot on the brake
pedal and do not pump the brakes. You will feel the brake pedal
pulsate while the anti-lock brake system is working.
Brake assist system
The brake assist system can speed up the braking process and
shorten the braking distance. It automatically boosts the braking
force if you press the brake pedal quickly in an emergency. On vehi-
cles with adaptive cruise control*, the brake assist system will build
up a small amount of pressure in the hydraulic brake system if it
senses that you are too close to the vehicle in front.
Traction control system (ASR)
In the event of wheelspin, the traction control system reduces the
engine torque to match the amount of grip available. This helps the
car to start moving, accelerate or climb a gradient.Electronic differential lock (EDL)
When the EDL detects wheelspin, it brakes the spinning wheel and
directs the power to the other driven wheel (or wheels on quattro*
versions). This function is active up to about 100 km/h.
To prevent the disc brake of the braked wheel from overheating, the
EDL cuts out automatically if subjected to excessive loads. The
vehicle can still be driven. The EDL will switch on again automati-
cally when the brake has cooled down.
Dynamic steering*
On vehicles with dynamic steering*, the ESP can also intervene in
the steering to stabilise the vehicle in critical situations.
WARNING
•
The grip provided by the ESP, ABS, ASR, EDL and dynamic
steering* systems is still subject to the physical limits of adhesion.
Always bear this in mind, especially on wet or slippery roads. If
you notice the systems cutting in, you should reduce your speed
immediately to suit the road and traffic conditions. Do not let the
extra safety provided tempt you into taking any risks when driving
– this can cause accidents.
•
Please remember that the accident risk always increases if you
drive fast, especially in corners or on a slippery road, or if you
follow too close behind the vehicle in front of you. Please bear in
mind that even ESP, ABS, brake assist, EDL, ASR and dynamic
steering* cannot compensate for the increased accident risk.
•
When accelerating on a uniformly slippery surface (for instance
all four wheels on ice or snow), press the accelerator gradually and
carefully. The driven wheels may otherwise start to spin (in spite
of the integrated control systems), which would impair the car's
stability and could lead to an accident.
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Intelligent technology223
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Note
•
To ensure that the ASR works properly, all four wheels must be
fitted with identical tyres. Any differences in the rolling radius of the
tyres can cause the system to reduce engine power when this is not
desired.
•
Should a malfunction occur in the ABS or EDL, both the ABS
warning lamp
 and the ESP warning lamp
 ⇒page 19 will light
up.
•
In the event of a malfunction in the ESP system, the warning
lamp  ⇒page 17 will light up.
•
If a malfunction should occur in the ABS, the ESP, EDL and ASR
will also be out of action.
•
The systems can make noises when they intervene.
Switching on and off
The ESP is switched on automatically when the engine is
started.
Switching off the traction control system (ASR)
In particular circumstances, it may be advisable to switch off the
traction control system (ASR) to allow a certain amount of wheel
slip. For example:•
Rocking the car backwards and forwards to free it
•
Driving in deep snow or on loose surfaces
•
Driving with snow chains
Press the button briefly ⇒fig. 232 or ⇒fig. 233. The
warning lamp
 will light up and the message ASR off will appear
in the driver information system display.
The traction control system (ASR) can only be switched off at speeds
below 50 km/h on vehicles with front-wheel drive. At 70 km/h it will
switch on again automatically. The ASR can be deactivated at any
speed on vehicles with four-wheel drive.
Switching off the ESP
Press the button for longer than 3 seconds. The ESP
warning lamp  will light up and the message ESP switched off will
appear in the display. The ASR is also deactivated when the ESP is
switched off.
Switching on
Press the button again. The message ESP/ASR on will
appear briefly on the display.
Fig. 232 Version A:
Centre console
(bottom), ESP OFF
button
Fig. 233 Version B:
Centre console (top),
ESP OFF button
ESP OFFESP OFFESP OFF
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Intelligent technology 226Applies to vehicles: with four-wheel driveFour-wheel drive (quattro
®)
On quattro models the engine power is distributed to all
four wheelsGeneral notes
On four-wheel drive vehicles, the engine power is distributed to all
four wheels. The distribution of power is controlled automatically
according to your driving style and the road conditions. Also refer
to ⇒page 222, “Description”.
The four-wheel drive is specially designed to complement the supe-
rior engine power of your Audi. This combination gives the car
exceptional handling and performance capabilities – both on
normal roads and in more difficult conditions, such as snow and ice.
Even so (or perhaps especially for this reason), it is important to
observe certain safety points ⇒.
Winter tyres
Thanks to its four-wheel drive, your car will have plenty of traction
in winter conditions, even with the standard tyres. Nevertheless, we
still recommend that winter tyres or all-season tyres should be fitted
on all four wheels when winter road conditions are expected, mainly
because this will give a better braking response.
Snow chains
On roads where snow chains are mandatory, this also applies to cars
with four-wheel drive ⇒page 273, “Snow chains”.
Replacing tyres
On vehicles with four-wheel drive, all four tyres must have the same
rolling circumference. Also avoid using tyres with varying tread
depths ⇒page 270, “Replacing wheels and tyres”.Off-roader?
Your Audi does not have enough ground clearance to be used as an
off-road vehicle. It is therefore best to avoid rough tracks and
uneven terrain as much as possible.
WARNING
•
Even with four-wheel drive, you should always adjust your
speed to suit the conditions. Do not let the extra safety provided
tempt you into taking any risks when driving – this can cause acci-
dents.
•
The braking ability of your car is limited by the grip of the tyres.
In this respect, your car is no different from a car without four-
wheel drive. So do not be tempted to drive too fast on icy or slip-
pery roads just because the car still has good acceleration in these
conditions (accident risk).
•
On wet roads bear in mind that the front wheels may start to
“aquaplane” and lose contact with the road if the car is driven too
fast. If this should happen, there will be no sudden increase in
engine speed to warn the driver, as with a front-wheel drive car. So
do not drive too fast in the wet: adjust your speed to suit the
conditions (accident risk).
Power managementThis system helps to ensure reliable starting
The power management controls the distribution of elec-
trical energy and thus helps to ensure that there is always
enough power available to start the engine.If a vehicle with a conventional electrical system is left parked for a
long time, the battery will gradually lose its charge because certain
electrical equipment (such as the immobiliser) continues to draw
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Wheels and tyres271
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
– Never use tyres whose actual size exceeds the dimen-
sions of the factory-approved makes of tyre.
– If you wish to fit the vehicle with non-standard rims or
tyres, it is advisable to consult an Audi dealer before
purchasing them.The tyres and wheel rims are an essential part of the vehicle's
design. The tyres and rims approved by Audi are specially matched
to the characteristics of the vehicle and make a major contribution
to good roadholding and safe handling ⇒.
The sizes of the rims and tyres approved for your vehicle are listed
in the vehicle's documents (e.g. EC Certificate of Conformity or COC
document
3)). The vehicle documents vary depending on the
country of residence.
Understanding the tyre designations makes it easier to choose the
correct tyres. For example, radial ply tyres have the following tyre
designations marked on the sidewall:
225 / 50 R 17 94 Y
This contains the following information:
The manufacturing date is also indicated on the tyre sidewall
(possibly only on the inner side of the wheel):
DOT ... 1006...means, for example, that the tyre was produced in the 10th week of
2006.
Please note that with some types of tyres, the actual tyre size can
differ from the nominal size marked on the tyre (for instance 225/50
R 17 94 Y), and there may be significant differences in the contours
of the tyres, even though the tyres are marked with the same
nominal size designation. When replacing the tyres, it is therefore
important to make sure that the actual size of the new tyres does
not exceed the dimensions of the factory-approved makes of tyre.
Failure to observe this requirement can affect the clearance needed
for the tyres. This could result in contact between the tyres and
suspension components or bodywork. The brake lines could also be
damaged and the vehicle's safety could be severely impaired ⇒.
When using tyres with the maximum permitted nominal dimen-
sions, this can also void the vehicle's registration.
If you use tyres that are approved by Audi you can be sure that the
actual tyre dimensions will be correct for your vehicle. If you decide
to fit a different type of tyre, you must obtain the appropriate manu-
facturer's certificate from the tyre retailer to confirm that the tyres
are suitable for your vehicle. Keep this certificate in a safe place.
Your local Audi dealer will be able to advise you on which tyres may
be fitted to your vehicle.
On vehicles with four-wheel drive, all four tyres must always be
fitted with tyres of the same type, make and tread pattern, as other-
wise the driveline can be damaged by continuous variations in the
wheel speeds. For the same reason, only use a spare wheel* with
the same tyre dimensions as the normal road wheels.
It the spare tyre* is not the same type as the tyres fitted on the car
(for example if the car has winter tyres or wide-section tyres) you
should only use the spare tyre if a puncture occurs, and then only
for a short period of time. In this case, please drive with extra care.
Refit the normal road wheel as soon as possible.
It is best to have all servicing of wheels and tyres performed by a
qualified workshop. They have the necessary special tools and
3)COC = certificate of conformity
225
Tyre width in mm
50
Height/width ratio in %
R
Tyre construction: Radial
17
Rim diameter in inches
94
Load rating code
Y
Speed rating code letter
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