AUDI S5 2008 8T / 1.G Owners Manual
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Technical data can cause the system to reduce engine power when this is not
desired. Also refer to ⇒page 234, “Replacing wheels and tyres”.
Electronic differential lock (EDL)
The electronic differential lock monitors the speed of the
driven wheels.General notes
The electronic differential lock (EDL) helps the car to start moving,
accelerate and climb a gradient in slippery conditions where this
may otherwise be difficult or even impossible.
How the system works
The EDL acts automatically. With the aid of the ABS sensors
⇒page 187, the system monitors the rotational speed of the driven
wheels on each axle. Whenever it detects a significant difference in
the speed of the driven wheels of one axle (for example, if the road is
slippery on one side) the system applies the brake to slow down the
spinning wheel so that more of the power is directed to the other
wheels. This function is active up to about 100 km/h. The brake
system will make noises while it is working.
Driving away from a standstill
Sometimes one wheel has less grip and starts spinning, for
example, if one of the driven wheels is on ice. In this case, keep
pressing the accelerator gradually until the car starts moving, even
though the wheel with less grip will still spin.
Overheating of the brakes
To prevent the disc brake of the braked wheel from overheating, the
EDL cuts out automatically if subjected to excessive loads. The car
remains operational and will behave in the same way as a car
The EDL will switch on again automatically when the brake has
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 EDL), which would impair the car's stability and could lead
to an accident.
Even with EDL, 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 accidents.Note
If the ABS warning lamp lights up, this can also mean there is a fault
in the EDL. Please contact a qualified workshop as soon as
possible.BrakesNew brake pads
New brake pads do not give full braking effect for the first 400 km,
they must first be “bedded in”. However, you can compensate for
the slightly reduced braking effect by applying more pressure on
the brake pedal. Avoid placing a heavy load on the brakes during the
The rate of wear on the brake pads depends a great deal on how you
drive and the conditions in which the vehicle is operated. Negative
factors are, for instance, city traffic, frequent short trips or hard
driving with abrupt starts and stops.
Wet roads; road salt
When you are driving at a speed higher than 80 km/h and have the
windscreen wipers switched on the brake pads are very briefly
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which goes unnoticed by the driver is carried out at regular intervals
and is intended to improve braking response in wet conditions.
In certain conditions, such as in heavy rain, or after washing the car
or driving through water, the full braking effect can be delayed by
moisture (or in winter by ice) on the discs and brake pads. The
brakes should be “dried” by pressing the pedal to restore full
The effectiveness of the brakes can also be temporarily reduced if
the car is driven for some distance without using the brakes when
there is a lot of salt on the road in winter. The layer of salt that accu-
mulates on the discs and pads can be removed with a few cautious
There may be a tendency for dirt to build up on the brake pads and
corrosion to form on the discs if the car is used infrequently, or if
you only drive low mileages without using the brakes very much.
If the brakes are not used frequently, or if corrosion has formed on
the discs, it is advisable to clean off the pads and discs by braking
firmly a few times from a moderately high speed ⇒.
Faults in the brake system
If the brake pedal travel should ever increase suddenly, this may
mean that one of the two brake circuits has failed. Drive immedi-
ately to the nearest qualified workshop and have the fault rectified.
On the way to the dealer, be prepared to use more pressure on the
brake pedal and allow for longer stopping distances.
Low brake fluid level
Malfunctions can occur in the brake system if the brake fluid level is
too low. The brake fluid level is monitored electronically.
The brake servo amplifies the pressure you apply to the brake pedal.
It only works when the engine is running.
When applying the brakes to clean off deposits on the pads and
discs, select a clear, dry road. Be sure not to inconvenience or
endanger other road users; do not risk an accident.
Never let the car coast with the engine switched off (this can
Never let the brakes “drag” by leaving your foot on the pedal
when you do not really intend to brake. This overheats the brakes,
resulting in longer stopping distances and greater wear.
Before driving down a long, steep gradient, it is advisable to
reduce speed and move the selector lever to a lower gear. In this
way you will make use of the engine braking effect and relieve the
load on the brakes. If you still have to use the brakes, it is better to
brake firmly at intervals than to apply the brakes continuously.Note
If the brake servo is out of action due to a malfunction, or if the
car has to be towed, you will have to press the brake pedal consid-
erably harder to make up for the lack of servo assistance.
If you wish to equip the car with accessories such as a front
spoiler or wheel covers, it is important that the flow of air to the
front wheels is not obstructed, otherwise the brakes can overheat.
Power steering (servotronic)The power steering assists the driver when turning the
steering wheel (with the engine running).The power steering assists the driver by reducing the force needed
to turn the steering wheel. The degree of power assistance is
adapted electronically, depending on the speed.
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Technical data If a fault should occur in the servotronic system the power steering
will still operate. The degree of power assistance will, however, no
longer adapt to different speeds. If the electronic regulating system
is not working properly, this is most noticeable when turning the
steering wheel at low speeds (for instance when parking) – more
effort will be required than usual. The fault should be corrected by
a qualified workshop as soon as possible.
The power steering does not function when the engine is switched
off. In this case the steering wheel is very hard to turn.
If the steering is held at its turning limit when the car is stationary,
this will place an excessive load on the power steering system. In
this case, the power steering system will make noises. It will also
reduce the idling speed of the engine.
Do not keep the steering in the full-lock position for longer than
15 seconds when the engine is running – this could cause damage
to the power steering system.
If the power steering should fail at any time or the engine is
switched off (for instance when being towed), the car can still be
steered. However, more effort will be required to turn the steering
If the system is leaking or malfunctioning, please take the car to
a qualified workshop as soon as possible.
The power steering requires a special hydraulic fluid. The fluid
reservoir is located at the front of the engine compartment on the
left ⇒page 222. The correct fluid level in the reservoir is important
for the power steering to function properly. The hydraulic fluid level
is checked at the Inspection Service.
Four-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 189, “Electronic differential lock (EDL)”.
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 ⇒.
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.
On roads where snow chains are mandatory, this also applies to cars
with four-wheel drive ⇒page 237, “Snow chains”.
On vehicles with four-wheel drive, all four tyres must have the same
rolling circumference. Also avoid using tyres with varying tread
depths ⇒page 234, “Replacing wheels and tyres”.
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.
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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-
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
current even when the ignition is off. In some cases there may not
be enough power available to start the engine.
Your vehicle is equipped with an intelligent power management
system to control the distribution of electrical energy. This signifi-
cantly improves reliability when starting the engine, and also
prolongs the life of the battery.The main functions incorporated in the power management system
are battery diagnosis, residual current management and dynamic
The battery diagnosis function constantly registers the condition of
the battery. Sensors detect the battery voltage, battery current and
battery temperature. This enables the system to calculate the
current power level and charge condition of the battery.
Residual current management
The residual current management reduces power consumption
while the vehicle is parked. It controls the supply of power to the
various electrical components while the ignition is switched off. The
system takes the battery diagnosis data into consideration.
Depending on the power level of the battery, the individual electrical
components are switched off one after the other to prevent the
battery from losing too much charge and to ensure that the engine
can be started reliably.
Dynamic power management
While the vehicle is moving, this function distributes the available
power to the various electrical components and systems according
to their requirements. The power management ensures that on-
board systems do not consume more electrical power than the
alternator can supply, and thus maintains the maximum possible
battery power level.
The power management system is not able to overcome the
given physical limits. Please remember that the power and life of
the battery are limited.
A warning message will appear ⇒page 193, “Driver message in
the instrument cluster display” if the battery power has dropped to
a level where reliable starting is impaired.
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Points to remember
Starting ability has first priority.Short trips, city traffic and low temperatures all place a heavy load
on the battery. In these conditions a large amount of power is
consumed, but only a small amount is supplied. The situation is also
critical if electrical equipment is in use when the engine is not
running. In this case power is consumed when none is being gener-
In these situations you will be aware that the power management
system is intervening to control the distribution of electrical power.
When the vehicle is parked for long periods
If you do not drive your vehicle for a period of several days or weeks,
the power management will gradually shut off the on-board
systems one by one, or reduce the amount of current they are using.
This limits the amount of power consumed and helps to ensure reli-
able starting even after a long period.
Please note that certain convenience features, such as the Audi
advanced key*, the remote control key or the electrical seat adjust-
ment may not be available when you unlock the vehicle. These func-
tions will be restored when you switch on the ignition and start the
With the engine switched off
If you listen to the radio or use the other MMI functions when the
engine is not running, this will discharge the battery.
The MMI display will show this warning message before the battery
power drops to a level where the starting ability is impaired.
Please start engine, otherwise system will switch off
in 3 minutes.
This message warns you that the system you are using will be
switched off automatically after 3 minutes. You should therefore
start the engine if you wish to continue using the system.When the engine is running
Although the alternator generates electrical power, the battery can
still become discharged while the vehicle is being driven. This can
occur when a lot of power is being consumed but only a small
amount supplied, especially if the battery is not fully charged
To restore the necessary energy balance, the system will then
temporarily shut off the electrical components that are using a lot
of power, or reduce the current they are consuming. Heating
systems in particular use a large amount of electrical power. If you
notice, for instance, that the seat heating* or the rear window
heater is not working, they may have been temporarily switched off
or regulated to a lower heat output. These systems will be available
again as soon as sufficient electrical power is available.
You may also notice that the engine runs at a slightly faster idling
speed. This is quite normal, and no cause for concern. The increased
idling speed allows the alternator to meet the greater power
requirement and charge the battery at the same time.
Driver message in the instrument cluster displayIf battery power drops to a level at which you may encounter prob-
lems when starting the engine, the following message will appear
in the instrument cluster display:
Low battery charge: Battery will be charged while driving
This message reminds you that the starting reliability may be
impaired. The message will disappear as soon as you set off and the
battery is charged.
Message comes on and goes out again
If the message appears in the display after the ignition is switched
on or while driving, and goes out again after a period of time, the
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Message comes on and does not go out
If the message appears in the display after the ignition is switched
on or while driving, and does not go out again, the battery is not
being maintained at the proper power level. Starting reliability may
be impaired. You should have the battery checked by a qualified
workshop as soon as possible.
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Downloaded from www.Manualslib.com manuals search engine Your vehicle and the environment195
Your vehicle and the environmentRunning inA new vehicle should be run in over a distance of 1,500 km. For the
first 1,000 km the engine speed should not exceed 2/3 of the
maximum permissible engine speed – do not use full throttle and do
not tow a trailer or caravan. From 1,000 to 1,500 km you can gradu-
ally increase the engine rpm and road speed.
During its first few hours of running, the internal friction in the
engine is greater than later on when all the moving parts have
How the vehicle is driven for the first 1,500 km also influences the
engine quality. After the first 1,500 km you should continue driving
at moderate engine speeds, in particular when the engine is cold.
This helps to reduce wear and tear on the engine and increases the
potential mileage which can be covered by the engine.
You should also avoid driving with the engine speed too low.
Change down to a lower gear when the engine no longer runs
“smoothly”. Excessively high engine speeds are prevented by an
automatic rev limiter.Catalytic converterThe vehicle must only be used with unleaded petrol, otherwise the
catalytic converter will be destroyed.
Never run the tank completely dry. The irregular fuel supply can
cause misfiring, which would allow unburnt fuel to enter the
exhaust system, which could cause overheating and damage the
Because of the high temperatures which can occur in the cata-
lytic converter, do not park the vehicle where the catalytic
converter can come into contact with flammable materials under
the car (e.g. on grass or at the forest edge). - Fire hazard!
Do not apply any underseal agents in the area around the
exhaust system - fire hazard!
Driving abroadChanging over headlight dip settings
The asymmetric low beams of the headlights are designed to light
up the near side of the road more intensely. If you drive in a country
where traffic drives on the opposite side of the road to the home
country, this will dazzle oncoming traffic. The headlight dip settings
must be changed to avoid dazzling oncoming traffic. For safety
reasons, the dip settings may only be changed by a qualified work-
For further information, please consult an Audi dealer or other qual-
A car with catalytic converter must not be run with leaded petrol
⇒page 195. Before driving abroad make sure that unleaded petrol
is available there.
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Downloaded from www.Manualslib.com manuals search engine Your vehicle and the environment 196How to improve economy and minimise pollutionFuel economy, environmental impact and wear on the engine,
brakes and tyres depend largely on the way you drive the vehicle. By
adopting an economical driving style and anticipating the traffic
situation ahead, you can reduce fuel consumption by 10-15%. The
following section gives you some tips on lessening the impact on
the environment and reducing your operating costs at the same
Anticipate well in advance
A car uses most fuel when accelerating. If you anticipate hazards
and speed changes well in advance, you will need to brake less and
thus accelerate less. Wherever possible, let the car slow down grad-
ually with a gear engaged, for instance when you can see that the
next traffic lights are red. This takes advantage of the engine
braking effect, reducing wear on the brakes and tyres. Emissions
and fuel consumption will drop to zero due to the overrun fuel cut-
Change gear early to save fuel
An effective way of saving fuel is to change up quickly through the
gears. Running the engine at high rpm in the lower gears uses an
unnecessary amount of fuel.
Manual gearbox: Shift up to second gear as soon as possible. If
possible, we recommend shifting up to the next gear at approx.
Automatic gearbox: Press the accelerator slowly and avoid using
the “kick-down” feature.
Avoid driving at high speed
Avoid travelling at top speed. Fuel consumption, exhaust emissions
and noise levels all increase very rapidly at higher speeds. Driving at
moderate speeds will help to save fuel.Do not let the engine idle for longer than necessary
It is worthwhile switching off the engine when waiting in a traffic
jam, at level crossings or at traffic lights with a long red phase. The
fuel saved after only 30 - 40 seconds is greater than the amount of
fuel needed to restart the engine.
The engine takes a very long time to warm up when it is running at
idling speed. Mechanical wear and pollutant emissions are also
especially high during this initial warm-up phase. It is therefore best
to drive off immediately after starting the engine. Avoid running the
engine at high speed.
Regular servicing can establish a basis for good fuel economy
before you start driving. A well-serviced engine gives you the
benefit of improved fuel efficiency as well as maximum reliability
and an enhanced resale value. A badly tuned engine can consume
up to ten percent more fuel than necessary.
Avoid short trips
The engine and emission control system need to reach their proper
working temperature in order to minimise fuel consumption and
A cold engine uses disproportionately more fuel. The engine only
reaches its working temperature after about four kilometres, when
fuel consumption will return to a normal level. This is the reason
why we recommend avoiding short trips wherever possible.
Maintain the correct tyre pressures
Always make sure the tyres are inflated to the correct pressures
⇒page 232 to save fuel. If the tyre pressures are just 0.5 bar too low,
this can increase the fuel consumption by as much as 5 %. Due to
the greater rolling resistance, under-inflation also increases tyre
wear and impairs handling.
Do not use winter tyres all through the year; they will increase fuel
consumption by up to 10 %.
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Technical data Avoid carrying unneccessary loads
Every kilo of extra weight will increase the fuel consumption, so it is
worth checking the luggage compartment occasionally to make
sure that no unnecessary loads are being transported.
A roof carrier is often left in place for the sake of convenience, even
when it is no longer needed. At a speed of 100-120 km/h your car will
use about 12 % more fuel as a result of the extra wind resistance
caused by the roof carrier - even when it is empty.
Save electrical energy
The engine drives the alternator to generate electricity. This means
that fuel consumption rises when more power is required for elec-
trical equipment. Switch off electrical equipment when it is not
needed. Electrical equipment which uses a lot of electricity includes
the blower (at a high setting), the rear window heating and the seat
Environmental compatibilityEnvironmental protection is a top priority in the design, choice of
materials and production of your new Audi.
Design measures for economical recycling•
Joints and connections designed for ease of dismantling
Modular construction to facilitate dismantling
Increased use of single-grade materials
Plastic parts and elastomers are labelled in accordance with ISO
1043, ISO 11469 and ISO 1629
Choice of materials
Nearly all materials used can be recycled
Similar types of plastics grouped together for easy recycling
Recycled materials used in manufacture
Reduced vapour emissions from plastics
CFC-free refrigerant in air conditioner
Compliance with the laws prohibiting the use of: Cadmium,
asbestos, lead, mercury and chrome VI.
Using recycling material for manufacturing plastic parts
Solvent-free cavity sealing
Solvent-free wax for protecting the vehicles in transit
No CFCs used in production
Surplus materials used extensively for energy conversion and
Overall water consumption reduced
Heat recovery systems
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Downloaded from www.Manualslib.com manuals search engine Towing a trailer 198Towing a trailerDriving the vehicle with a trailer or
The towing bracket must comply with certain technical
requirements.Your car is intended mainly for transporting passengers and
luggage. However, if suitably equipped, it can also be used to tow a
trailer or caravan.
If the car is supplied with a factory-fitted towing bracket it will
already have the necessary technical modifications and meet the
A 13-pin socket is provided to make the electrical connection
between the car and the trailer. If the trailer has a 7-pin plug you can
use an adapter cable. This is available from Audi dealers.
If a towing bracket is retrofitted, the installation should be carried
out by a qualified workshop.•
In particular in high outside temperatures it is not possible to
drive up long steep gradients without a suitable cooling system.
The engine would then overheat.
Incorrect installation can result in a safety risk.
Points to check before towingTrailer weights
Never exceed the maximum permitted trailer weights ⇒page 281.If you do not load the trailer up to the maximum permitted trailer
weight, you can then climb correspondingly steeper gradients.
The maximum trailer weights listed are only applicable for altitudes
up to 1000 m above sea level. With increasing altitude the engine
power and therefore the car's climbing ability are impaired because
of the reduced air density, so the maximum trailer weight has to be
reduced accordingly. The weight of the car and trailer must be
reduced by 10% for every further 1000 m (or part thereof). This
figure refers to the combined weight of the (loaded) vehicle and
The figures for the draw bar weight that appear on the identification
plate of the towing bracket are for certification purposes only. The
correct figures for your specific vehicle, which may be lower than
these figures for the towing bracket, are given in the registration
documents. Also refer to ⇒page 281.
Distributing the load
Distribute loads in the trailer so that heavy objects are as near to the
axle as possible. Loads carried in the trailer must be secured to
prevent them slipping.
Where possible, operate the trailer with the maximum permitted
draw bar weight on the ball joint of the towing bracket, but do not
exceed the specified limit.
Check the tyre pressures on your car and adjust for “full load” condi-
tions (refer to the sticker listing the tyre pressures on the end face
of the driver's door). It may also be necessary to adjust the tyre pres-
sures on the trailer according to the recommendations of the trailer
Check whether you can see enough of the road behind the trailer
with the standard mirrors. If this is not the case you should have
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