2009 AUDI S8 fuel pressure

Operating instructions
Max im um tra iler weight
A trailer for your vehicle is limited to a typical class 1 or class 2
trailer.
T ra ile r l oa d di stributio n
Be sure the load in the trailer is he ld securely in place to prevent it
from shifting forward, backward or sideways .
Never allo w a passe nger to r ide in a tr aile r~ & in "Driving instruc­
tions" .
Engin e c oolin g sys te m
Towing a trailer makes the eng ine work harder. It is important that
the cooling system's performance is up to the additiona l load. Make
sure that the coo ling system has enough fluid .
Tire pr ess ure
When towing a trailer, inflate the tires of your vehicle to the co ld tire
pressure listed under "Full load" on the labe l located either on the
driver's side B -pil lar (visible when the door is open) or inside the fuel
filler flap . Inflate trai ler tires to trai ler and tire manufacturers' spec­
ifications.
L ig ht s
The head light settings should be checked wit h the trai ler attached
before driving off. Check to make sure both vehicle and trai ler lights
are working properly .
Safe ty c ha in s
Be sure traile r safety chains are properly connected from the trailer
to the hitch on the vehicle. Leave enough slack in the chains to
perm it turning corners . When you i nsta ll safety chains, make sure
they will not drag on the road when you are driving.
T he chains should cross under the trailer tongue to prevent it from
dropping in case of separat ion from the hitch.
Controls and equip­
ment Safety first Vehicle operation
Tr
aile r t owing
0 Note
If you are going to tow a trai ler, you must activate the trailer opera­
tion mode ~
page 192, "Towing a Trailer". •
Driving instructions
Driving with a trailer always requires extra care and
consideration.
To obtain the best possible handling of veh icle and trailer,
please note t he following :
- Do not tow a loaded trailer when your car itself is not
loaded.
Be espec ia lly careful whe n passing other vehicles.
- Observe s peed limits .
Do not drive at the maximum permiss ible speed .
Always apply brakes ear ly.
Moni tor t he temperature ga uge.
Weight distr ibution
Towing a loaded trailer with an empty car results in a highly
unstable distr ibution of weight. If this cannot be avoided, drive at
very low speeds only to avoid the risk of losing steering control.
A "balanced" rig is easier to operate and control. This means that
the tow vehicle should be loaded to the extent possible and perm is ­
s ib le, while keeping the trailer as light as possib le under the circum ­
stances . Whenever possible, transfe r so me cargo to t he luggage
compartment of the tow vehicle whi le observing tongue load
requirements and vehicle loading considera tions . .,
Vehicle care Do-it-yourself service Technical data

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•
Closing the engine hood
- Pull the hood down until the pressure from the struts is
reduced .
- Let the hood
drop down and latch in place. Do not try to
push it shut;
it may fail to engage => &.
& WARNING
A hood that is not completely latched could fly up and block your
view while driving.
• When you close the engine hood, check it to make sure the
safety catch has properly engaged. The hood should be flush with
the surrounding vehicle body parts.
• If you notice while driving that the hood is not secured prop­
erly, stop at once and close it. •
Working in the engine compartment
Be especially careful whenever you work in the engine
compartment.
Whenever you must perform any work in the engine compartment,
for example checking and filling different fluids, there is a risk of injury, burns and accidents. To prevent personal injury always
observe the following WARNINGS. The engine compartment of any
vehicle is a hazardous area
~ & .
& WARNING
To help avoid injury, before you check anything under the hood :
• Turn off the engine.
• Remove the ignition key.
• Apply the parking brake .
& WARNING (continued)
• Move selector lever to "P" (Park).
• Always let the engine cool down. Hot components will burn
skin on contact.
• To reduce the risk of being burned, never open the hood if you
see or hear steam or coolant escaping from the engine compart­
ment. Wait until no steam or coolant can be seen or heard before
carefully opening the hood.
• Keep children away from the engine compartment .
• Never spill fluids on hot engine components. They can cause a
fire.
• Never touch the radiator fan. The auxiliary electric fan is
temperature controlled and can switch on suddenly.
• Never open the coolant reservoir cap when the engine is still
warm . The coolant system is pressurized and hot coolant could
spray out.
• Protect your face, hands and arm from steam or hot engine
coolant by placing a thick rag over the cap when you open the
coolant reservoir.
• If work on the fuel system or the electrical system is necessary :
- Always disconnect the battery.
- Never smoke or work near heaters or open flames . Fluids in
the engine compartment could start a fire.
- Keep an approved fire extinguisher immediately available.
• To avoid electrical shock and personal injury while the engine
is running or being started, never touch:
- Ignition cables
- Other components of the high voltage electronic ignition system.
• If you must perform a check or repair with the engine running: -First, fully apply the parking brake, move selector lever to "P"
(Park). .,
Vehicle care
I t •

Checkin g and fillin g -
--------------~-
•
the form of Service or Repair Orders that all schedu led maintenance
was performed in a time ly manner .•
Engine oil consumption
The engine in your vehicle depends on an adequate
amount of oil to lubricate and cool all of its moving parts.
In order to provide effective lubrication and cool ing of internal
engine components, all internal combustion engines consume a
certain amount of oil. Oil consumption varies from engine to engine
and may change significantly over the life of the engine. Typically,
engines with a specified break -in period (see~
page 279) consume
more oil during the break-in period than they consume after oi l
consumption has stabi lized .
Unde r normal conditions, the rate of oil consumption depends on
the quality and viscosity of the oil, the RPM (revolutions per minute)
at which the engine is operated, the ambient temperature and road
conditions . Further factors are the amount of oil dilution from water
condensation or fuel residue and the oxidation level of the o il. As
any engine is subject to wear as mileage builds up, the oil consump ­
tio n may increase over time unt il rep lacement of worn components
may become necessary.
With all these variables coming into play, no standard rate of oil
consu mption can be estab lished or specified. There is no a lternative
to regular and frequent checking of the oil level, see Note .
If the yellow engi ne oil level warning symbol in the instrume nt
cluster lights up, you should check the oil level as soon as
poss ible
with the oil dipstick~ page 313 . Top off the oil at your
earliest convenience~
page 314.
& WARNING
Before you che ck anything in the eng ine comp artment , alw ay s
read and heed all WARNINGS
~ & in "Working in the engine
c ompartment " on
page 309 .
0 Note
Driving with an insufficie nt o il level is l ikely to cause severe damage
to the engine.
[ i ] Tip s
• The oil pressure warning displ ay ce,. is not an indi cat or of the oil
level . Do not rely on it. Instead , check the oil level in your engine at
regular interv als , prefe rably ea ch time you refuel , and always before
going on a long trip.
• If you have the impression your engine consumes excessive
amoun ts of oi l, we recommend tha t you consult your Audi dealer to
have the cause of your concern properly diagnosed . Keep in mind
that the accurate measureme nt of oil consumption requires great
care and may take some time. Your Audi dealer has instructions
about how to measure oil consumption accurately. •
Checking the engine oil level
Vehicle care I t •
Fig. 2 65 Illu stra tion of
pri nciple 1 : Mar ker s on
oi l d ips tick ...

Tires a nd wh eels 111111 ________________________________ ::..:..:....::.=.....::.:..:..:..::..:___:__ _ ___:,___
•
Sidewa ll
means that portion of a tire between the tread and bead.
Speed ra ting means the speed at which a t ire is designed to be driven for
extended periods of time. The ratings range from 93 mph (150 km/h)
t o 186 mph (298 km/h) =>
page 340. You may not find this informa ­
tion on all tires because it is not required by law.
The speed rating letter code, where applicab le, is molded on the tire
sidewa ll and indicates the maximum perm issible road speeds=>
&
in "Winter tires" on page 343.
T ire pre ssu re m onit orin g sys te m *
means a system that detects when one or more of a vehicle's tires
are under inflated and illuminates a low tire pressure warning tell­
tale.
Tre ad
means that portion of a tire that comes into contact with the road .
Tread sepa ra ti on
means pu lling away of the tread from the tire carcass.
Tr ea dw ear indi cato rs ( TW I)
means the projections with in the principal grooves designed to give
a visual indication of the degrees of wear of the tread . See
~ page 337, "Tread Wear Indicator (TWI)" for more information on
measuring tire wear.
U ni form Tire Q ua lity G radin g
is a tire information system developed by the United States National
Highway Traffic Safety Administration (N HTSA) that is designed to
help buyers make re lative comparisons among tires. The UTQG is
not a safety rating and not a guarantee that a tire will last for a
prescribed number of miles (kilometers) or perform in a certain way .
I t simply gives tire buyers additional information to combine with
other considerations, such as price, brand loya lty and dealer recom -mendations
. Under UTQG, tires are graded by the tire manufac ­
t urers in three areas : treadwear, traction, and temperature res is ­
tance. The UTQG information on the tires, molded into the sidewal ls .
U .S . DOT Tir e Identifi cation Numb er (TIN )
This is the tire's "ser ia l number" It begins with the letters "DOT" and
indicates that the tire meets a ll federa l standards . The next two
numbers or letters indicate t he plant where it was manufact ured,
and the last four numbers represent the week and year of manufac­
ture. For example,
DOT ... 2 20 7 ...
means that the tire was produced in the 22th week of 2007 . The
other numbers are marketing codes that may or may not be used by
the tire manufacturer . This information is used to contact
consumers if a tire defect requires a reca ll.
V ehi cle ca pac ity w eig ht
means the rated cargo and luggage load plus 150 lbs . (68 kilograms)
times the vehicle's total seating capacity as listed on the label
located either on the d river's side 8 -pillar or on the inside of the fuel
filler flap.
V eh icle max imum load on the tire
means that load on an individual tire that is determined by distrib­
uting t o each ax le its share of the max imum loaded vehic le weight
and dividing by two.
V ehicle normal load on the tire
means that load on an individual tire that is determined by distrib­
uting t o each ax le its share of the curb weight, accessory weig ht,
and normal occupant weight (distributed in accordance with table
below =>
page 330) and dividing by two . _.,
Vehicle care I t •

___ T_ i_ r_e _s_ a_ n_ d_ w_ h_ e_ e _ ls _________________________________________________ _
Occupant loading and distribution for vehicle normal load for various designated seating capacities
Designated seating capacity , num­
ber of occupants
4
5
Cold tire inflation pressure
Vehicle no rmal load, number of
oc cupants
2
3
Occupant distribution in a normally
loaded vehicl e
2 in front
2 in front, 1 in b ack sea t
Tire pressure affects the overall handling, performance and safety of a vehicle.
Fig. 274 Tire pressure
label: located either on
driver 's side B-pillar or
inside the fuel filler flap
T IRE AND LOADING INFORMATION
T IRE SIZE COLD TIRE PRESS URE
FR ONT -KPa, - PSI
REAR -KPa, - PSI
I.:: SPARE -KPa, -PSI Fig . 275 Tire pressure
label
Maintaining proper tire pressure is one of the most important
things you can do to help avoid sudden tire failure. Underinflated
tires are a major cause of sudden tire failure. Keeping tires at the
right pressure is also important for safe and responsive vehicle
handling, traction, braking and load carrying. Tire pressures are
particularly important when the vehicle is being driven at higher
speeds, and then especially when heavily loaded even within the
permissible load-carrying capacities approved for your vehicle.
The recommended tire pressures for your Audi depend on the kind
of tires on your vehicle and the number of passengers and/or
amount of luggage you will be transporting.
•
Tire pressure generally refers to the amount of air in a tire that it
needs it to do its job and safely carry the combined load of the entire
vehicle and its contents . Tire pressure is measured in kilopascals
(kPa), the international measuring unit and in pounds per square
inch (PSI). Tire pressure is based in part on the vehicle's design and
load limit -the greatest amount of weight that the vehicle can carry
safely and the tire size. The proper tire pressure is frequently
referred to as the "recommended cold tire inflation pressure ." Air in
the tires expands when the tire heats up because of internal friction
when it flexes in use. The tire pressure is higher when the tire has
warmed up than when it is "cold." It is the inflation pressure in a
"cold" tire that counts. Therefore, you should never let air out of a
warm tire to match "cold tire inflation pressure " recommendations .
The tires would then be underinflated and could fail suddenly. On
USA vehicles, the tire pressure label is located on the driver's
side 8-pillar . On Canada vehicles, the tire pressure label is located
either on the driver's side 8 -pillar or inside the fuel filler flap . The tire
i.,.

Tires and wheels -________________ w-.
•
pressure label lists the recommended cold tire inflation pressures
for the vehicle at its maximum capacity weight and tires that were
on your vehicle at the time it was manufactured.
If you wish to improve comfort when operating the vehicle at
normal load (up to 3 occupants), you can adjust tire pressures to
those specified for normal vehicle load. Before operating the vehicle
at maximum load , you must increase the tire pressures to those
specified for maximum vehicle load
=> &.
Bear in mind that the tire pressure monitoring system* can only
monitor the tire pressures you have stored. The system does not
recognize the load condition of your vehicle .
The effec tiveness of the tire pressure mon itoring system* will be
impaired if you store normal load pressures but then operate the
vehicle at its maximum load=>&. See the
illustration=>
page 330, fig. 274 for the location of the label
either o n driver's side 8-pillar or inside the fuel filler flap (color of
the actual label and exact location on the vehicle will vary slight ly).
Note that the following tab le is accurate at the time of going to
press and is subject to change. In the event of discrepancies, the t ire
pressure label (On USA vehicles, the tire pressure label is located on
the driver's side 8-pillar. On Canada vehicles, the tire pressure label
is located either on the driver 's side 8-pillar or inside the fuel fil ler
flap) always takes precedence.
The table below lists the recommended cold tire inflation pressures
for the Audi mode l covered by your Owner's Literature at the
vehicle's capacity weight and the tire sizes installed on the respec­
tive models as original equipment, or as a factory option.
Engine
(displace­
ment in
liter) Tire designation
Tire pressure front Tire pressure rear
8-cylinder
4.2
8-cylinder
4 .2 L 255/45 R18 99H All Season
255/40 R19100V
XL All Season
255/40 R19
1 00Y XL High Performance
275/35 R20 102Y XL High Performance
255/45 R18 99H All Season
255/40 R19 100V XL All Season
255/40 R19 1 00Y XL High Performance
275/35 R20 102Y XL High Performance
normal load conditional
kPA
33 230
36 250
33 230
38 260 33 230
36 250
33 230
38 260
full load
condit ion
PSI
33 230
38 260
33 230
41 280
35 240
38 260
35 240
41 280
Vehicle care
normal load full load
conditional condition
kPA PSI kPA
30
210
33 230
33 230 36 250
30 210 33 230
35 240
44 300
30 210 33 230
33 230 36 250
30 210
33 230
35 240 44 300
I t •

Tires and wheels -
----------------
•
& WARNING (continued)
• The brakes on a vehicle that has been overloaded may not be
able to stop the vehicle within a safe distance.
• Tires on a vehicle that has been overloaded can fail suddenly
causing loss of control and a crash.
• Always make sure that the total load being transported -
including the weight of a trailer hitch and the tongue weight of a
loaded trailer -does not make the vehicle heavier than the
vehicle's Gross Vehicle Weight Rating.
& WARNING
• Incorrect tire pressures and/or underinflation can lead to a
serious or fatal accident.
• Incorrect tire pressures and/or underinflation cause increased
tire wear and can affect the handling of the vehicle.
• Incorrect tire pressures and/or underinflation can also lead to
sudden tire failure, including a blowout and sudden deflation,
causing loss of vehicle control. •
Checking tire pressure
The correct tire pressure for the tires originally installed
on your vehicle is listed on the tire pressure label located
either on driver's side 8-pillar or inside the fuel filler flap.
The recommended tire pressures are on the tire pressure label and
in the table~
page 330, "Cold tire inflation pressure".This means
that the pressure must be checked and adjusted when the tire has
not been driven for more than a couple of miles (kilometers) at low
speeds during the previous three hours. Air in the tires expands
when the tire heats up as a result of internal friction as it flexes in
use. The tire pressure is higher when the tire has warmed up than
when it is "cold ." It
is the inflation pressure in a "cold" tire that counts. Therefore, you
should never let air out of a warm tire to match "Cold tire inflation
pressure" recommendations~
page 330. The tires would then be
underinflated and could fail suddenly.
The tire pressure label on your Audi lists the recommended cold tire
inflation pressures at maximum capacity for the new, original equip ­
ment tires that were on your vehicle at the time it was manufac­
tured. For the location of the label
~ page 330, fig. 274.
Most tires lose air naturally over time. They can also lose some air if
you drive over a pothole or hit a curb while parking. It is usually not possible to see whether the radial tires used today are underinflated
just by looking at them.
Therefore, be sure to check tire pressures at least once a month and
always before going on a long trip. Make sure to take the number of
people and the amount of luggage into account when adjusting tire
pressure for a trip -even one that you would not consider to be
"long ." See~
page 335, "Tires and vehicle load limits" for more
important information.
Always use an accurate tire pressure gauge when checking and
adjusting inflation pressures . Check all of the tires and be sure not
to forget the spare tire . If the pressure in any tire is too high when
the tire is "cold," let air out of the tire slowly with the edge of the tire
gauge and keep checking the pressure until you reach the pressure
that is correct for the load (passengers and luggage) and kind of
driving you plan to do.
If the pressure in any tire is too low, note the difference between the
pressure in the cold tire and the pressure you need and add the air
that you need to reach the correct pressure for the vehicle load
(passengers and luggage) for the tires on your vehicle as listed on
the on your vehicle and in this manual and the kind of driving you
plan to do.
Never exceed the maximum inflation pressure listed on the tire
sidewall for any reason.
Remember that the vehicle manufacturer, not the tire manufacturer,
determines the correct tire pressure for the tires on your vehicle. .,,_
Vehicle care I t •

-Tires and wheels
---------------------------------------------
It is important to ch eck the ti re pressure when the tires are cold .
• Read the req uire d tire p re s su re from the tire press ure la b el. On
USA vehicles, the tire p ressure label is located on the driver's side
8 -p illar. On Canada vehic les, the tire p ressure label is located either
on the driv er's sid e 8-pill ar or ins ide t he fuel fill er flap.
• Tur n the va lve stem cap c ounte r-cl ockwise to rem ove it fr om t he
tire valv e.
• Place th e a ir p re s sur e ga uge on th e valve .
• Th e tire pressures should only be checked and adjusted when
th e tires are col d. The s lig htly raise d pres sures of wa rm tires m ust
not be r educ ed .
• Adjus t the tire pre ssu re to the l oad you are carrying.
• Reinstal l the valve stem cap on the valve.
When should
I check the tire pressure?
The correc t tir e pr ess ure is especiall y important a t hi gh speeds . The
pressu re should the re fore be checked at l east once a mont h an d
a lways bef ore sta rting a j ourn ey . D o not for get to chec k the ti re pr es­
su re for the s pare wh eel
::::> page 352.
When should I adjust the tire pressures?
Adjust the tire pr essure to the load you are carrying . After changing
a whee l or re plac ing w hee ls you have to adj ust th e tire pre ssu res on
a ll whee ls. I n ad ditio n, you must t hen stor e the ne w tire pr essu res
in t he tire pres sure mon it o ring system *=> page
41.
& WARNING
Incorrect tire pressures and /or underinflation can lead sudden tire
failure, loss of control, collision , serious personal injury or even
death .
• When the warning symbol appears in the instrument
cluster, stop and inspect the tires .
& WARNING (continued)
• Incorrect tire pressure and /or underinflation can cause
increased tire wear and can affect the handling of the vehicle and
stopping ability .
• Incorrect tire pressures and/or underinflation can also lead to
sudden tire failure , including a blowout and sudden deflation,
causing loss of vehicle control .
• The driver is responsible for the correct tire pressures for all
tires on the vehicle. The applicable pressure values are located on
a sticker on the driver's side B-pillar or on the inside of the fuel
filler flap.
• Only when all tires on the vehicle are filled to the correct pres­
sure , the tire pressure monitoring system* can work corre ctly.
• The use of incorrect tire pressure values can lead to accidents
or other damage . Therefore it is essential that the driver observe
the specified tire pressure values for the tires and the correct pres­
sures for the function of the tire pressure mon itoring system* .
• Always inflate tires to the recommended and correct tire pres ­
s ure before driving off .
• Driving with underinflated tires bend more , letting them get
too hot resulting in tread separation , sudden tire failure and loss
of control.
• Excessive speed and /overloading can cause heat build-up ,
s udden tire failure and loss of control.
• If the tire pressure is too low or too high, the tires will wear
prematurely and the vehicle will not handle well.
• If the tire is not flat and you do not have to change a wheel
immediately , drive at reduced speed to the nearest service station
to check the tire pressure and add air as required. _..