2018 AUDI S4 fuel

an authorized Audi dealer or authorized Audi
Service Facility for assistance.
Fuel filler door emergency release
If the central locking system is faulty, the fuel
filler door can be unlocked manually.
Fig. 262 Luggage co mpartment: opening the side trim
panel
Fig . 263 Luggage compartment: fuel filler door e merge ncy
r elease
The emergency opening mechanism is located
behind the right side trim panel in the luggage
compartment.
... Open the cover in the side panel ¢fig. 262.
... Loosen the loop c;, fig. 263 from the retainer
and then pull on the loop carefully
¢(D . The
filler door is released .
... Press on the left side of the fuel filler door to
open it
¢ page 317, fig. 260.
(D Note
Only pull on the loop until you feel resistance.
You will not hear it release . Otherwise you
could damage the emergency release mecha­
nism.
Checking and Filling
Selective catalytic
reduction (AdBlue/DEF)
General information
Applies to: vehicles with selec tive catalytic reduction
In vehicles with selective catalytic reduction, a
urea solution (AdBlue/DEF) is injected into the
exhaust system in front of a nitrogen oxide cata­
lytic converter to reduce nitrogen emissions. The
urea solution is known as Ad Blue or DEF (Diesel
Exhaust Fluid). The information that follows w ill
use the name AdBlue.
The Ad Blue is carried in a separate tank in the ve­
hicle. The AdBlue usage accounts for approxi­
mately 1.0% to 4 .0% of the diesel fuel that is
used .
When a message about refilling the AdBlue ap­
pears in the instrument cluster display, you must
refill the AdBlue yourself or have it refilled by an
authorized Audi dealer or authorized Audi Service
Facility
c;, page 320 .
{D Tips
-The display indicates the distance remaining
that can be dr iven
c;, page 319. If the Ad Bl­
ue tank is completely empty, the engine will
not start again after the ignition is switched
off.
-Ad Blue is required by law to operate this ve­
hicle.
Messages in the instrument cluster display
Appl ies to: vehicles wi th selective catalytic reduction
The display indicates if the Ad Blue level is low or
if there is a system malfunction.
AdBlue level low
You will be informed in the instrument cluster
display if the AdBlue in the tank drops below a
certain level. Add at a minimum the amount of
AdBlue shown in the message:
II Refill with at least x qt (l) Ad Blue. Range
x mi (km )
319

Checking and Filling
This message appears when there is only enough
Ad Blue left to drive the distance indicated in the
instrument cluster . Fill the Ad Blue .
• Refill with at least x qt (l) Ad Blue. No en­
gine start in x mi (km). See owner's manual
This message appears when there is only enough
Ad Blue left to drive the distance indicated in the
instr ument cluster. Fill the Ad Blue. Otherwise
the engine will not start again if you stop it once
the d istance indicated has been driven .
• Refill with at least x qt (l) AdBlue. Engine
start not possible . See owner's manual
This message appears when the AdBlue tank is
empty. Fill the AdB lue. Otherwise you will not be
able to start the engine again once you stop it .
The AdBlue must be refilled when the amount in
the tank has reached the minim um level
c::> page 320, Preparation.
Incorrect filling/system malfunction
A message appears if the Ad Blue tank was filled
with a fluid other than AdBlue and the system has detected that the tank was fi lled incorrectly ,
or if there is a system malfunction .
II Ad Blue: malfunction! No engine start in
x mi (km). See owner's manual
This message appears when it is only possible to
drive the d istance ind icated in the instrument
cluster. Drive to the nearest authorized Audi
dealer or authorized Aud i Serv ice Facility to have
the malfun ction corrected. Otherwise the engine
will not start again if you stop it once the dis­
tance indicated has been driven .
• Ad Blue: malfunction! No engine start possi­
ble. See owner's manual
This message appears if the system has detected
that the tank was filled incorrectly or that there
is a malfunction . Drive immediately to the near ­
est authorized Aud i dealer or authorized Audi
Service Facility to have the malfunction cor rect­
ed. Otherwise you will not be able to start the en­
g in e again once you stop it .
320
Preparation
App lies to : vehicles with selective cata lyt ic reduct ion
Fig. 264 R ig ht re ar sid e o f th e ve hicle: removing th e Ad B l­
ue cap
The Ad Blue tank open ing is located near the die­
sel tank opening. Add at least the amount of
Ad Blue shown in the instrument cluster display.
This is the minimum amount required to ensure
the system detects the refilling and to start the
engine. You can add a maximum of 6 .3 gallons
(24
L) .
Requ irement: the request to add Ad Blue must
appear in the instrument cluster display .
.. Switch the ignition off.
.. Open the tank fille r doo r c::> page 317 .
.. Turn the tank filler neck cap to the left to re­
move
c::> fig. 264 .
.. Refill Ad Blue using a pump no zzle c::> page 321,
a canister c::> page 321 or a bottle c::>page 321.
A WARNING
AdBlue can irritate the skin, eyes and respira­
tory system .
If there is contact with the fluid,
flush immed iately w ith plenty of water . Con­
sult a physician if necessary .
(D Note
-Only use Ad Blue that conforms to the
standard ISO 22241-1. Do not mix any addi­
ti ves wi th the Ad Blue and do not dilute it
with water .
- Do not add AdBlue to the diesel tank or add
diesel fuel to the Ad Blue tank. Do not start
the engine under any circumstances if the
wrong fuel is filled in the tank. There is a

a co .... N ,....
N .... 0 0
3 co
risk of damaging the fuel tank system and
the engine . See an authorized Audi dealer or
authorized Audi Serv ice Facility for ass is­
tance.
-Ad B lue attacks surfaces such as painted ve­
hicle components, plastic and carpet. Re­
move the fluid as quickly as poss ible with a
damp cloth and plenty of cold wa ter. If the
Ad Blue has already crystallized, use warm
water and a sponge . Ad Blue residue that is
not removed will crystallize and can damage
the affected surface .
-Do not store refill bott les or canisters per­
manent ly in the veh icle. If the container
l ea ks, the escaping AdBl ue could damage
the veh icle inter ior.
-Do not allow AdBlue to come into contact
with clothing. If there is contact with the
fluid , flush immed iate ly w ith plenty of wa­
ter.
@ Tips
F ollow the Ad Blue m anufact urer's instr uc­
tions fo r use and storage .
Refilling AdBlue using a pump
Applies to: vehicles with selective catalytic reduction
.,. Open th e tank fi ller door ¢ page 317, fig . 260.
.,. T u rn the tank filler neck cap to the left to re­
move
c:> page 320 , fig . 264.
.,. Refill AdBlue un til the pump no zzle swit ches
off for the first time ¢ (\1) .
.,. Close the filler neck . ¢ page 322, Completing
AdBlue refill
0 Note
-The pump nozzle handle must be pointing downward when filling . Otherwise the
pump noz zle w ill not sw itch
off automat i­
ca lly
c:> Q) in Preparation on page 320.
-Do not continue filling once the pump noz­
zle automatically switches
off for the first
time . The AdBlue ta nk system could be
overfilled and leak Ad B lue
c:> (D in Prepara­
tion on page 320 .
Check ing and Filling
Refilling AdBlue using a canister
Applies to: vehicles with selective catalytic reduction
+®
Fig. 265 Can is te r w it h attachab le hose
.,. Remove the cover from the refill canis te r¢ .&.
in Preparation on page 3 20, ¢ (Din Prepara ­
tion on page 320 .
.,. Secure the end of the hose(!) on the open ing in
t he canister @by turn ing the hose to the rig ht.
.,. Remove the cap @from the other end of the
hose @ .
.,. Position the end of the hose @ on the filler
neck in the vehicle and turn the hose to the
r ight to tighten it .
.,. Lift the canister up and then tip it. Cont inu e
holding the canis ter in a tipped pos it ion until i t
is empty or until no more flu id flows into the
tank .
.,. Remove the canis ter and close the filler t ube
c:> page 322, Completing AdBlue refill .
(D Note
Only use refill canisters that a re approved fo r
your vehicle. Using ot her systems ca n cause
Ad B lue to leak.
© Tips
- An authorized Aud i dealer o r autho rized
Audi repair facility can tell you wh ich refill
canisters are approved for your vehicle.
- A permitted refill ca niste r contains app roxi­
mately 1.3 gallons (5 l ite rs) of Ad Blue .
Refilling AdBlue using a bottle
Applies to: vehicles with selective catalytic reduction
.,. Remove the cap from the refill bo ttle c:> .&. in
Preparation on page 3 20,
c:> (D in Preparation
on page 320 .
.,.
321

Check ing and F illing
"' Position the bottle on the filler tube and turn
the bottle clockwise unti l it stops turning.
"' Press lightly aga inst the bottom of the bott le
to empty it. Continue pressing the bottom of
the bottle until it is empty or unti l fluid stops
flowing into the tank .
"' Remove the bottle and seal the filler neck
¢ page 322, Completing AdBlue refill .
0 Note
Only use refill bottles that are approved for
your vehicle. Us ing other systems can ca use
Ad Blue to leak.
-You can obta in refill bottles from an author­
i zed Audi dealer or authorized A udi Service
F ac ility.
- A pe rm itted refill bottle conta ins approxi­
mately 0 .5 gallon ( 1.9 liters) of Ad Blue.
Completing AdBlue refill
Applies to: vehicles with selective catalytic reduction
Closing the filler neck
"'Turn the Ad Blue cap to the r ight on the filler
tube unti l th e cap cl ic k s into
p lace ¢.&. in
Prepara tion on page 320,
¢ (Din Preparation
on page 320 ..
"' Then press on the left side of the tank door un-
ti l it latches.
After filling
The vehicle must be driven so tha t the system
recognizes t hat the Ad B lue was refilled. This can
t ake severa l m in utes.
"' If there was no Ad Blue left in the tank and a
r ange of O mi (0 km) was shown in the d isplay,
swi tch the ign ition on fo r abo ut 30 seconds be­
f ore star ting the engine .
(D Tips
Ad Blue in the tank can free ze at very low tem­
pera tures. If this happens, the system will
not detect that the AdB lue was refilled and it
w ill contin ue to inform you of the low AdBlue
322
leve l. The message tu rns off as soon as the
tank thaws out again .
Emissions control
systems
Cat alytic converter
Applies to: vehicles with gasoline engines
T he vehicle may only be driven w ith un leaded
gaso line, otherwise the catalytic converter will be
destroyed .
Never drive unti l the tan k is comp lete ly empty .
T he irregu lar supply of fuel that resu lts from that
can cause eng ine misfires. Uncombusted fuel will
enter the exhaust system , which can cause over­
heating and damage to the catalytic converte r.
Di esel particulate filt er
Applies to: vehicles with diesel engines
The diese l particulate filter filters nearly all of
the soot part icles out of the exhaust. The filter
cleans itself automat ica lly under norma l dr iv ing
cond it io ns. If the filter cannot clean itself (for ex­
amp le, because yo u are on ly driving short distan ­
ces), the filter becomes clogged with soot and
the
1111 i ndicato r light for the diese l particulate
filte r tu rns
on ¢ page 33.
_&. WARNING
The tempera ture o f the e xhaust sys tem is
h igh, both when driving and a fter stopping
the engine.
-
-Never tou ch the e xhaus t tail p ipes o nce they
have become hot. This cou ld resu lt in burns.
-D o not p ark your vehicle over flamm able
materials such as grass or leaves because
the hig h temperature of the emissions con­
trol system (catalyt ic converter or d iese l
pa rticu late filter) co uld start a fire.
- Do not apply underbody protectant in the
exhaust system area, beca use this increases
the risk of f ire.

a co .... N ,....
N .... 0 0
3 co
(D Note
Driving with an insufficient oil level is likely to
cause severe damage to the engine.
@ Tips
-The oil pressure warning display. is not
an indicator of the oil level. Do not rely on
it. Instead, check the oil level in your en­
gine at regular intervals, preferably each
time you refuel, and always before going
on a long trip.
-If you have the impression your engine con­
sumes excessive amounts of oil, we recom­
mend that you consult an authorized Audi
dealer to have the cause of your concern
properly diagnosed. Keep in mind that the
accurate measurement of oil consumption
requires great care and may take some
time. An authorized Audi dealer has instruc­
tions about how to measure oil consump­
tion accurately.
Checking the engine oil level and adding
engine oil
The engine oil level can be checked in the Info ­
tainment system
Fig. 269 Engine compa rtment: eng ine oil filler opening
cove r
Checking the engine oil level
- Park the vehicle on a level surface.
- Shut the engine off when it is warm.
0 N
-N
" 00 IX)
-Switch only the ignition back on. Wait approxi-
mately two minutes so that the engine oil can
flow back into the oil pan .
Checking and Filling
- Select in the Infotainment system: the !MENUI
button > Vehicle > left control button > Service
& checks > Oil level.
-Check the oil level in the Infotainment system
display. Add engine oil if the bar in the oil level
indicator is just before "min".
Adding engine oil Follow the safety precautions
~&. in Working in
the engine compartment on page 323.
- Stop the engine and open the hood
~page 324 .
-Unscrew the cap~ on the engine oil filling
opening
~ fig. 269, Qpage 325.
- Carefully add O .S quart (O .S liter) of the correct
oil
~ page 325.
- Close the engine oil filler opening cap.
- Close the hood, restart the ignition after two
minutes and read the current oil level in the In ­
fotainment system.
A WARNING ...__ --When adding oil, do not let oil drip onto hot
engine components. This increases the risk
of afire.
-You must secure the cap on the oil filler
opening correctly so that oil does not leak
out onto the hot engine and exhaust system
when the engine is running, because this is
a fire hazard.
-Always clean skin thoroughly if it comes into
contact with engine oil.
0 Note
- The engine oil level must not be under the
"min" marking, because this increases the
risk of engine damage.
- If the message II Please reduce oil level
appears, there is too much oil in the engine
and there is a risk of damaging the catalytic
converter and engine. Do not start the en­
gine. Contact an authorized Audi dealer or
authorized Audi Service Facility to have ex­
cess engine oil extracted if necessary.
- Do not mix any additional lubricants into
the engine oil. Damage caused by such addi-
tives is not covered by the warranty.
IJJ>
327

Wheels
Wheels
Whee ls and Ti res
General information
.,. Check your tires regularly for
damage (punctures, cuts, cracks
and bulges). Remove foreign ob ­
jects from the tire tread.
.,. If driving over curbs or similar
obstacles, drive slowly and ap­ proach the curb at an angle.
.,.Have faulty tires or rims re­
placed immediately.
.,.Protect your tires from oil,
grease and fuel.
.,.Mark tires before removing
them so that the same running
direction can be maintained if
they are reinstalled .
.,. Lay tires flat when storing and
store them in a cool, dry location
with as little exposure to light as
possible.
(D N ote
-Please note that summer and
winter tires are designed for
the conditions that are typical in those seasons . Audi recom­
mends using winter tires dur­
ing the winter months . Low
temperatures significantly de­ crease the elasticity of summ­
er tires, which affects traction
33 4
and b raking ability. If summer
tires are used in very cold
temperatures, cracks can form
on the tread bars, resulting in
permanent tire damage that
can cause loud driving noise
and unbalanced tires.
-Burnished, polished or chromed rims must not be used in winter driving condi­
tions. The surface of the rims
does not have sufficient corro­
sion protection for this and
could be permanently dam­
aged by road salt or similar
substances.
Tire designations
F ig. 27 4 Tire des ignat ions on the side-
wall II>

0 C0 .-< N ..... N .-< 0
~ a:,
Bead separa tion
means a breakdown of the bond
between components in the bead.
Cord
means the strands forming the
plies in the tire .
Cold tire inflation pressure
means the tire pressure recom­
mended by the vehicle manufac­
turer for a tire of a designated size that has not been driven for
more than a couple of miles (kilo­
meters) at low speeds in the
three hour period before the tire
pressure is measured or adjusted .
Curb weight
means the weight of a motor ve­
hicle with standard equipment in­
c luding the maximum capac ity of
fuel, oi l, and coolant, a ir condi­
tioning and add itional weight of
optional equipment.
E xtra load tire
means a tire designed to operate
at higher loads and at h igher in ­
flation pressures than the corre­ sponding standard tire. Extra load
tires may be identified as
"X L",
"xl", "E XTRA LOAD" , or "RF" on
the s idewal l.
Wheels
Gross Axle Weight Rating
( " GAWR")
means the load-carrying capacity
of a single axle system, measured
at the tire -ground interfaces.
Gross Vehicle Weight Rating
(" GVWR ")
means the max imum total loaded
weight of the vehicle.
Groove
means the space between two ad­
jacent tread ribs .
Load rating (code)
means the maxim um load that a
tire is rated to carry for a given in­
flat ion pressure . You may not f ind
this informat ion on all tires be ­
cause it is not required by law.
Maximum load rating
means the load rating for a tire at
the maximum permissible infla­
tion pressure for that tire .
Maximum loaded vehicle
weight
means the sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity we ight , and
(d) Production options we ight
33 7

0 C0 .-< N ,... N .-< 0
~ a:,
-The tire must flex more if the
tire pressure is too low or if
the vehicle speed or load are
too high. This heats the tire up
too much . This increases the
risk of an accident because it
can cause the tire to burst and result in loss of vehicle con­
trol.
-Incorrect tire pressure in­
creases tire wear and has a
negative effect on driving and
braking behavior, which in­
creases the risk of an accident .
(D Note
Replace lost valve caps to re­
duce the risk of damage to the
tire valves.
Tire pressure table
Please note that the information
contained in the following table
was correct at the time of print­ ing, and the information is sub­
ject to change. If there are differ­
ences between this information
and the tire pressures specified
on the label on the driver's side B­
pillar, always follow the specifica­
tion on the B -pillar label
¢ page 344, fig. 2 76.
Wheels
'® For the sake of the environment
-Tire pressure that is too low
increases fuel consumption.
-Fuel consumption may also in­
crease when driving with the
comfort tire pressure is se­
lected.
Audi recommends using the
tire pressure specified for a
normal load
¢ table on
page 346
or for a full load
when the vehicle is partially
loaded.
Make sure that the tire designa­
tion on your tire matches the des­ ignation on the tire pressure label
and the tire pressure table.
The following table lists recom­ mended tire pressures in cold
tires according to the load and
the size of the tires installed .
..
345