2018 AUDI TT ROADSTER tire size

Intelligent Technology
Intelligent Technology Electronic stabilization
control (ESC)
Description
Elect ronic stabili zation control ( ESC) suppo rts
driver safety. It red uces the risk of slipping and
improves dr iving stabi lity. ESC detects crit ica l sit­
uations such as the vehicle overstee ring and un­
dersteeri ng or the w heels are sp inning. The vehi­
cle is stabilized by app lying the brakes or reduc ­
i n g e ngine torque . When the ESC engages, the
liJ indicato r light bli nks in t he instr ument clus­
t er.
The fo llow ing systems are in tegrated in the ESC:
Anti-lock braking system (ABS)
ABS p reve nts the whee ls from lock ing whe n brak ­
ing. The vehicle can st ill be steered even d uring
hard brak ing. Apply steady press ure to the bra ke
pedal. Do not pump the pedal. A puls ing in t he
b rake pedal indicates that the system is act ing to
s tabili ze the vehicle .
Brake assist system
The brake assist system can decrease brak ing dis­
tance . It inc reases brak ing power when the d river
presses the brake pedal q uick ly in eme rgency sit­
uations . You must press and hold t he b rake pedal
until the dangerous si tuatio n is ove r.
Anti-slip regulation (ASR)
ASR red uces eng ine power when the d rive wheels
begin sp inning a nd adapts the force to the road
conditions . This makes it easie r to start, acceler­
ate and dr ive u p hill s.
Electronic differential lock (EDL)
E DL applies the brakes to a wheel that sta rts
spi nning and t ransfe rs the d rive power to the
other driving wheels. This f unction is not availa­
b le at higher speeds.
In extreme cases, EDL automatically sw itches off
to keep the brake on the b raked wheel from over­
heati ng. The vehicle is st ill work ing correctly. EDL
86
will swi tc h on again automatically when condi ­
tions have retu rned to normal.
Power steering
The ESC can also support veh icle stab ility
t hr ough stee rin g.
Selective wheel torque control
Se lective wheel to rque con trol is used when d riv­
i ng on curves . The front whee l on the ins ide of
t h e curve or bo th whee ls on the i nside of th e
cu rve are braked se lective ly as needed. This al­
l ows mo re pre cise dr iving in curves .
_&. WARNING
-The E SC and i ts in teg ra ted systems cannot
overcome the lim its imposed by natura l
phys ica l laws. This is es pec ially important
on s lippery or wet roa ds.
If the systems be­
gin acting to stabilize yo ur vehicle, you
should immediately a lter your speed to
match the road and traffic conditions. Do
no t le t the inc reased safety p rovi ded tempt
you into taking risks. This could increase
y o ur r is k of a c oll is ion.
- Please note the r is k of a coll is ion increases
w hen dr iv in g fast, especially t hrough curves
a nd on sl ippery or wet r oads, and w hen dr iv­
ing to o cl ose to obje cts ahead. T he ES C and
it s i ntegrated systems cannot a lways pre ­
vent co llisions
-there is st ill a risk of acci­
dents!
- Press the accelerator peda l caref ully when
accelerating on even, slippery sur faces such
as ice and snow. The drive wheels can spin
even when these control systems a re instal­
led and this can affect driving stability and
increase the risk of a collision.
(0 Tips
- The ABS and ASR only funct ion correctly
when a ll four wheels have a sim ila r wear
co nditio n. D iffere nt tire sizes can lead to a
red uction in engin e power.
- You may hear noises when the systems de­
sc ribed are working .

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Safety belts
General notes
Always wear safety belts!
Wearing safety belts correctly saves lives!
This chapter exp lains why safety be lts are neces­
sary, how they work and how to adjust and wear
them correctly.
• Read all the information that follows and heed
all of the instructions and WARNINGS.
A WARNING
Not wearing safety belts or wearing them im­
properly increases the risk of serious personal
injury and death.
- Safety belts are the s ingle most effective
means ava ilable to reduce the risk of serious
injury and death in automobile accidents.
For your protection and that of your passen­
gers, always correctly wear safety belts
when the vehicle is moving.
- Pregnant women, injured, or physically im­
paired persons must also use safety belts.
Like all vehicle occupants, they are more
likely to be seriously injured if th ey do not
wear safety belts. The best way to protect a
fetus is to protect the mother -throughout
the entire pregnancy.
Number of seats
Your veh icle has two seating positions. Each seat­
ing position has a safety belt.
A WARNING
Not wearing safety belts or wearing them im­
properly increases the risk of serious personal
injury and death.
- Never strap more than one person, includ­
ing sma ll ch ildren, into any belt.
It is espe­
ci ally da ngerous to place a safety belt over a
ch ild sitting on your lap.
- Never let more people ride in the vehicle
than there are safety belts available.
Safety belts
-Be sure everyone riding in the vehicle is
properly restrained with a separate safety
belt or child restraint.
4 Safety belt warning light
Your vehicle has a warning system for the driver
and front seat passenger to remind you about the importance of buckling up.
Fig. 152 Safety belt warn ing ligh t in the instrument clus ­
ter -en larged
Before driving off, always:
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• Fasten your safety belt and make sure you wear
it properly.
• Make sure that your passengers also buckle up
and properly wear their safety belts.
• Protect ch ildren with a child restraint system
appropr iate for the size and age .
The warning light . in the instrument cluster
lights up when the ignit ion is switched on as a re­
minder to fasten the safety belts . In add ition, a
warning tone will sound for a certain period of
time .
Fasten your safety belt and make sure that your
passengers also properly put on their safety
belts.
A WARNING
-
- Safety belts are the single most effect ive
means available to red uce the risk of serious
i njur y and death in automobile accidents.
Fo r your protection and that of yo ur passen­
gers, always correctly wear safety belts
when the vehicle is moving .
- Fail ure to pay attention to the warning light
that comes on cou ld lead to personal injury.
187

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Tire designations
Fig. 187 Tire designation on the side­
wall
(D Tires for passenger vehicles
(if applicable)
"P" indicates a tire for a passenger
vehicle . "T" indicates a tire desig­
nated for temporary use.
@ Nominal width
Nominal width of the tire be­
tween the sidewalls in millime­
ters. In general: the larger the
number, the wider the tire .
@ Aspect ratio
Height/width ratio expressed as a
percentage .
Wheels
@Tire construction
"R" indicates a radial tire.
® Rim diameter
Size of the rim diameter in inches.
® Load index and speed rating
The load index indicates the tire's
load-carrying capacity.
The speed rating indicates the
maximum permitted speed. Also
see
¢ &. in General information
on page 244.
"EXTRA LOAD", "xl" or "RF" indi­
cates that the tire is rei nforc ed or
i s an Extra Load tire .
Speed rat-
Maximum permitted speed
ing
p up to 93 mph (150 km/h)
Q up to 99 mph (160 km/h)
R up to 106 mph (170 km/h)
s up to 110 mph (180 km/h)
T up to 118 mph (190 km/h)
u up to 124 mph (200 km/h)
H up to 130 mph (210 km/h)
V up to 149 mph (240 km/h)a)
z above 149 mph (240 km/h)a)
w up to 168 mph (270 km/h)a)
y up to 186 mph (300 km/h)a)
a) For tires above 149 mph (240 km/h) ,
tire manufacturers sometimes use the
code "ZR".
245

windows, power seats, radio, and heater, to the extent that these
items are available as factory- in­
stalled equipment (whether in­
stalled or not) .
Aspect ratio
means the ratio of the height to
the width of the tire in percent .
Numbers of 55 or lower indicate a
low sidewall for improved steer­
ing response and better overall
handling on dry pavement .
Bead
means the part of the tire that is
made of steel wires , wrapped or
reinfo rced by ply cords and that is
shaped to fit the rim .
Bead separation
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 t ire pressure recom­
mended by the vehic le manufac­
turer for a tire of a designated
Wheels
three hour period before the tire
pressure is measured or adjusted .
Curb weight
means the weight of a motor ve­
hicle with standar d equipment in ­
c luding the maximum capacity of
f u el, oi l, and coolant, air condi ­
tioning and additional weight of
optional eq uipment.
Extra load ti re
means a t ire designed to operate
at higher loads and at higher in ­
flation pressures than the corre­
sponding s tandard tire. Extra load
ti res may be identified as
"XL",
"xl" "EXT RA LOAD" or "RF" on , ,
the sidewall.
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 maxim um total loaded
weight of the vehic le .
Groove
size that has not been driven for means the space between two ad -
~ more than a co uple of miles (kilo -jacent tread ribs . .,.
"
8 meters) at low speeds in the
" "' a:,
2 47

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" N .... 0
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beads are laid at substantially
90 degrees to the centerline of
the tread .
Recommended inflation
pressure
see ¢ page 247, Cold tire infla­
tion pressure .
Reinforced tire
means a tire designed to operate
at higher loads and at h igher in ­
flation pressures than the corre­
sponding standard tire. Rein­
forced tires may be identified as
"XL", "xl", "EXT RA L OAD", or "RF"
on the sidewa ll.
Rim
means a metal support for a tire
or a tire and tube assemb ly upon
which the t ire beads are seated .
Rim diameter
means nominal diameter of the
bead seat . If you change your
whee l size, you will have to pu r­
c h ase new t ires to match the new
rim diameter .
Rim size designation
means rim diamete r and width .
Rim width
means nominal distance between
rim flanges .
Wheels
Sidewall
means that portion of a tire be ­
tween the tread and bead .
Speed rating (letter code)
means the speed at which a tire is
designed to be driven for extend­
ed periods of time. The ra tings
range from
93 mph (150 km/h)
to
186 mph (298 km/h) ¢ table
on page 245 .
You may not find
this informat ion on all tires be ­
cause it is not required by law .
The speed rating letter code,
where applicable, is molded on
the tire sidewall and indicates t he
maximum pe rmissible roa d
speeds . See also ¢
A in General
information on page 244.
Tire pressure monitoring
system *
means a system that detects
when one or more of a vehicle's
ti res are underinflated and illumi ­
nates a low tire pressure warning
telltale .
Tread
means that portion of a ti re that
comes into contact with the road .
.,.
249

0
Vehicle maximum load on the
tire
means that load on an individual
tire that is determined by distrib­
uting to each axle its share of the
maximum loaded vehic le we ight
and dividing by two .
Vehicle normal load on the tire
means that load on an individual
tire that is determined by distrib ­
uting to each axle its share of the
curb weight, accessory weight,
and normal occupant weight (dis­
tributed in accordance
with ¢ ta­
ble on page 256)
and dividing by
two .
Occupant loading and distri­
bution for vehicle normal load
for various designated seating
capacities
Refer to the tire inflation pres­
sure label for the number of seat ­
ing positions . Refer to the tab le
¢
table on page 256 for the
number of people that corre­
spond to the vehic le normal load .
New tires or wheels
Audi recommends having all wo rk
on t ires or wheels performed by
~ an authorized Audi dealer or au-N
" ~ thorized Audi Service Facility. 0
" "' a:,
Wh eel s
These facilities have the proper
knowledge and are equipped with
the required tools and replace­ ment parts.
.,. New tires do not yet have the
optimum g ripping properties.
Drive carefully and at moderate
speeds for the first 350 miles
(500 km) with new tires .
i,.Qnly use tires w ith the same de­
sign, size (rolling circumfer ­
ence), and as close to the same
tread pattern as possible on all
four whee ls .
.,. Do not replace tires individually .
At least replace both tires on the
same axle at the same t ime.
.,. Audi recommends that you use
Audi Original Tires. If you would
like to use different tires , please
note that the tires may perform
differently even if they are the
same size
¢ ,& .
.,. If you would like to equip your
vehic le w ith a tire/r im combina­
tion that is different from what
was installed at the factory, con­
sult w ith an authorized Audi
dealer or authorized Audi Service
Facility before making a pur-
chase¢ ,&.. .,.
25 1

Wheels
Because the spare tire* is differ­
ent from the regular tires instal­ led on the vehicle (such as winter
tires or wide tires), only use the
spare tire* temporarily in case of
emergency and drive carefully
while it is in use. It should be re­ placed with a regular tire as soon
as possible.
Applies to: vehicles with all wheel
drive: all four wheels must be
equipped with tires that are the
same brand and have the same
construction and tread pattern so
that the drive system is not dam­
aged by different wheel speeds.
For this reason, in case of emer­
gency, only use a spare tire* that
is the same circumference as the
regular tires.
& WARNING ~ -
-Only use tire/rim combina­
tions and suitable wheel bolts
that have been approved by
Audi. Otherwise, damage to
the vehicle and an accident could result.
-For technical reasons, it is not
possible to use tires from oth­
er vehicles - in some cases,
you cannot even use tires from
the same vehicle model.
252
-Make sure that the tires you
select have enough clearance
to the vehicle. Replacement
tires should not be chosen simply based on the nominal
size, because tires with a dif­
ferent construction can differ greatly even if they are the
same size. If there is not
enough clearance, the tires or
the vehicle can be damaged and this can reduce driving
safety and increase the risk of
an accident.
-Only use tires that are more
than six years old when abso­
lutely necessary and drive
carefully when doing so.
-Do not use run-flat tires on
your vehicle. Using them when not permitted can lead to ve­
hicle damage or accidents.
- If you install wheel covers on
the vehicle, make sure they al­ low enough air circulation to
cool the brake system. If they
do not, this could increase the
risk of an accident.

Wheels
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 254, fig. 189.
Make sure that the tire designa­
tion on your tire matches the des-
Model/ Tire designation
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.
Tire pressure
Engine Normal load Maximum load
(up to 2 people)
front
PSI
TT : 245/45 R17 95Y 32
2.0 l
245/40 R18 93H 32
4-cylinder
245/40 R18 93Y 32
245/35 R19 93Y 35
255/30 R20 92Y 35
A WARNING
Please note the important safe­
ty precautions regarding tire
pressure ¢ page 254 and load
limits¢ page 256.
Tires and vehicle load limits
There are limits to the amount of
load or weight that any vehicle
and any tire can carry. A vehicle
that is overloaded will not handle
well and is more difficult to stop.
Overloading can not only lead to loss of vehicle control, but can al­
so damage important parts of the
vehicle and can lead to sudden
tire failure, including a blowout
256
kPA
220
220
220
240
240
rear front rear
PSI kPA PSI kPA PSI
29 200 33 230 30
29 200 33 230 30
29 200 33 230 30
32 220 35 240 32
32 220 38 260 32
and sudden deflation that can
cause the vehicle to crash.
kPA
210
210
210
220
220
Your safety and that of your pas­
sengers also depends on making
sure that load limits are not ex­
ceeded. Vehicle load includes ev­
erybody and everything in and on
the vehicle. These load limits are
technically referred to as the vehi­
cle's
Gross Vehicle Weight Rat­
ing
("GVWR").
The "GVWR" includes the weight
of the basic vehicle, all factory in­
stalled accessories, a full tank of
fuel, oil, coolant and other fluids
plus maximum load. The maxi­
mum load includes the number
of .,.