2019 MERCEDES-BENZ AMG GT ROADSTER Owner's Manual

requirements of the U.S. Department of Trans-
portation.
Manufacturer identification code: manufac-
turer identification code 0044provides details on
the tire manufacturer. New tires have a code
with two symbols. Retreaded tires have a code
with four symbols.
For further information about retreaded tires,
see (Y page 285).
Tire size: identifier0087describes the tire size.
Tire type code: tire type code0085can be used by
the manufacturer as a code to describe specific
characteristics of the tire.
Date of manufacture: date of manufacture0083
provides information about the age of a tire. The
first and second positions represent the week of manufacture, starting with "01" for the first cal-
endar week. Positions three and four represent
the year of manufacture. For example, a tire that
is marked "3214" was manufactured in week 32 in 2014.
i Tire data is vehicle-specific and may deviate
from the data in the example.
Tire characteristics This information describes the type of tire cord
and the number of layers in sidewall 0043and
under tire tread 0044.
i Tire data is vehicle-specific and may deviate
from the data in the example.
Definition of terms for tires and loading Tire ply composition and material used
Describes the number of plies or the number of
layers of rubber-coated fabric in the tire tread
and sidewall. These are made of steel, nylon,
polyester and other materials. Bar
Metric unit for tire pressure. 14.5038 pounds
per square inch (psi) and 100 kilopascals (kPa)
are the equivalent of 1 bar.
DOT (Department of Transportation)
DOT-marked tires fulfill the requirements of the U S Department of Transportation.
Normal occupant weight
The number of occupants for which the vehicle
is designed multiplied by 68 kilograms (150 lbs).
Uniform Tire Quality Grading Standards
A uniform standard to grade the quality of tires
with regards to tread quality, tire traction and
temperature characteristics. The quality grad-
ing assessment is made by the manufacturer
following specifications from the U.S. govern-
ment. The ratings are molded into the sidewall of the tire.
Recommended tire pressures The recommended tire pressure applies to the
tires mounted at the factory.
The Tire and Loading Information placard con-
tains the recommended tire pressures for cold
tires on a fully loaded vehicle and for the maxi-
mum permissible vehicle speed.
The tire pressure table contains the recommen-
ded pressures for cold tires for various operat-
ing conditions, i.e. differing load and speed con-
ditions.
Increased vehicle weight due to optional
equipment The combined weight of all standard and
optional equipment available for the vehicle,
regardless of whether it is actually installed on
the vehicle or not.
Rim
This is the part of the wheel on which the tire is
mounted.
GAWR (Gross Axle Weight Rating)The GAWR is the maximum gross axle weight
rating. The actual load on an axle must never
exceed the gross axle weight rating. The gross
axle weight rating can be found on the vehicle
identification plate on the B-pillar on the driver's
side. All about wheels and tires
279Wheels and tires Z

Speed rating
The speed rating is part of the tire identification. It specifies the speed range for which the tire is
approved.
GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight of the vehicle with fuel, tools, the spare wheel,
accessories installed, vehicle occupants, lug-
gage and the drawbar noseweight if applicable.
The gross vehicle weight must not exceed the
gross vehicle weight rating GVWR as specified
on the vehicle identification plate on the B-pillar
on the driver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permitted gross
weight of the fully laden vehicle (weight of the
vehicle including all accessories, vehicle occu-
pants, fuel, luggage and the drawbar nose-
weight if applicable). The gross vehicle weight
rating is specified on the vehicle identification
plate on the B-pillar on the driver's side.
Maximum loaded vehicle weight
The maximum weight is the sum of:
R the curb weight of the vehicle
R the weight of the accessories
R the load limit
R the weight of the factory installed optional
equipment
Kilopascal (kPa) Metric unit for tire pressure. 6.9 kPa corre-
sponds to 1 psi. Another unit for tire pressure is
bar. 100 kilopascals (kPa) are the equivalent of
1 bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall of
the tire. This specifies the load-bearing capacityof the tire more precisely.
Curb weight The weight of a vehicle with standard equipment
including the maximum capacity of fuel, oil and
coolant. It also includes the air-conditioning sys- tem and optional equipment if these are instal-
led in the vehicle, but does not include passen-
gers or luggage. Maximum load rating
The maximum tire load is the maximum permis- sible weight in kilograms or lbs for which a tire is
approved.
Maximum permissible tire pressure Maximum permissible tire pressure for one tire.
Maximum load on one tire Maximum load on one tire. This is calculated by
dividing the maximum axle load of one axle by
two.
PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratioRelationship between tire height and tire width
in percent.
Tire pressure
This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. The tire pressure is specified in pounds per
square inch (psi), in kilopascal (kPa) or in bar.
The tire pressure should only be corrected when
the tires are cold.
Cold tire pressure
The tires are cold:
R if the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
R if the vehicle has not been driven further than
1 mile (1.6 km)
Tread The part of the tire that comes into contact with
the road.
Bead
The tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in the bead to prevent the tire from coming loose from
the wheel rim.
Sidewall
The part of the tire between the tread and the
bead. 280
All about wheels and tiresWheels and tires

Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 5 lbs (2.3 kg). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-volt-
age battery, are not included in the curb weight
and the weight of the accessories.
TIN (Tire Identification Number) This is a unique identifier which can be used by
a tire manufacturer to identify tires, for example
for a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur- er's identity code, tire size, tire type code and
the manufacturing date.
Load bearing index
The load bearing index (also load index) is a code that contains the maximum load bearing capa-
city of a tire.
Traction
Traction is the result of friction between the tires and the road surface.
Treadwear indicators Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of 00CDin (1.6 mm)
has been reached.
Occupant distribution
The distribution of occupants in a vehicle at their designated seating positions.
Total load limit Nominal load and luggage load plus 68 kg
(150 lbs) multiplied by the number of seats in
the vehicle. Changing a wheel
Flat tire
The "Breakdown assistance" section
(Y page 250) contains information and notes on
how to deal with a flat tire. Rotating the wheels
G
WARNING
Interchanging the front and rear wheels may
severely impair the driving characteristics if
the wheels or tires have different dimensions. The wheel brakes or suspension components
may also be damaged. There is a risk of acci-
dent.
Rotate front and rear wheels only if the wheels and tires are of the same dimensions.
! On vehicles equipped with a tire pressure
monitor, electronic components are located
in the wheel.
Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at a qualified spe-
cialist workshop.
Always observe the instructions and safety
notes in the "Mounting a wheel" section
(Y page 282).
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires in
the center.
On vehicles that have the same size front and
rear wheels, you can rotate the wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,000 km). Depending on tire wear, this may
be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time a wheel is rota- ted. Check the tire pressure and reactivate the
tire pressure monitor if necessary. Direction of rotation
Tires with a specified direction of rotation have
additional benefits, e.g. if there is a risk of hydro- planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation. Changing a wheel
281Wheels and tires Z

An arrow on the sidewall of the tire indicates its
correct direction of rotation. Storing wheels
Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the tires
from oil, grease, gasoline and diesel. Mounting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground.
X Apply the electric parking brake manually.
X Bring the front wheels into the straight-ahead
position.
X Shift the transmission to position 005D.
X Switch off the engine.
X With KEYLESS-GO start function or vehi-
cles with KEYLESS-GO:
open the driver's
door.
The vehicle electronics are now in key posi-
tion 0092. This is the same as the SmartKey
having been removed.
or X Remove the SmartKey from the ignition lock.
X If included in the vehicle equipment, remove
the tire-change tool kit from the vehicle.
X Safeguard the vehicle against rolling away.
Securing the vehicle to prevent it from
rolling away If your vehicle is equipped with a wheel chock, it
can be found in the tire-change tool kit
(Y page 249). The folding wheel chock is an additional safety
measure to prevent the vehicle from rolling
away, for example when changing a wheel.
X Fold both plates up 0043.
X Fold out lower plate 0044.
X Guide the lugs on the lower plate fully into the
openings in base plate 0087. X
Place chocks or other suitable items under
the front and rear of the wheel that is diago-
nally opposite the wheel you wish to change.
Raising the vehicle G
WARNING
If you do not position the jack correctly at the appropriate jacking point of the vehicle, the
jack could tip over with the vehicle raised.
There is a risk of injury.
Only position the jack at the appropriate jack-
ing point of the vehicle. The base of the jack
must be positioned vertically, directly under
the jacking point of the vehicle.
! Only position the jack at the appropriate
jacking point of the vehicle. Otherwise, you
could damage the vehicle.
Observe the following when raising the vehi- cle:
R To raise the vehicle, only use the vehicle-spe-
cific jack that has been tested and approved
by Mercedes-Benz. If used incorrectly, the
jack could tip over with the vehicle raised.
R The jack is designed only to raise and hold the
vehicle for a short time while a wheel is being
changed. It must not be used for performing
maintenance work under the vehicle.
R Avoid changing the wheel on uphill and down-
hill slopes. 282
Changing a wheelWheels and tires

R
Before raising the vehicle, secure it from roll-
ing away by applying the parking brake and
inserting wheel chocks. Do not disengage the parking brake while the vehicle is raised.
R The jack must be placed on a firm, flat and
non-slip surface. On a loose surface, a large,
flat, load-bearing underlay must be used. On a slippery surface, a non-slip underlay must be
used, e.g. rubber mats.
R Do not use wooden blocks or similar objects
as a jack underlay. Otherwise, the jack will not
be able to achieve its load-bearing capacity
due to the restricted height.
R Make sure that the distance between the
underside of the tires and the ground does not
exceed 1.2 in (3 cm).
R Do not place your hands or feet under the
raised vehicle.
R Do not lie under the vehicle.
R Do not start the engine when the vehicle is
raised.
R Do not open or close a door or the trunk lid
when the vehicle is raised.
R Make sure that no persons are present in the
vehicle when the vehicle is raised.
Vehicles with hub caps: the hub cap covers
the wheel bolts. Before you can unscrew the
wheel bolts, you must remove the hub cap. X
To remove: take socket0044and lug wrench
0087 from the vehicle tool kit (Y page 249).
X Position socket 0044on hub cap 0043.
X Position lug wrench 0087on socket 0044.
X Using lug wrench 0087, turn hub cap0043coun-
ter-clockwise and remove it.
X To install: before installing, check hub cap 0043
and the wheel area for soiling and clean if
necessary.
X Put hub cap 0043in position and turn until it is in
the right position. X
Position socket 0044on hub cap 0043.
X Attach lug wrench 0087to socket 0044and
tighten hub cap 0043.
The tightening torque must be
18 lb-ft (25 Nm).
i Note
that the hub cap should be tightened
to the specified torque of 18 lb-ft (25 Nm).
Mercedes-Benz recommends that you have
the hub cap installed at a qualified specialist
workshop. X
Using lug wrench 0087, loosen the bolts on the
wheel you wish to change by about one full
turn. Do not unscrew the bolts completely. The jacking point is centered between the front
and rear wheel arches (arrow). Changing a wheel
283Wheels and tires Z

X
Position jack 0083at jacking point 0085. X
Make sure that the base of the jack is posi-
tioned directly under jacking point 0085.
X Turn crank 0084clockwise until jack 0083sits
completely on jacking point 0085and the base
of the jack lies evenly on the ground.
X Turn crank 0084until the tire is raised a maxi-
mum of 1.2 in (3 cm) off the ground.
Removing a wheel !
AMG ceramic high performance composite
brake system:
When detaching or attaching the wheel, the
wheel rim may hit against the ceramic brake
disc and damage it.
Proceed with caution and seek the assistance of a second person.
! Do not place wheel bolts in sand or on a dirty
surface. The bolt and wheel hub threads could
otherwise be damaged when you screw them in.
When mounting/removing wheels, and for as
long as the wheels are removed, avoid applying any external force on the brake disks. This could
impair the level of comfort when braking. X
Unscrew the uppermost wheel bolt com-
pletely.
X Screw alignment bolt 0043into the thread
instead of the wheel bolt.
X Unscrew the remaining wheel bolts fully.
X Remove the wheel.
Mounting a new wheel G
WARNING
Oiled or greased wheel bolts or damaged
wheel bolts/hub threads can cause the wheel bolts to come loose. As a result, you could
lose a wheel while driving. There is a risk of
accident.
Never oil or grease wheel bolts. In the event ofdamage to the threads, contact a qualified
specialist workshop immediately. Have the
damaged wheel bolts or hub threads
replaced/renewed. Do not continue driving. G
WARNING
If you tighten the wheel bolts or wheel nuts
when the vehicle is raised, the jack could tip
over. There is a risk of injury.
Only tighten the wheel bolts or wheel nuts
when the vehicle is on the ground.
Always pay attention to the instructions and
safety notes in the "Changing a wheel" section
(Y page 281).
Only use wheel bolts that have been designed
for the wheel and the vehicle. For safety rea-
sons, Mercedes-Benz recommends that you
only use wheel bolts which have been approved for Mercedes-Benz vehicles and the respective
wheel.
! AMG ceramic high performance composite
brake system:
When detaching or attaching the wheel, the
wheel rim may hit against the ceramic brake
disc and damage it.
Proceed with caution and seek the assistance
of a second person.
! To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt. 284
Changing a wheelWheels and tires

0043
Wheel bolt
X Clean the wheel and wheel hub contact sur-
faces. X
Slide the wheel to be mounted onto the align-
ment bolt and push it on. X
Tighten the wheel bolts until they are finger-
tight.
X Unscrew the alignment bolt.
X Tighten the last wheel bolt until it is finger-
tight. Lowering the vehicle G
WARNING
The wheels could work loose if the wheel nuts and bolts are not tightened to the specified
tightening torque. There is a risk of accident.
Have the tightening torque immediately
checked at a qualified specialist workshop
after a wheel is changed.
X Turn the crank of the jack counter-clockwise
until the vehicle is once again standing firmly
on the ground.
X Place the jack to one side. X
Tighten the wheel bolts evenly in a crosswise
pattern in the sequence indicated (0043 to0083).
The specified tightening torque is 133 lb-ft
(180 Nm).
X Turn the jack back to its initial position.
X Stow the jack and the rest of the vehicle tools
in the trunk again.
X Check the tire pressure of the newly mounted
wheel and adjust it if necessary.
Observe the recommended tire pressure
(Y page 266).
When you are driving with the emergency spare
wheel mounted, the tire pressure monitor can-
not function reliably. Only restart the tire pres-
sure monitor when the defective wheel has been replaced with a new wheel. All wheels mounted
must be equipped with functioning sensors. Wheel and tire combinations
You can obtain information regarding permitted wheel/tire combinations at a qualified special-
ist workshop. Wheel and tire combinations
285Wheels and tires Z

!
For safety reasons, Mercedes-Benz recom-
mends that you only use tires and wheels
which have been approved by Mercedes-Benz specifically for your vehicle.
These tires have been specially adapted for
use with the control systems, such as ABS or
ESP ®
, and are marked as follows:
R MO = Mercedes-Benz Original
R MOE = Mercedes-Benz Original Extended
(tires featuring run-flat characteristics)
R MO1 = Mercedes-Benz Original (only cer-
tain AMG tires)
Mercedes-Benz Original Extended tires may
only be used on wheels that have been spe-
cifically approved by Mercedes-Benz.
Only use tires, wheels or accessories tested
and approved by Mercedes-Benz. Certain
characteristics, e.g. handling, vehicle noise
emissions or fuel consumption, may other-
wise be adversely affected. In addition, when
driving with a load, tire dimension variations
could cause the tires to come into contact
with the bodywork and axle components. This
could result in damage to the tires or the vehi- cle.
Mercedes-Benz accepts no liability for dam-
age resulting from the use of tires, wheels or
accessories other than those tested and
approved.
Information on tires, wheels and approved
combinations can be obtained from any quali-fied specialist workshop.
! Retreaded tires are neither tested nor rec-
ommended by Mercedes-Benz, since previ-
ous damage cannot always be detected on
retreaded tires. As a result, Mercedes-Benz
cannot guarantee vehicle safety if retreaded
tires are mounted. Do not mount used tires if
you have no information about their previous
usage.
The recommended pressures for various oper-
ating conditions can be found: R on the Tire and Loading Information placard
on the B-pillar on the driver's side
R in the tire pressure table in the fuel filler flap
Observe the notes on recommended tire pres-
sures under various operating conditions
(Y page 266).
Check tire pressures regularly, and only when
the tires are cold. Comply with the maintenance recommendations of the tire manufacturer in
the vehicle document wallet.
Notes on equipping the vehicle:
R Always mount tires of the same size across an
axle (left/right)
R Always mount the same type of tires on all
wheels at a given time (summer tires, winter
tires)
Exception: it is permissible to install a differ-
ent type or make in the event of a flat tire. 286
Wheel and tire combinationsWheels and tires