2019 MERCEDES-BENZ AMG GT ROADSTER Owner's Manual

Important safety notes
G
WARNING
If wheels and tires of the wrong size are used, the wheel brakes or suspension components
may be damaged. There is a risk of an acci-
dent.
Always replace wheels and tires with those
that fulfill the specifications of the original
part.
When replacing wheels, make sure to use the
correct:
R designation
R model
When replacing tires, make sure to use the
correct:
R designation
R manufacturer
R model G
WARNING
A flat tire severely impairs the driving, steer-
ing and braking characteristics of the vehicle.
There is a risk of accident.
Tires without run-flat characteristics:
R do not drive with a flat tire.
R immediately replace the flat tire with your
emergency spare wheel or spare wheel, or
consult a qualified specialist workshop.
Tires with run-flat characteristics:
R pay attention to the information and warn-
ing notices on MOExtended tires (tires with
run-flat characteristics).
Accessories that are not approved for your vehi-
cle by Mercedes-Benz or are not being used cor- rectly can impair the operating safety.
Before purchasing and using non-approved
accessories, visit a qualified specialist work-
shop and inquire about:
R suitability
R legal stipulations
R factory recommendations Information on the sizes and types of wheels and
tires for your vehicle can be found under
"Wheel/tire combinations" (Y page 285).
Tire pressure information can be found:
R on the Tire and Loading Information placard
on the B-pillar on the driver's side
(Y page 271)
R in the tire pressure table in the fuel filler flap
(Y page 126)
R in the "Tire pressure" section Operation
Information on driving
Check the tire pressure when the vehicle is
heavily laden and adjust prior to a trip.
While driving, pay attention to vibrations, noises
and unusual handling characteristics, e.g. pull-
ing to one side. This may indicate that the
wheels or tires are damaged. If you suspect that a tire is defective, reduce your speed immedi-
ately. Stop the vehicle as soon as possible to
check the wheels and tires for damage. Hidden
tire damage could also be causing the unusual
handling characteristics. If you find no signs of
damage, have the tires and wheels checked at a
qualified specialist workshop.
When parking your vehicle, make sure that the
tires do not get deformed by the curb or other
obstacles. If they cannot be avoided, drive over obstacles such as curbs slowly and at an obtuse
angle. Otherwise, you may damage the wheels
or tires. Notes on high performance tires
G
WARNING
Due to the special tire tread in combination
with the optimized rubber compound, there is an increased risk of hydroplaning and skid-
ding on damp or wet road surfaces. In addi-
tion, tire traction is significantly reduced at
low outside temperatures and low tire-oper-
ating temperatures. There is a risk of an acci-
dent.
Activate ESP ®
and adapt your driving style. At
outside temperatures below 50 ‡(10 †), use
M+S tires. Operation
263Wheels and tires Z

i
Different driving styles may lead to high tire
wear and the tires may reach the minimum
tire tread depth after only a short time. Regular checking of wheels and tires
G
WARNING
Damaged tires can cause tire inflation pres-
sure loss. As a result, you could lose control of your vehicle. There is a risk of accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
Check wheels and tires for damage at least once a month. Check wheels and tires after driving
off-road or on rough roads. Damaged wheels
can cause a loss of tire pressure.
Pay particular attention to damage such as:
R Cuts in the tires
R Punctures in the tires
R Tears in the tires
R Bulges on tires
R Deformation or severe corrosion on wheels
Regularly check the tire tread depth and the
condition of the tread across the whole width of
all tires (Y page 264). If necessary, turn the
front wheels to full lock in order to inspect the
inner side of the tire surface.
All wheels must have a valve cap to protect the
valve against dirt and moisture. Do not mount
anything onto the valve other than the standard valve cap or other valve caps approved by
Mercedes-Benz for your vehicle. Do not use any other valve caps or systems, e.g. tire pressure
monitoring systems.
Regularly check the pressure of all the tires par- ticularly prior to long trips. Adjust the tire pres-
sure as necessary (Y page 266).
The service life of tires depends, among other
things, on the following factors:
R Driving style
R Tire pressure
R Distance covered Notes on tire tread
G
WARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water.
This means that on wet road surfaces, the risk of hydroplaning increases, in particular where speed is not adapted to suit the driving con-
ditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at differ-
ent locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
R Summer tires: 00CEin (3 mm)
R M+S tires: 00CFin (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached. Marking
0043shows where the bar indicator
(arrow) for tread wear is integrated into the tire
tread.
Treadwear indicators (TWI) are required by law. Six indicators are positioned on the tire tread.
They are visible once a tread depth of approx-
imately 00CDin (1.6 mm) has been reached. If this
is the case, the tire is so worn that it must be
replaced. Selecting, mounting and replacing
tires
R Only mount tires and wheels of the same type
and make. 264
OperationWheels and tires

Exception: it is permissible to mount a differ-
ent type or make in the event of a flat tire.
R Only mount tires of the correct size onto the
wheels.
R Break in new tires at moderate speeds for the
first 60 miles (100 km). The new tires only
reach their full performance after this dis-
tance.
R Do not drive with tires which have too little
tread depth. This significantly reduces the
traction on wet roads (hydroplaning).
R Replace the tires after six years at the latest,
regardless of wear. Winter operation
General notes
Have your vehicle winter-proofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Changing a wheel"
section (Y page 281). Driving with summer tires
At temperatures below 45 ‡ (+7 †), summer
tires lose elasticity and therefore traction and
braking power. Change the tires on your vehicle to M+S tire s. Using summer tires at very cold
temperatures could cause cracks to form,
thereby damaging the tires permanently.
Mercedes-Benz cannot accept responsibility for
this type of damage. M+S tires
G
WARNING
M+S tires with a tire tread depth of less than
00CF in (4 mm) are not suitable for use in winter
and do not provide sufficient traction. There is
a risk of an accident.
M+S tires with a tread depth of less than 00CFin
(4 mm) must be replaced immediately.
At temperatures below 45 ‡(+7 †), use winter
tires or all-season tires. Both types of tire are
identified by the M+S marking.
Only winter tires bearing the 004Dsnowflake
symbol in addition to the M+S marking provide the best possible grip in wintry road conditions.
Only these tires will allow driving safety systems
such as ABS and ESP ®
to function optimally in
winter. These tires have been developed specif-
ically for driving in snow.
Use M+S tires of the same make and tread on all wheels to maintain safe handling characteris-
tics.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
When you have mounted the M+S tires:
X Check the tire pressures (Y page 266).
X Restart the tire pressure monitor
(Y page 271). Snow chains
G
WARNING
If snow chains are installed to the front
wheels, they may drag against the vehicle
body or chassis components. This could
cause damage to the vehicle or the tires.
There is a risk of an accident.
To avoid hazardous situations:
R never install snow chains to the front
wheels
R always install snow chains in pairs to the
rear wheels.
For safety reasons, Mercedes-Benz recom-
mends that you only use snow chains that have been specially approved for your vehicle by
Mercedes-Benz, or are of a corresponding
standard of quality. For more information,
please contact a qualified specialist workshop.
If you intend to mount snow chains, please bear
the following points in mind:
R Snow chains may not be mounted on all
wheel/tire combinations. Permissible
wheel/tire combinations (Y page 285).
R Only use snow chains when driving on roads
completely covered by snow. Remove the
snow chains as soon as possible when you
come to a road that is not snow-covered. Winter operation
265Wheels and tires Z

R
Local regulations may restrict the use of snow
chains. Observe the appropriate regulations if you wish to mount snow chains.
R do not exceed the maximum permissible
speed of 31 mph (50 km/h).
You may wish to deactivate ESP ®
(Y page 63)
when pulling away with snow chains mounted.
You can thereby allow the wheels to spin in a
controlled manner, achieving an increased driv-
ing force (cutting action). Tire pressure
Tire pressure specifications
Important safety notes G
WARNING
Underinflated or overinflated tires pose the
following risks:
R the tires may burst, especially as the load
and vehicle speed increase.
R the tires may wear excessively and/or
unevenly, which may greatly impair tire
traction.
R the driving characteristics, as well as steer-
ing and braking, may be greatly impaired.
There is a risk of an accident.
Follow recommended tire inflation pressures
and check the pressure of all the tires includ-
ing the spare wheel:
R monthly, at least
R if the load changes
R before beginning a long journey
R under different operating conditions, e.g.
off-road driving
If necessary, correct the tire pressure.
The data on the Tire and Loading Information
placard and tire pressure table shown here are
examples. Tire pressure specifications are vehi- cle-specific and may deviate from the data
shown here. The tire pressure specifications
that are valid for your vehicle can be found on
the Tire and Loading Information placard and
tire pressure table on the vehicle. General notes The recommended tire pressures for the tires
mounted at the factory can be found on the
labels described here.
Further information on tire pressures can be
obtained at a qualified specialist workshop.
Tire and Loading Information placard 0043
Recommended tire pressures
The Tire and Loading Information placard is on
the B-pillar on the driver's side (Y page 271).
The Tire and Loading Information placard con-
tains the recommended tire pressures for cold
tires. The recommended tire pressures are valid for the maximum permissible load and up to the
maximum permissible vehicle speed.
Tire pressure table The tire pressure table is on the inside of the fuel
filler flap. It shows the tire pressure for all tires
permitted at the factory for this vehicle; see
illustration (example).
If a tire size precedes a tire pressure, the tire
pressure information following is only valid for
that tire size. 266
Tire pressureWheels and tires

If the tire pressures have been set to the lower
values for lighter loads and/or lower road
speeds, the pressures should be reset to the
higher values:
R if you want to drive with an increased load
and/or
R if you want to drive at higher road speeds
The tire pressures for increased loads and/or
higher road speeds, shown in the tire pressure
table, may have a negative effect on driving
comfort.
If the tire pressure is not set correctly, this can
lead to an excessive build-up of heat and a sud-
den loss of pressure.
For more information, contact a qualified spe-
cialist workshop. Important notes on tire pressure
G
WARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident. R Check the tire for foreign objects.
R Check whether the wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage, con-
tact a qualified specialist workshop. G
WARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded and malfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire pres- sure monitors keep the tire valve open. This
can also result in tire pressure loss. There is a
risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the tire
pressure. The outer appearance of a tire does
not permit any reliable conclusion about the tire pressure. On vehicles equipped with the elec-
tronic tire pressure monitor, the tire pressure
can be checked in the on-board computer.
The tire temperature and pressure increase
when the vehicle is in motion. This is dependent
on the driving speed and the load.
Therefore, you should only correct tire pres-
sures when the tires are cold.
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)
The tire temperature changes depending on the
outside temperature, the vehicle speed and the
tire load. If the tire temperature changes by
18 ‡ (10 †), the tire pressure changes by
approximately 10 kPa (0.1 bar/1.5 psi). Take
this into account when checking the pressure of
warm tires. Only correct the tire pressure if it is too low for the current operating conditions. If
you check the tire pressure when the tires are
warm, the resulting value will be higher than if
the tires were cold. This is normal. Do not
reduce the tire pressure to the value specified
for cold tires. The tire pressure would otherwise
be too low.
Observe the recommended tire pressures for
cold tires:
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
(Y page 126). Tire pressure
267Wheels and tires Z

Underinflated or overinflated tires
Underinflated tires G
WARNING
Tires with pressure that is too low can over-
heat and burst as a consequence. In addition, they also suffer from excessive and/or irreg-
ular wear, which can severely impair the brak- ing properties and the driving characteristics.There is a risk of an accident.
Avoid tire pressures that are too low in all the
tires, including the spare wheel.
Underinflated tires may:
R overheat, leading to tire defects
R adversely affect handling
R wear excessively and/or unevenly
R have an adverse effect on fuel consumption
Overinflated tires G
WARNING
Tires with excessively high pressure can burst
because they are damaged more easily by
road debris, potholes etc. In addition, they
also suffer from irregular wear, which can
severely impair the braking properties and the driving characteristics. There is a risk of an
accident.
Avoid tire pressures that are too high in all the
tires, including the spare wheel.
Overinflated tires may: R increase the braking distance
R adversely affect handling
R wear excessively and/or unevenly
R have an adverse effect on ride comfort
R be more susceptible to damage Maximum tire pressures 0043
Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure (Y page 266).
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration. Checking the tire pressures
Important safety notes Observe the notes on tire pressure
(Y
page 266).
Information on air pressure for the tires on your
vehicle can be found:
R on the vehicle's Tire and Loading Information
placard on the B-pillar
R in the tire pressure table in the fuel filler flap
(Y page 126)
R in the "Tire pressure" section
Checking tire pressures manually To determine and set the correct tire pressure,
proceed as follows:
X Remove the valve cap of the tire that is to be
checked.
X Press the tire pressure gage securely onto the
valve.
X Read the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table
(Y page 266). 268
Tire pressureWheels and tires

X
If the tire pressure is too low, increase the tire
pressure to the recommended value.
X If the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check the tire pressure again using the tire pressure
checker.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires. Tire pressure monitor
General notes If a tire pressure monitor is installed, the vehi-
cle's wheels have sensors that monitor the tire
pressures in all four tires. The tire pressure mon-
itor warns you if the pressure drops in one or
more of the tires. The tire pressure monitor only functions if the corresponding sensors are
installed in all wheels.
Information on tire pressures is displayed in the
multifunction display. After a few minutes of
driving, the current tire pressure of each tire is
shown in the Service
Service menu of the multifunction
display; see illustration (example). For information on the message display, refer to
the "Checking the tire pressure electronically"
section (Y page 270).
Important safety notes G
WARNING
Each tire, including the spare (if provided),
should be checked at least once every two
weeks when cold and inflated to the pressure recommended by the vehicle manufacturer
on the Tire and Loading Information placard on the driver's door B-pillar or the tire pres-
sure label on the inside of the fuel filler flap. If your vehicle has tires of a different size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,
when the low tire pressure telltale lights up,
you should stop and check your tires as soon
as possible, and inflate them to the proper
pressure. Driving on a significantly underin-
flated tire causes the tire to overheat and can
lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's handling and stopping ability. Please note that
the TPMS is not a substitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even if underinflation has not reached the level to
trigger illumination of the TPMS low tire pres-
sure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the sys-
tem detects a malfunction, the warning lamp
will flash for approximately a minute and then remain continuously illuminated. This
sequence will be repeated every time the vehi-
cle is started as long as the malfunction
exists. When the malfunction indicator is illu- minated, the system may not be able to detect
or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction telltale after replacing one
or more tires or wheels on your vehicle to Tire pressure
269Wheels and tires
Z

ensure that the replacement or alternate Tires
and wheels allow the TPMS to continue to
function properly.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
(Y page 266). Note that the correct tire pressure
for the current operating situation must first be taught-in to the tire pressure monitor. If a sub-
stantial loss of pressure occurs, the warning
threshold for the warning message is aligned tothe taught-in reference values. Restart the tire
pressure monitor after adjusting the pressure of
the cold tires (Y page 271). The current pres-
sures are saved as new reference values. As a
result, a warning message will appear if the tire pressure drops significantly.
The tire pressure monitor does not warn you of
an incorrectly set tire pressure. Observe the
notes on the recommended tire pressure
(Y page 266).
The tire pressure monitor is not able to warn you of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.
The tire pressure monitor has a yellow warning
lamp in the instrument cluster for indicating
pressure loss or a malfunction. Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitor is malfunctioning:
R if the warning lamp is lit continuously, the tire
pressure on one or more tires is significantly
too low. The tire pressure monitor is not mal-
functioning.
R if the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
(Y page 192).
It may take up to ten minutes for a malfunction
of the tire pressure monitor to be indicated. A
malfunction will be indicated by the tire pres-
sure warning lamp flashing for approximately
one minute and then remaining lit. When the
malfunction has been rectified, the tire pressure warning lamp goes out after a few minutes of
driving. The tire pressure values indicated by the on-
board computer may differ from those meas-
ured at a gas station with a pressure gage. The
tire pressures shown by the on-board computer
refer to those measured at sea level. At high
altitudes, the tire pressure values indicated by a pressure gage are higher than those shown by
the on-board computer. In this case, do not
reduce the tire pressures.
The operation of the tire pressure monitor can
be affected by interference from radio transmit-
ting equipment (e.g. radio headphones, two-way radios) that may be being operated in or near the vehicle.
Checking the tire pressure electroni-
cally X
Switch on the ignition (Y page 111).
X Press 00E2on the steering wheel to call up
the list of menus.
X Press 0063or0064 on the steering wheel to
select the Service Servicemenu.
X Press 0076.
X Press 0063or0064 to select Tire Pres‐
Tire Pres‐
sure
sure.
X Press 0076.
The current tire pressure of each tire is shown in the multifunction display.
If the vehicle was parked for longer than
20 minutes, the Tire pressure will be Tire pressure will be
displayed after driving a few minutes displayed after driving a few minutes
message appears.
After a teach-in process, the tire pressure mon-
itor automatically detects new wheels or new
sensors. As long as a clear allocation of the tire
pressure value to the individual wheels is not
possible, the Tire TirePressure Pressure Monitor
MonitorActive
Active
message is shown instead of the tire pressure
display. The tire pressures are already being
monitored.
Tire pressure monitor warning mes-
sages If the tire pressure monitor detects a pressure
loss in one or more tires, a warning message is
shown in the multifunction display. The yellow
tire pressure warning lamp then lights up.
R If the Please Correct Tire Pressure Please Correct Tire Pressure
message appears in the multifunction display,
the tire pressure in at least one tire is too low. 270
Tire pressureWheels and tires