2019 MERCEDES-BENZ AMG GT ROADSTER Owner's Manual

The tire pressure must be corrected when the
opportunity arises.
R If the Check Tires
Check Tires message appears in the
multifunction display, the tire pressure in at
least one tire has dropped significantly. The
tires must be checked.
R If the Warning Warning Tire
TireMalfunction
Malfunction message
appears in the multifunction display, the tire
pressure in at least one tire has dropped sud-
denly. The tires must be checked.
Observe the instructions and safety notes in the display messages in the "Tires" section
(Y page 192).
If the wheel positions on the vehicle are rotated,
the tire pressures may be displayed for the
wrong positions for a short time. This is rectified after a few minutes of driving, and the tire pres-
sures are displayed for the correct positions.
Restarting the tire pressure monitor When you restart the tire pressure monitor, all
existing warning messages are deleted and the
warning lamps go out. The monitor uses the cur-
rently set tire pressures as the reference values for monitoring. In most cases, the tire pressure
monitor will automatically detect the new refer-
ence values after you have changed the tire
pressure. However, you can also set reference
values manually as described here. The tire
pressure monitor then monitors the new tire
pressure values.
X Set the tire pressure to the value recommen-
ded for the corresponding driving situation on the Tire and Loading Information placard on
the driver's side B-pillar (Y page 266).
You can find more tire pressure values for
various operating conditions in the tire pres-
sure table inside the fuel filler flap
(Y page 266).
X Make sure that the tire pressure is correct on
all four wheels.
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
Service menu.
X Press 0076.
X Press 0063or0064 to select Tire Pres‐ Tire Pres‐
sure
sure. X
Press 0076.
The current tire pressure for each wheel or
the Tire pressure will be displayed Tire pressure will be displayed
after driving a few minutes after driving a few minutes message
will be displayed in the multifunction display.
X Press 0064.
The Use
Use Current
Current Pressures
Pressures as
asNew
New Ref‐
Ref‐
erence
erence Values
Valuesmessage appears in the mul-
tifunction display.
If you wish to confirm the restart: X Press 0076.
The Tire
Tire Press.
Press. Monitor
Monitor Restarted
Restarted mes-
sage appears on the multifunction display.
After driving for a few minutes, the system
checks whether the current tire pressures are
within the specified range. The new tire pres- sures are then accepted as reference values
and monitored.
If you wish to cancel the restart: X Press 0038.
The tire pressure values stored at the last
restart will continue to be monitored. Loading the vehicle
Instruction labels for tires and loads
G
WARNING
Overloaded tires can overheat, causing a
blowout. Overloaded tires can also impair the steering and driving characteristics and lead
to brake failure. There is a risk of accident.
Observe the load rating of the tires. The load
rating must be at least half of the GAWR of
your vehicle. Never overload the tires by
exceeding the maximum load.
Two instruction labels on your vehicle show the maximum possible load.
(1) The Tire and Loading Information placard is on the B-pillar on the driver's side. The Tire
and Loading Information placard shows the
permissible number of vehicle occupants
and the maximum permissible load of the
vehicle. It also contains details of the tire Loading the vehicle
271Wheels and tires Z

sizes and corresponding pressures for tires
mounted at the factory.
(2) The vehicle identification plate is on the B- pillar on the driver's side. The vehicle iden-
tification plate informs you of the gross
vehicle weight rating. It is made up of the
vehicle weight, all vehicle occupants, the
fuel and the cargo. You can also find infor-
mation about the maximum gross axle
weight rating on the front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried by one axle (front or rear axle). Do not exceed
the maximum gross vehicle weight or the
maximum gross axle weight rating for the
front or rear axle. 0043
B-pillar, driver's side Maximum permissible mass.
X
Maximum permissible gross vehicle
weight 0043is listed on the Tire and Loading
Information placard: "The combined weight of occupants and cargo should never exceed
XXX kilograms or XXX lbs."
The gross weight of all vehicle occupants, load
and luggage must not exceed the specified
value. i
The specifications shown on the Tire and
Loading Information placard in the illustration
are examples. The maximum permissible load is vehicle-specific and may deviate from the
data shown here. The maximum permissible
load that applies for your vehicle can be foundon your vehicle's Tire and Loading Informa-
tion placard. Number of seats
Maximum number of seats
0043indicates the
maximum number of occupants allowed to
travel in the vehicle. This information can be
found on the Tire and Loading Information plac-
ard.
i The specifications shown on the Tire and
Loading Information placard in the illustration
are examples. The number of seats is vehicle- specific and can differ from the details shown.
The number of seats in your vehicle can be
found on the Tire and Loading Information
placard. Determining the correct load limit
Step-by-step instructions The following steps have been developed as
required of all manufacturers under Title 49,
Code of U.S. Federal Regulations, Part 575 pur-
suant to the "National Traffic and Motor Vehicle
Safety Act of 1966".
X Step 1: Locate the statement "The combined
weight of occupants and cargo should never 272
Loading the vehicleWheels and tires

exceed XXX kg or XXX lbs." on your vehicle’s
Tire and Loading Information placard.
X Step 2: Determine the combined weight of
the driver and passengers that will be riding in your vehicle.
X Step 3: Subtract the combined weight of the
driver and passengers from XXX kilograms or
XXX lbs.
X Step 4: The resulting figure equals the avail-
able amount of cargo and luggage load capa- city. For example, if the "XXX" amount equals
1400 lbs and there will be five 150-lb pas-
sengers in your vehicle, the amount of avail-
able cargo and luggage load capacity is
650 lbs (1400 - 750 (5 x 150) = 650 lbs).
X Step 5: Determine the combined weight of
luggage and cargo being loaded on the vehi-
cle. That weight may not safely exceed the
available cargo and luggage load capacity cal- culated in step 4. Example: steps 1 to 3
The following table shows examples of how to calculate total and cargo load capacities with varying
seating configurations and different numbers and weights of vehicle occupants. The following
examples use a load limit of 1500 lbs (680 kg). This is for illustration purposes only.Make sure
you are using the actual load limit for your vehicle stated on your vehicle's Tire and Loading Infor-
mation placard (Y page 271).
The higher the weight of all the vehicle occupants, the smaller the maximum load for luggage.
Step 1 Example 1 Example 2 Example 3
Combined maximum
weight of vehicle occu-
pants and load (data
from the Tire and Load-
ing Information plac-
ard)
1500 lbs (680 kg) 1500 lbs (680 kg) 1500 lbs (680 kg)
Step 2
Example 1 Example 2 Example 3
Number of people in
the vehicle (driver and
occupants)
5 3 1
Distribution of the
occupants
Front: 2
Rear: 3 Front: 1
Rear: 2 Front: 1Loading the vehicle
273Wheels and tires Z

Example 1 Example 2 Example 3
Weight of the occu-
pants
Occupant 1: 150 lbs
(68 kg)
Occupant 2: 180 lbs
(82 kg)
Occupant 3: 160 lbs
(73 kg)
Occupant 4: 140 lbs
(63 kg)
Occupant 5: 120 lbs
(54 kg) Occupant 1: 200 lbs
(91 kg)
Occupant 2: 190 lbs
(86 kg)
Occupant 3: 150 lbs
(68 kg) Occupant 1: 150 lbs
(68 kg)
Gross weight of all
occupants
750 lbs (340 kg) 540 lbs (245 kg) 150 lbs (68 kg)
Step 3
Example 1 Example 2 Example 3
Permissible load (maxi-
mum gross vehicle
weight rating from the
Tire and Loading Infor-
mation placard minus
the gross weight of all
occupants)
1500 lbs (680 kg)
00F8
750 lbs (340 kg) =
750 lbs (340 kg) 1500 lbs (680 kg)
00F8
540 lbs (245 kg)
=960 lbs (435 kg) 1500 lbs (680 kg)
00F8
150 lbs (68 kg) =
1350 lbs (612 kg) Vehicle identification plate
Even if you have calculated the total load care-
fully, you should still make sure that the gross
vehicle weight rating and the gross axle weight
rating are not exceeded. Details can be found on
the vehicle identification plate on the B-pillar on
the driver's side of the vehicle (Y page 271).
Gross vehicle weight: the gross weight of the
vehicle, all vehicle occupants, load and trailer
load/noseweight (if applicable) must not
exceed the gross vehicle weight rating.
Gross Axle Weight Rating (GAWR): the maxi-
mum permissible load that can be carried by one axle (front or rear axle).
To ensure that your vehicle does not exceed thegross vehicle weight and maximum gross axle
weight rating, have your loaded vehicle (includ-
ing driver, vehicle occupants, load and full trailer
load if applicable) weighed on a suitable vehicle weighbridge. All about wheels and tires
Uniform Tire Quality Grading Stand-
ards
Overview of Tire Quality Grading Stand- ards Uniform Tire Quality Grading Standards are U.S.
government specifications. Their purpose is to
provide drivers with uniform reliable information on tire performance data. Tire manufacturers
have to grade tires using three performance fac- 274
All about wheels and tiresWheels and tires

tors:
0043tread wear grade, 0044traction grade and
0087 temperature grade. These regulations do not
apply to Canada. Nevertheless, all tires sold in
North America are provided with the corre-
sponding quality grading markings on the side-
wall of the tire.
Quality grades can be found, where applicable,
on the tire sidewall between tread shoulder and
maximum section width.
Example:
R Treadwear grade: 200
R Traction grade: AA
R Temperature grade: A
All passenger car tires must conform to the stat-
utory safety requirements in addition to these
grades.
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Treadwear The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified U.S.
government course. For example, a tire graded
150 would wear one and one-half times as well
on the government course as a tire graded 100.
The relative performance of tires depends upon the actual conditions of their use, however, and
may depart significantly from the norm due to
variations in driving habits, service practices
and differences in road characteristics and cli-
mate.
Traction G
WARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor- nering, hydroplaning, or peak traction char-
acteristics.
! Avoid wheelspin. This can lead to damage to
the drive train.
The traction grades – from highest to lowest –
are AA, A, B and C. Those grades represent the
tire's ability to stop on wet pavement as meas-
ured under controlled conditions on specified
government test surfaces of asphalt and con- crete. A tire marked C may have poor traction
performance.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road surfaces.
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Mercedes-Benz recommends a minimum tread
depth of 00CFin (4 mm) on all four winter tires.
Observe the legally required minimum tire tread
depth (Y page 264). Winter tires can reduce the
braking distance on snow-covered surfaces in
comparison with summer tires. The braking dis-
tance is still much further than on surfaces that
are not icy or covered with snow. Take appro-
priate care when driving.
Further information on winter tires (M+S tires)
(Y page 265).
Temperature G
WARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, or excessive loading, either separately or
in combination, can cause excessive heat
build-up and possible tire failure.
The temperature grades are A (the highest), B,
and C, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions
on a specified indoor laboratory test wheel. Sus- tained high temperature can cause the material
of the tire to degenerate and reduce tire life, and excessive temperature can lead to sudden tire
failure. The grade C corresponds to a level of
performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety
Standard No. 109. Grades B and A represent
higher levels of performance on the laboratory
test wheel than the minimum required by law. All about
wheels and tires
275Wheels and tires Z

Tire labeling
Overview 0043
Uniform Tire Quality Grading Standard
(Y page 279)
0044 DOT, Tire Identification Number
(Ypage 278)
0087 Maximum tire load (Y page 278)
0085 Maximum tire pressure (Y page 268)
0083 Manufacturer
0084 Tire material (Y page 279)
006B Tire size designation, load-bearing capacity
and speed rating (Y page 276)
006C Load index (Y page 278)
006D Tire name
The markings described above are on the tire in
addition to the tire name (sales designation) and the manufacturer's name.
i Tire data is vehicle-specific and may deviate
from the data in the example.
Tire size designation, load-bearing
capacity and speed rating G
WARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the tire load rating and speed rating required for
your vehicle. 0043
Tire width
0044 Nominal aspect ratio in %
0087 Tire code
0085 Rim diameter
0083 Load bearing index
0084 Speed rating
General: depending on the manufacturer's
standards, the size imprinted in the tire wall may not contain any letters or may contain one letterthat precedes the size description.
If there is no letter preceding the size descrip-
tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description: these are
passenger vehicle tires according to U.S. man-
ufacturing standards.
If "LT" precedes the size description: these are
light truck tires according to U.S. manufacturing standards.
If "T" precedes the size description: compact
emergency wheels with high tire pressure that
are only designed for temporary use in an emer-
gency.
Tire width: tire width0043shows the nominal tire
width in millimeters.
Height-width ratio: aspect ratio0044is the size
ratio between the tire height and tire width and is shown in percent. The aspect ratio is calcula-ted by dividing the tire width by the tire height.
Tire code: tire code0087specifies the tire type.
"R" represents radial tires; "D" represents diag-
onal tires; "B" represents diagonal radial tires.
Optionally, tires with a maximum design speed
of over 149 mph (240 km/h) may have "ZR" in 276
All about
wheels and tiresWheels and tires

the size description, depending on the manu-
facturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter0085is the diameter
of the bead seat, not the diameter of the rim
flange. The rim diameter is specified in
inches (in).
Load-bearing index: load-bearing index0083is a
numerical code that specifies the maximum
load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum permissible
load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on
the driver's side (Y page 271).
Example:
Load-bearing index 91 indicates a maximum
load of 1,356 lb (615 kg) that the tires can bear.
For further information on the maximum tire
load in kilograms and lbs, see (Y page 278).
For further information on the load bearing
index, see "Load index" (Y page 278).
Speed rating: speed rating0084specifies the
approved maximum speed of the tire.
i Tire data is vehicle-specific and may deviate
from the data in the example.
Regardless of the speed rating, always observe
the speed limits. Drive carefully and adapt your
driving style to the traffic conditions.
Summer tires Index Speed rating
Q up to 100 mph (160 km/h)
R up to 106 mph (170 km/h)
S up to 112 mph (180 km/h)
T up to 118 mph (190 km/h)
H up to 130 mph (210 km/h)
V up to 149 mph (240 km/h)
W up to 168 mph (270 km/h)
Y up to 186 mph (300 km/h)
ZR...Y up to 186 mph (300 km/h)
ZR...(..Y) over 186 mph (300 km/h)
ZR over 149 mph (240 km/h) R
Optionally, tires with a maximum design
speed of over 149 mph (240 km/h) may have "ZR" in the size description, depending on the
manufacturer (e.g. 245/40 ZR18).
The service specification is made up of load-
bearing index 0083and speed rating 0084.
R If the size description of your tire includes
"ZR" and there are no service specifications,
ask the tire manufacturer in order to find out
the maximum design speed.
If a service specification is available, the max-
imum speed is limited according to the speed rating in the service specification. Example:
245/40 ZR18 97 Y.In this example, "97 Y" is
the service specification. The letter "Y" rep-
resents the speed rating. The maximum
design speed of the tire is limited to 186 mph (300 km/h).
R The size description for all tires with maxi-
mum design speeds of over 186 mph
(300 km/h) must include "ZR", andthe ser-
vice specification must be given in brackets.
Example: 275/40 ZR 18 (99 Y). Speed rating
"(Y)" indicates that the maximum design
speed of the tire is over 186 mph (300 km/h). To find out the maximum design speed, ask
the tire manufacturer.
All-weather tires and winter tires Index Speed rating
Q M+S
1 up to 100 mph (160 km/h)
T M+S
1 up to 118 mph (190 km/h)
H M+S
1 up to 130 mph (210 km/h)
V M+S
1 up to 149 mph (240 km/h)
i
Not all tires with the M+S marking provide
the driving characteristics of winter tires. In
addition to the M+S marking, winter tires also
have the 004Dsnowflake symbol on the tire
wall. Tires with this marking fulfill the require- ments of the Rubber Manufacturers Associa-
tion (RMA) and the Rubber Association of
Canada (RAC) regarding the tire traction on
snow. They have been especially developed
for driving on snow.
An electronic speed limiter prevents your vehi-
cle from exceeding a speed of 130 mph
(210 km/h).
1 Or M+S 004Dfor winter tires. All about wheels and tires
277Wheels and tires Z

The speed rating of tires mounted at the factory
may be higher than the maximum design speed permitted by the electronic speed limiter.
Make sure that your tires have the required
speed rating, e.g. when buying new tires. The
required speed rating for your vehicle can be
found in the "Tires" section (Y page 285).
Further information about reading tire data can
be obtained from any qualified specialist work-
shop.
Load index In addition to the load-bearing index, load
index
0043may also be imprinted on the sidewall
of the tire. You will find this after the letter that identifies the speed rating (Y page 276).
R If no specification is given: no text (as in the
example above), represents a standard load
(SL) tire
R XL or Extra Load: represents a reinforced tire
R Light Load: represents a light load tire
R C, D, E: represents a load range that depends
on the maximum load that the tire can carry at a certain pressure
i Tire data is vehicle-specific and may deviate
from the data in the example. Maximum load rating Maximum tire load
0043is the maximum permis-
sible weight for which the tire is approved.
Do not overload the tires by exceeding the
specified load limit. The maximum permissible
load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on
the driver's side (Y page 271).
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
DOT, Tire Identification Number (TIN) US tire regulations stipulate that every tire man-
ufacturer or retreader must imprint a TIN in or on the sidewall of each tire produced. The TIN is a unique identification number. The
TIN enables the tire manufacturers or retreaders to inform purchasers of recalls and other safety-
relevant matters. It makes it possible for the
purchaser to easily identify the affected tires.
The TIN is made up of manufacturer identifica-
tion code 0044, tire size 0087, tire type code 0085and
manufacturing date 0083.
DOT (Department of Transportation): tire
symbol 0043marks that the tire complies with the 278
All about wheels and tiresWheels and tires