2019 MERCEDES-BENZ AMG GT ROADSTER width

Observe the following rules when driving on salt-
treated roads:
R In order to prevent any salt build-up, apply the
brakes occasionally while paying attention to
the traffic conditions.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead.
Servicing the brakes !
The brake fluid level may be too low, if:
R if the red brake warning lamp lights up in
the instrument cluster and
R you hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately. Consult a qualified specialist workshop to
arrange this.
All checks and maintenance work on the brake
system must be carried out at a qualified spe-
cialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the functional-
ity of your brakes at regular intervals.
Information on BAS (Brake Assist) (Y page 59).
For safety reasons, Mercedes-Benz recom-
mends only installing the following brake disks
and brake pads/linings:
R brake disks that have been approved by
Mercedes-Benz
R brake pads/linings that have been approved
by Mercedes-Benz or that are of an equivalent
standard of quality
Other brake disks or brake pads/linings can
compromise the safety of your vehicle.
Always replace all brake disks and brake pads/
linings on an axle at the same time. Always
install new brake pads/linings when replacing
brake disks.
The vehicle is equipped with lightweight brake
disks to which the wheel assembly with rim and threaded connection is matched. The use of brake disks other than those
approved by Mercedes-Benz can change the
track width and is subject to approval, if appli-
cable.
Shock-type loads when handling the brake
discs, such as when changing wheels, can lead
to a reduction in comfort when driving with light-
weight brake discs. Avoid shock-type loads on
the lightweight brake disks, particularly on the
brake plate.
Mercedes-Benz recommends that you only use
brake fluid that has been specially approved for your vehicle by Mercedes-Benz, or which corre-
sponds to an equivalent quality standard. Brake fluid which has not been approved for
Mercedes-Benz vehicles or which is not of an
equivalent quality could affect your vehicle's
operating safety.
AMG high-performance and ceramic
brakes The AMG brake systems are designed for heavy
loads. This may lead to noise when braking. This
will depend on:
R Speed
R Braking force
R Environmental conditions, such as tempera-
ture and humidity
The wear of individual components of the brake system, such as the brake pads/linings or brake
discs, depends on the individual driving style
and operating conditions.
For this reason, it is impossible to state a mile-
age that will be valid under all circumstances. An aggressive driving style will lead to high wear.
You can obtain more information on this from a qualified specialist workshop.
New and replaced brake pads and discs only
reach their optimum braking effect after several
hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal.
Keep this in mind, and adapt your driving and
braking accordingly during this break-in period.
Excessive heavy braking results in correspond-
ingly high brake wear. Observe the brake wear
warning lamp in the instrument cluster and note
any brake status messages in the multifunction
display. Especially for high performance driving,
it is important to maintain and have the brake
system checked regularly. Driving tips
133Driving and parking Z

Narrow vehicles
Active Distance Assist DISTRONIC has not yet
detected the vehicle in front on the edge of the
road because of its narrow width. The distance
to the vehicle in front will be too short.
Obstructions and stationary vehicles Active Distance Assist DISTRONIC does not
brake for obstacles or stationary vehicles. If, for
example, the detected vehicle turns a corner
and an obstacle or stationary vehicle is revealed, Active Distance Assist DISTRONIC will not brake
for them.
Crossing vehicles Active Distance Assist DISTRONIC may mistak-
enly detect vehicles that are crossing your lane. Activating Active Distance Assist DISTRONIC at,
for example, a traffic light with crossing traffic
could cause your vehicle to pull away at the
wrong time. HOLD
General notes The HOLD function can assist the driver in the
following situations:
R when pulling away, especially on steep slopes
R when maneuvering on steep slopes
R when waiting in traffic
The vehicle is kept stationary without the driver having to depress the brake pedal.
The braking effect is canceled and the HOLD
function deactivated when you depress the
accelerator pedal to pull away.
Important safety notes G
WARNING
If the vehicle is only braked using the HOLD
function, the vehicle may roll away in the fol-
lowing situations when you leave the vehicle:
R if there is a malfunction in the system or in
the voltage supply
R if the HOLD function is deactivated by
depressing the accelerator pedal or brake
pedal, e.g. by a vehicle occupant
R if the electrical system in the engine com-
partment, the battery or the fuses are tam-
pered with or the battery is disconnected
There is a risk of an accident.
Always deactivate the HOLD function and
secure the vehicle against rolling away before
you leave it.
! When Active Distance Assist DISTRONIC or
the HOLD function is activated, the vehicle
brakes automatically in certain situations. 144
Driving systemsDriving an
d parking

Use the guidelines only for orientation.
Approach objects no further than the bottom-
most guideline. 0043
Yellow guide line at a distance of approx-
imately 13 ft (4.0 m) from the rear of the
vehicle
0044 White guide line without steering input –
vehicle width including the exterior mirrors
(static)
0087 Yellow guide line for the vehicle width
including the exterior mirrors, at the current
steering wheel angle (dynamic)
0085 Yellow lane marking the course the tires will
take at the current steering wheel angle
(dynamic) 0083
Yellow guide line at a distance of approx-
imately 3 ft (1.0 m) from the rear of the vehi-
cle
0084 Vehicle center axle (marker assistance)
006B Bumper
006C Red guide line at a distance of approximately
12 in (0.30 m) from the rear of the vehicle
The guide lines are shown when the transmis-
sion is in position 005E.
The distance specifications only apply to
objects that are at ground level. 0043
Front warning display
0044 Additional measurement operational readi-
ness indicator for Parking Assist
PARKTRONIC
0087 Rear warning display
Vehicles with Parking Assist PARKTRONIC:
when Parking Assist PARKTRONIC is opera-
tional (Y page 149), additional measurement
operational readiness indicator 0044appears in
the multimedia system display. If the Parking
Assist PARKTRONIC warning displays are active
or light up, warning displays 0043and 0087are also
active or light up correspondingly in the multi-
media system display.
"Reverse parking" function Backing up straight into a parking space
without steering input
0043
White guide line without steering input –
vehicle width including the exterior mirrors
(static)
0044 Yellow guide line for the vehicle width
including the exterior mirrors, at the current
steering wheel angle (dynamic) 152
Driving systemsDriving and parking

0087
Yellow guide line at a distance of approx-
imately 3 ft (1.0 m) from the rear of the vehi-
cle
0085 Red guide line at a distance of approximately
12 in (0.30 m) from the rear of the vehicle
X Make sure that the rear view camera is
switched on (Y page 151).
The lane and the guide lines are shown.
X With the help of white guide line 0043, check
whether the vehicle will fit into the parking
space.
X Using white guide line 0043as a guide, carefully
back up until you reach the end position.
Red guide line 0085is then at the end of parking
space. The vehicle is almost parallel in the
parking space.
Reverse perpendicular parking with steer- ing input 0043
Parking space marking
0044 Yellow guide line for the vehicle width
including the exterior mirrors, at the current
steering wheel angle (dynamic)
X Drive past the parking space and bring the
vehicle to a standstill.
X Make sure that the rear view camera is
switched on (Y page 151).
The lane and the guide lines are shown.
X While the vehicle is at a standstill, turn the
steering wheel in the direction of the parking space until yellow guide line 0044reaches park-
ing space marking 0043.
X Maintain the steering input and reverse care-
fully. 0043
Yellow guide line for the vehicle width
including the exterior mirrors, at the current
steering wheel angle (dynamic)
X Stop the vehicle when it is almost exactly in
front of the parking space.
The white lane should be as close to parallel
with the parking space marking as possible. 0043
White guide line at the current steering input
0044 Parking space marking
X Turn the steering wheel to the center position
while the vehicle is stationary. 0043
Red guide line at a distance of approximately
12 in (0.30 m) from the rear of the vehicle
0044 White guide line without steering input
0087 End of parking space Driving systems
153Driving and parking 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

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

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