2019 MERCEDES-BENZ AMG GT ROADSTER engine

running an enclosed space without adequate
ventilation.
Certain engine systems are designed to keep
the level of poisonous components in exhaust
fumes within legal limits.
These systems only work at peak efficiency if
they are serviced exactly in accordance with the manufacturer's specifications. Always have
work on the engine carried out at a qualified
specialist workshop. Mercedes-Benz recom-
mends that you use an authorized Mercedes-
Benz Center for this purpose. In particular, work
relevant to safety or on safety-related systems
must be carried out at a qualified specialist
workshop.
The engine settings must not be changed under
any circumstances. Furthermore, all specific
service work must be carried out at regular
intervals and in accordance with the Mercedes- Benz service requirements.
You can obtain current information concerning
the servicing of your vehicle at any time from a
qualified specialist workshop. This could be an
overview of the maintenance work or any addi-
tional maintenance work, for example. Braking
Important safety notes G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients !
On long and steep gradients, you must
reduce the load on the brakes by shifting to a
lower gear in good time. This allows you to
take advantage of the engine's braking effect.
This helps you to avoid overheating the
brakes and wearing them out excessively.
When you take advantage of engine braking, a drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause damage to the drive train. This type of damage
is not covered by the Mercedes-Benz war-
ranty.
Heavy and light loads G
WARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance.132
Driving tipsDriving and parking

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

Driving on wet roads
Hydroplaning If water has accumulated to a certain depth on
the road surface, there is a danger of hydro-
planing occurring, even if:
R you drive at low speeds
R the tires have adequate tread depth
For this reason, in the event of heavy rain or in
conditions in which hydroplaning may occur,
you must drive in the following manner:
R lower your speed
R avoid ruts
R avoid sudden steering movements
R brake carefully
Driving on flooded roads !
Do not drive through flooded areas. Check
the depth of any water before driving through
it. Drive slowly through standing water. Oth-
erwise, water could enter the vehicle interior
or engine compartment. It can then damage
the engine's or automatic transmission's
electronic components. It can also be sucked
in by the engine's air intake connection and
cause engine damage. Winter driving
G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface. G
DANGER
If the exhaust pipe is blocked or adequate
ventilation is not possible, poisonous gases
such as carbon monoxide (CO) may enter the vehicle. This is the case, e.g. if the vehicle
becomes trapped in snow. There is a risk of
fatal injury. If you leave the engine or the auxiliary heating
running, make sure the exhaust pipe and area
around the vehicle are clear of snow. To
ensure an adequate supply of fresh air, open a window on the side of the vehicle that is not
facing into the wind.
Have your vehicle winter-proofed at a qualified
specialist workshop at the onset of winter.
Drive particularly carefully on slippery road sur- faces. Avoid sudden acceleration, steering and
braking maneuvers. Do not use cruise control.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X Shift the transmission to position 005C.
The outside temperature indicator is not
designed to serve as an ice-warning device and
is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay.
Indicated temperatures just above the freezing
point do not guarantee that the road surface is
free of ice. The road may still be icy, especially in wooded areas or on bridges. The vehicle could
skid if you fail to adapt your driving style. Always
adapt your driving style and drive at a speed to
suit the prevailing weather conditions.
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Further information on driving with snow chains (Y page 265).
Further information on driving with summer
tires (Y page 265).
Observe the notes in the "Winter operation" sec-
tion (Y page 265). Driving systems
Cruise control
General notes Cruise control maintains a constant road speed
for you. It brakes automatically in order to avoid
exceeding the set speed. Change into a lower
gear in good time on long and steep downhill
gradients. This is especially important if the
vehicle is laden. By doing so, you will make use of the braking effect of the engine. This relieves
the load on the brake system and prevents the 134
Driving syste
msDriving and parking

Setting a speed
Keep in mind that it may take a brief moment
until the vehicle has accelerated or braked to
the speed set.
X Press the cruise control lever up 0043for a
higher speed or down 0044for a lower speed.
X To adjust the set speed in 1 mph incre-
ments (1 km/h increments):
briefly press
the cruise control lever up 0043or down 0044to
the pressure point.
Every time the cruise control lever is pressed
up 0043 or down 0044the last speed stored is
increased or reduced.
X To adjust the set speed in 5 mph incre-
ments
(10 km/h increments): briefly press
the cruise control lever up 0043or down 0044
beyond the pressure point.
Every time the cruise control lever is pressed
up 0043 or down 0044the last speed stored is
increased or reduced.
i Cruise control is not deactivated if you
depress the accelerator pedal. If you acceler-
ate to overtake, cruise control adjusts the
vehicle's speed to the last speed stored after
you have finished overtaking.
Deactivating cruise control There are several ways to deactivate cruise con-
trol:
X Briefly press the cruise control lever for-
wards 0043.
or
X Brake.
Cruise control is automatically deactivated
under the following conditions:
R the electric parking brake is applied.
R you are driving slower than 20 mph
(30 km/h).
R if ESP ®
intervenes or you deactivate ESP ®
.
R you shift the transmission to position 005C
while driving.
If cruise control is deactivated, a warning tone
sounds. You will see the Cruise Control Off Cruise Control Off
message in the multifunction display for approx-
imately five seconds.
i When you switch off the engine, the last
speed stored is cleared. Active Distance Assist DISTRONIC
General notes Active Distance Assist DISTRONIC regulates the
speed and automatically helps you maintain the
distance from the vehicle detected in front.
Vehicles are detected with the aid of the radar
sensor system. Active Distance Assist
DISTRONIC brakes automatically so that the set
speed is not exceeded.
Change into a lower gear in good time on long
and steep downhill gradients. This is especially
important if the vehicle is laden. By doing so, you will make use of the braking effect of the engine.
This relieves the load on the brake system and
prevents the brakes from overheating and wear- ing too quickly.
If Active Distance Assist DISTRONIC detects
that there is a risk of a collision with the vehicle
in front, you will be warned visually and audibly.
Active Distance Assist DISTRONIC cannot pre-
vent a collision without your intervention. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the
instrument cluster. Brake immediately in order
to increase the distance to the vehicle in front or take evasive action provided it is safe to do so. 136
Driving systemsDriving and parking

Do not use Active Distance Assist DISTRONIC:
R In road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads
R on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
R when there is poor visibility, e.g. due to fog,
heavy rain or snow
Active Distance Assist DISTRONIC may not
detect narrow vehicles driving in front, e.g.
motorcycles, or vehicles driving in a staggered
formation.
In particular, the detection of obstacles can be
impaired if:
R There is dirt on the sensors or anything else
covering the sensors
R There is snow or heavy rain
R There is interference by other radar sources
R There are strong radar reflections, for exam-
ple, in parking garages
If Active Distance Assist DISTRONIC no longer
detects a vehicle in front, Distance Pilot
DISTRONIC may unexpectedly accelerate to the
speed stored.
This speed may:
R be too high if you are driving in a turning lane
or an exit lane
R be so high in the right lane that you pass vehi-
cles driving on the left (in countries where
they drive on the right)
R be so high in the left lane that you pass vehi-
cles driving on the right (right-hand drive
countries)
If there is a change of drivers, advise the new
driver of the speed stored. Cruise control lever 0043
Activates or increases speed
0044 Activates or reduces speed
0087 Deactivates Active Distance Assist
DISTRONIC
0085 Activates at the current speed or last stored
speed
0083 Sets a specified minimum distance
Activating Active Distance Assist
DISTRONIC Activation conditions
To activate Active Distance Assist DISTRONIC,
the following conditions must be fulfilled:
R the engine must be started. It may take up to
two minutes of driving before Active Distance Assist DISTRONIC is ready for use.
R the electric parking brake must be released.
R ESP ®
must be active, but not intervening.
R the transmission must be in position 005B.
R the driver's door must be closed when you
shift from 005Dto005B or your seat belt must be
fastened.
R the front-passenger door and rear doors must
be closed. 138
Driving systemsDriving an
d parking

Driving with Active Distance Assist
DISTRONIC Pulling away and driving
X
If you want to pull away with Active Dis-
tance Assist DISTRONIC: remove your foot
from the brake pedal.
X Briefly pull cruise control lever 0043towards
you.
or
X Accelerate briefly.
Your vehicle pulls away and adapts its speed
to that of the vehicle in front. If no vehicle is
detected in front, your vehicle accelerates to
the set speed.
i The vehicle can also pull away when it is
facing an unidentified obstacle or is driving on
a different line from another vehicle. The vehi-
cle then brakes automatically. There is a risk
of an accident. Be ready to brake at all times.
If there is no vehicle in front, Active Distance
Assist DISTRONIC operates in the same way as
cruise control.
If Active Distance Assist DISTRONIC detects a
slower-moving vehicle in front, it brakes your
vehicle. In this way, the distance you have selec- ted is maintained.
If Active Distance Assist DISTRONIC detects a
faster-moving vehicle in front, it increases the
driving speed. However, the vehicle is only
accelerated up to the speed you have stored.
Selecting the drive program Active Distance Assist DISTRONIC supports a
sporty driving style when you have selected the
S or S+ drive program. Acceleration behind the
vehicle in front or to the set speed is then notice- ably more dynamic. When you select the Cdrive
program, the vehicle accelerates more gently. This setting is recommended in stop-and-start
traffic.
Additional information on selecting the drive
program (Y
page 116).
Changing lanes If you change to the overtaking lane, Active Dis-
tance Assist DISTRONIC helps you if:
R you are driving at a speed greater than
45 mph (70 km/h)
R you switch on the appropriate turn signal
R Active Distance Assist DISTRONIC does not
currently detect a danger of collision
If these conditions are fulfilled, your vehicle is
accelerated. Acceleration will be interrupted if
changing lanes takes too long or if the distance
between your vehicle and the vehicle in front
becomes too small.
i When you change lanes, Active Distance
Assist DISTRONIC monitors the left lane.
Stopping G
WARNING
If you leave the driver's seat when the vehicle is only being braked by Active Distance Assist
DISTRONIC, it could roll away:
R if there is a malfunction in the system or in
the voltage supply
R if Active Distance Assist DISTRONIC is
deactivated using the cruise control lever,
for example by a vehicle occupant or from
outside the vehicle
R if the electrical system in the engine com-
partment, the battery or the fuses are tam-
pered with
R if the battery is disconnected
R if the vehicle is accelerated, e.g. by a vehi-
cle occupant
There is a risk of an accident.
Always deactivate Active Distance Assist
DISTRONIC and secure the vehicle against
rolling away before you leave it.
Further information about deactivating Active
Distance Assist DISTRONIC (Y page 142).
If Active Distance Assist DISTRONIC detects
that the vehicle in front is stopping, it brakes
your vehicle until it is stationary. 140
Driving syste
msDriving and parking

Once your vehicle is stationary, it remains sta-
tionary and you do not need to depress the
brake.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
i Depending on the specified minimum dis-
tance, your vehicle will come to a standstill at
a sufficient distance behind the vehicle in
front. The specified minimum distance is set
using the control on the cruise control lever.
The electric parking brake is applied automati-
cally if Active Distance Assist DISTRONIC is
active when the vehicle is stationary and:
R the driver's seat belt is not fastened and the
driver's door is open
R the engine is switched off, unless it is auto-
matically switched off by the ECO start/stop
function
R a system malfunction occurs
R the power supply is insufficient
If a malfunction occurs, the transmission may
also shift to position 005Dautomatically.
Setting a speed X
Press the cruise control lever up 0043for a
higher speed or down 0044for a lower speed.
X To adjust the set speed in 1 mph incre-
ments (1 km/h increments):
briefly press
the cruise control lever up 0043or down 0044to
the pressure point.
Every time the cruise control lever is pressed
up 0043 or down 0044the last speed stored is
increased or reduced.
X To adjust the set speed in 5 mph incre-
ments (10 km/h increments): briefly pressthe cruise control lever up
0043or down 0044
beyond the pressure point.
Every time the cruise control lever is pressed
up 0043 or down 0044, the last speed stored is
increased or reduced.
i If you accelerate to overtake, Active Dis-
tance Assist DISTRONIC adjusts the vehicle's
speed to the last speed stored after you have
finished overtaking.
Setting a specified minimum distance You can set the specified minimum distance for
Active Distance Assist DISTRONIC by varying
the time span between one and two seconds.
This determines the distance that Active Dis-
tance Assist DISTRONIC is to maintain from the
vehicle in front, depending on the road speed.
You can see this distance in the multifunction
display (Y page 142).
i Make sure that you maintain the minimum
distance to the vehicle in front as required by law. Adjust the distance to the vehicle in front
if necessary. X
To increase: turn control0044in direction 0087.
Active Distance Assist DISTRONIC then main- tains a greater distance between your vehicleand the vehicle in front.
X To decrease: turn control0044in direction 0043.
Active Distance Assist DISTRONIC then main- tains a shorter distance between your vehicle
and the vehicle in front. Driving systems
141Driving and parking Z

Deactivating Active Distance Assist
DISTRONIC There are several ways to deactivate Active Dis-
tance Assist DISTRONIC:
X Briefly press the cruise control lever for-
wards 0043.
or X Brake, unless the vehicle is stationary.
When you deactivate Active Distance Assist
DISTRONIC, the Active Distance Assist Active Distance Assist
Off
Off message appears on the multifunction dis-
play for approximately five seconds.
i The last speed stored remains stored until
you switch off the engine.
i Active Distance Assist DISTRONIC is not
deactivated if you depress the accelerator
pedal.
Active Distance Assist DISTRONIC is automati-
cally deactivated if: R you engage the electric parking brake or if the
vehicle is automatically secured with the elec-
tric parking brake
R ESP ®
intervenes or you deactivate ESP ®
R the transmission is in position 005D,005Eor005C
R you pull the cruise control lever towards you
in order to pull away and the front-passenger door or one of the rear doors is open
R the vehicle is skidding
If Active Distance Assist DISTRONIC is deacti-
vated, you will hear a warning tone. You will see
the Active Distance Assist Off
Active Distance Assist Off message
on the multifunction display for approximately
five seconds. Displays in the instrument cluster Displays in the speedometer
If Active Distance Assist DISTRONIC detects a
vehicle in front, the segments between speed of
vehicle in front 0043to stored speed 0044light up.
i For design reasons, the speed displayed on
the speedometer may differ slightly from the
speed set for Active Distance Assist
DISTRONIC.
Display when Active Distance Assist
DISTRONIC is deactivated
On the on-board computer, you can select the
assistance graphics display. 0043
Vehicle in front, if detected
0044 Distance indicator, current distance to the
vehicle in front
0087 Specified minimum distance to the vehicle
in front; adjustable
0085 Your vehicle
X Select the Assistance Graphic Assistance Graphic function
using the on-board computer (Y page 167).142
Driving syste
msDriving and parking