2014 MERCEDES-BENZ SL-CLASS ROADSTER Owners Manual

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 :
Recommended tire pressures
The Tire and Loading Information placard is
on the B-pillar on the driver's side
(Y page 253).
The Tire and Loading Information placard
contains 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. Example: tire pressure table for all tires permitted
for this vehicle by the factory The tire pressure table contains the
recommended pressures for cold tires for
various operating conditions, i.e. differing
load and speed conditions.
Example: tire pressure table with tire dimensions
If a tire size precedes a tire pressure, the tire
pressure information following is only valid
for that tire size. The load conditions "partially
laden" and "fully laden" are defined in the
table for different numbers of occupants and
amounts of luggage. The actual number of
seats may differ.
Some tire pressure tables show only the rim
diameters instead of the full tire size, e.g.
R18. The rim diameter is part of the tire size
and can be found on the tire sidewall
(Y
page 257).
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. Tire pressure
247Wheels and tires Z

i
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 sudden loss of pressure.
For more information, contact a qualified
specialist 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,
contact 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
pressure 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 electronic tire pressure monitoring
system, the tire pressure can be checked
using 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
pressures when the tires are cold.
The tires are cold:
R
if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has been driven for less 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 on the inside of
the fuel filler flap Underinflated or overinflated tires
Underinflation G
WARNING
Tires with pressure that is too low can
overheat and burst as a consequence. In
addition, they also suffer from excessive and/
or 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 low in all the
tires, including the spare wheel. 248
Tire pressureWheels and tires

Underinflated tires may:
R
overheat, leading to tire defects
R have an adverse effect on handling
characteristics
R wear quickly and unevenly
R have an adverse effect on fuel consumption
Overinflation 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 have an adverse effect on handling
characteristics
R wear quickly and unevenly
R have an adverse effect on ride comfort
R be more susceptible to damage
Maximum tire pressures :
Example: maximum permissible tire
pressure
Never exceed the maximum permissible tire
inflation pressure. Always observe the
recommended tire pressure for your vehicle when adjusting the tire pressure
(Y
page 246).
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. Checking the tire pressures
Important safety notes Observe the notes on tire pressure
(Y
page 246).
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 on the tire pressure label on the fuel filler
flap
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 gauge securely onto
the valve.
X Read the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard (Y page 246).
X If the tire pressure is too low, increase it to
the recommended value.
X If the tire pressure is too high, release air
by pressing down the metal pin in the valve.
Use the tip of a pen, for example. Then,
check the tire pressure again using the tire
pressure gauge.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires. Tire pressure
249Wheels and tires Z

Tire pressure monitor
General notes If a tire pressure monitor is installed, the
vehicle's wheels have sensors that monitor
the tire pressures in all four tires. The tire
pressure monitor warns you if the pressure
drops in one or more of the tires. The tire
pressure monitor only functions if the correct
sensors are installed on 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. Example: current tire pressure display
For information on the message display, refer
to the "Checking the tire pressure
electronically" section (Y page 251).
Important safety notes G
WARNING
Each tire, including the spare (if provided),
should be checked at least once a month
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
pressure 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 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
pressure telltale when one or more of your tires are significantly underinflated.
Accordingly, when the low tire pressure
telltale illuminates, you should stop and check
your tires as soon as possible, and inflate
them to the proper pressure. Driving on a
significantly underinflated 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 responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale.
USA only:
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate if the
system is not operating properly. The TPMS
malfunction indicator is combined with the
low tire pressure telltale. When the system
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
vehicle is started as long as the malfunction
exists.
When the malfunction indicator is illuminated,
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
incompatible 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 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 246). Note that the correct tire
pressure for the current operating situation 250
Tire pressureWheels and tires

must first be taught-in to the tire pressure
monitor. If there is a substantial loss of
pressure, the warning threshold for the
warning message is aligned to the reference
values taught-in. Restart the tire pressure
monitor after adjusting the pressure of the
cold tires (Y page 252). The current
pressures 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 246).
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 maneuvers.
The tire pressure monitor has a yellow
warning lamp in the instrument cluster for
indicating a pressure loss or 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 malfunctioning.
R if the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
i In addition to the warning lamp, a
message appears in the multifunction
display.
Further information can be found on
(Y page 174).
If the tire pressure monitor is malfunctioning,
it may take more than ten minutes for the tire
pressure warning lamp to inform you of the
malfunction by 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
measured at a gas station with a pressure
gauge. 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 gauge 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
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle.
Checking the tire pressure
electronically X
Make sure that the SmartKey is in position
2in the ignition lock (Y page 121).
X Press the =or; button on the
steering wheel to select the Service
Service
menu.
X Press the 9or: button to select
Tire Pressure Tire Pressure .
X Press the abutton.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle has been parked for over
20 minutes, the Tire pressure will be Tire pressure will be
displayed after driving a few
displayed after driving a few
minutes minutes message appears.
After a teach-in process, the tire pressure
monitor 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 Pressure Tire Pressure
Monitor Active
Monitor Active display message is shown
instead of the tire pressure display. The tire
pressures are already being monitored. Tire pressure
251Wheels and tires Z

Tire pressure monitor warning
messages
If the tire pressure monitor detects a pressure
loss in one or more tires, a warning message
is shown in the multifunction display and the
yellow tire pressure monitor warning lamp
comes on.
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 and must be corrected at the next
opportunity.
R If the Check
Check Tires Tiresmessage appears in the
multifunction display, the tire pressure in
one or more tires has dropped significantly
and the tires must be checked.
R If the Warning Tire Malfunction
Warning Tire Malfunction
appears in the multifunction display, the
tire pressure in one or more tires has
dropped suddenly and the tires must be
checked.
Observe the instructions and safety notes in
the display messages in the "Tires" section
(Y page 174).
i 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 pressures
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 currently set tire pressures as the
reference values for monitoring. In most
cases, the tire pressure monitor will
automatically detect the new reference
values after you have changed the tire
pressure. However, you can also define
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
recommended for the corresponding
driving situation on the Tire and Loading
Information placard on the driver's side
B-pillar (Y page 246).
Additional tire pressure values for different
loads can also be found on the tire pressure
table on the inside of the fuel filler flap
(Y page 246).
X Make sure that the tire pressure is correct
on all four wheels.
X Make sure that the SmartKey is in position
2in the ignition lock.
X Press the =or; button on the
steering wheel to select the Service
Service
menu.
X Press the 9or: button to select
Tire Pressure Tire Pressure .
X Press the abutton.
The multifunction display shows the
current tire pressure for the individual tires
or the Tire pressure will be
Tire pressure will be
displayed after driving a few displayed after driving a few
minutes minutes message.
X Press the :button.
The Use Current Pressures as New
Use Current Pressures as New
Reference Values
Reference Values message appears in
the multifunction display.
If you wish to confirm the restart:
X Press the abutton.
The Tire Pressure Monitor Tire Pressure Monitor
Restarted
Restarted message appears in 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
pressures are then accepted as reference
values and monitored.
If you wish to cancel the restart:
X Press the %button.
The tire pressure values stored at the last
restart will continue to be monitored. 252
Tire pressureWheels and tires

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 maximum permissible number
of occupants and the maximum
permissible vehicle load. It also contains
details of the tire sizes and
corresponding pressures for tires
installed at the factory.
(2) The vehicle identification plate is on the B-pillar on the driver's side. The vehicle
identification 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 information 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). Never
exceed the maximum load or the
maximum gross axle weight rating for the
front or rear axle. :
B-pillar, driver's side Maximum permissible gross vehicle
weight rating
X
Specification for maximum gross vehicle
weight :is listed in 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 gross vehicle weight rating is
vehicle-specific and may differ from that in
the illustration. You can find the valid
maximum permissible gross vehicle weight
rating for your vehicle on the Tire and
Loading Information placard. Loading the vehicle
253Wheels and tires Z

Number of seats
Maximum number of seats
:indicates the
maximum number of occupants allowed to
travel in the vehicle. This information can be
found on the Tire and Loading Information
placard.
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
pursuant 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 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
available amount of cargo and luggage load
capacity. For example, if the "XXX" amount
equals 1,400 lbs and there will be five
150 lbs passengers in your vehicle, the
amount of available cargo and luggage load
capacity is 650 lbs (1,400 – 750 (5 x 150)
= 650 lbs).
X Step 5: Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely exceed
the available cargo and luggage load
capacity calculated in step 4. Example: steps 1 to 3
The following table shows examples on how
to calculate total and cargo load capacities
with varying seating configurations and
number and size of occupants. The following
examples use a maximum load of 1,500 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 Information placard
(Y page 253).
The higher the weight of all the occupants, the
smaller the maximum load for luggage.
Step 1 Example 1 Example 2
Combined
maximum
weight of
occupants
and cargo
(data from the
Tire and
Loading
Information
placard)
1500 lbs
(680 kg) 1500 lbs
(680 kg)254
Loading the vehicleWheels and tires