spare wheel MERCEDES-BENZ SL ROADSTER 2018 Owner's Manual

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:
RSnow chains may not be mounted on all
wheel/tire combinations. Permissible wheel-
tire combinations (
Ypage 308).
ROnly 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.
RLocal regulations may restrict the use of snow
chains. Observe the appropriate regulations if
you wish to mount snow chains.
RDo not exceed the maximum permissible
speed of 30 mph (50 km/h).
ROn vehicles with Active Body Control (ABC), if
snow chains have been installed, you must
drive at a raised vehicle level (
Ypage 163).
You may wish to deactivate ESP®when pulling
away with snow chains installed (Ypage 65).
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
GWARNING
Underinflated or overinflated tires pose the
following risks:
Rthe tires may burst, especially as the load
and vehicle speed increase.
Rthe tires may wear excessively and/or
unevenly, which may greatly impair tire
traction.
Rthe 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:
Rmonthly, at least
Rif the load changes
Rbefore beginning a long journey
Runder 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
:Recommended tire pressures
The Tire and Loading Information placard is on
the B-pillar on the driver's side (
Ypage 295).
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.
288Tire pressure
Wheels and tires

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:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
Rif 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:
Ron the Tire and Loading Information placard
on the B-pillar on the driver's side
Rin the tire pressure table on the inside of the
fuel filler flap
Underinflated or overinflated tires
Underinflated tires
GWARNING
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:
Roverheat, leading to tire defects
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on fuel consumption
Overinflated tires
GWARNING
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:
Rincrease the braking distance
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on ride comfort
Rbe more susceptible to damage
Maximum tire pressures
: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 (
Ypage 288).
iThe actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
290Tire pressure
Wheels and tires

Checking the tire pressures
Important safety notes
The tire pressure monitor does not warn you of:
Rincorrectly set tire pressure
Rsudden loss of tire pressure, e.g. from a for-
eign object that has penetrated the tire
Observe the notes on tire pressure
(
Ypage 288).
Information on air pressure for the tires on your
vehicle can be found:
Ron the vehicle's Tire and Loading Information placard on the B-pillar
Ron the tire pressure table in the fuel filler flap
Rin the "Tire pressure" section
Checking tire pressures manually
To determine and set the correct tire pressure,
proceed as follows:
XRemove the valve cap of the tire that is to be
checked.
XPress the tire pressure gauge securely onto
the valve.
XRead the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table(
Ypage 288).
XIf the tire pressure is too low, increase the tire
pressure to the recommended value.
XIf 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.
XScrew the valve cap onto the valve.
XRepeat 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
Serv.
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 (
Ypage 292).
Important safety notes
GWARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure rec-
ommended 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 Infor-
mation 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 pres-
sure 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 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 stop-
ping ability.
Please note that the TPMS is not a substitute
for proper tire maintenance, and it is the driv-
Tire pressure291
Wheels and tires
Z

Definition of termsfor tire san dloading
Tire pl ycomposition an dmaterial used
Describes th enumber of plie sor th enumber of
layer sof rubber-coated fabric in th etire tread
and sidewall .These are mad eof steel, nylon ,
polyester and other materials.
Ba r
Metric uni tfo rtire pressure. 14.503 8pounds
per square inch (psi) and 10 0kilopascals (kPa)
are th eequivalen tof 1bar .
DOT (Department of Transportation)
DOT-marke dtires fulfill th erequirements of th e
U S Departmen tof Transportation .
Normal occupant weigh t
The number of occupantsfo rwhic hth evehicle
is designed multiplie dby 68 kilogram s(15 0lbs) .
Unifor mTire Quality Grading Standard s
Auniform standard to grade th equalit yof tires
wit hregard sto tread quality, tire traction and
temperature characteristics .The qualit ygrad-
in g assessmen tis mad eby th emanufacturer
followin gspecification sfrom th eU.S. govern -
ment. The ratings are molded into th esidewall of
th etire.
Recommended tire pressure s
The recommended tire pressure applies to th e
tires mounted at th efactory.
The Tir eand Loadin gInformation placard con-
tain sth erecommended tire pressures fo rcold
tires on
afu
ll yloaded vehicle and fo rth emaxi-
mum permissible vehicle speed.
The tire pressure table contain sth erecommen -
ded pressures fo rcold tires fo rvarious operat -
in gconditions, i.e. differin gload and speed con-
ditions.
Increased vehicle weigh tdu eto optiona l
equipment
The combine dweight of all standard and
optional equipmen tavailable fo rth evehicle,
regardles sof whether it is actually installed on
th evehicle or not.
Ri m
Thi sis th epar tof th ewhee lon whic hth etire is
mounted.
GAW R(Gross Axle Weight Rating)
The GAW Ris th emaximum gross axl eweight
rating. The actual load on an axl emus tnever
exceed th egross axl eweight rating. The gross
axl eweight ratin gcan be found on th evehicle
identification plat eon th eB-pilla ron the driver's
side.
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 including fuel, tools, the spare wheel,
accessories installed, occupants, luggage and
the drawbar noseweight, if applicable. The gross
vehicle weight must not exceed the gross vehi-
cle wei
ght rating GVWR as specified on the vehi-
cle identification plate on the B-pillar on the
driver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the weight of the
vehicle including all accessories, occupants,
fuel, luggage and the drawbar noseweight, 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:
Rthe curb weight of the vehicle
Rthe weight of the accessories
Rthe load limit
Rthe 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 kilopascal s(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 capacity
more precisely.
302All about wheels and tires
Wheels and tires

XClean the wheel and wheel hub contact sur-
faces.
XSlide the wheel to bemounted onto the align-
ment boltand push iton.
XTighten the wheel bolts unt ilthey are finger-
tight.
XUnscrew the alignment bolt.
XTighten the last wheel boltuntil it is finger-
tight.
Lowering the vehicle
GWAR NING
The wheels could work loose ifthe wheel nuts
and bolts are not tightened to the specifie d
tightening torque. There isa risk of acc ident.
Have the tightening torque immediately
checked at a qualified specialist workshop
after a wheel ischanged.
XTurn the crank of the jack counter-clock wise
unt ilthe veh icle isonce again standing firmly
on the ground.
XPlace the jack to one side.
XTighten the wheel bolts evenly ina crosswise
pattern inthe sequence indicated (: toA). The specified tightening torque is
96lb-ft
(1 30 Nm) .
XTurn the jack back to its initial position.
XStow the jack and the rest of the vehicle tools
in the trunk again.
XMercedes-AMG vehicles and vehicles
with AMG equipment: insert the cover into
the outer sill.
XCheck the tire pressure of the ne wlymounted
wheel and adjust it if necessary.
Observe the recommended tire pressure
(
Ypage 288).
Vehicles with a tire pressure controlsys-
tem: all installed wheels must beequipped with
functioning sensors.
When you are driving with the emergency spare
wheel mounte d,the tire pressure monitor can-
not function reliably. Only restart the tire pres-
sure monitor when the defective wheel has been
replaced with a new wheel.
All mounted wheels must beequipped with func-
tioning sensors for the tire pressure monitor.
Wheel and tire combinations
You can ask for information regarding permitted
wheel/tire co mbinations at an authorized
Mercedes-Benz Center.
!For safety reasons, Mercedes-Benz recom-
mends that you only use tires and wheels
which have been approved by Mercedes-Benz
specifically for your vehicle.
These tires have been specially adapted for
use with the control systems, such as ABS or
ESP
®, and are marked as follows:
RMO = Mercedes-Benz Original
RMOE = Mercedes-Benz Original Extended
(t ires featuring run-flat characteristics)
RMO1 = Mercedes-Benz Original (only cer-
tain AMG tires)
Mercedes-Benz Original Extended tires may
only beused on wheels that have been spe-
cifically approved by Mercedes-Benz.
Only use tires, wheels or accessories tested
and approved by Mercedes-Benz. Certain
characteristics, e.g. handling, vehicle noise
emissions or fuel consumption, may other-
wise be adverselyaffected. In addition, when
driving with a load, tire dimension variations
308Wheel and tire combinations
Wheels and tires