578 OperationTires and wheelsGeneral:
Depending on the design standards used,
the tire size molded into the sidewall may
have no letter or a letter preceding the tire
size designation.
No letter preceding the size designation
(as illustrated above): Passenger car tire
based on European design standards.
Letter “P” preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter “LT” preceding the size designation:
Light Truck tire based on U.S. design
standards.
Letter “T” preceding the size designation:
Temporary spare tires which are high
pressure compact spares designed for
temporary emergency use only. Tire width
The tire width1 (
page 577) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (page 577) is the
dimensional relationship between tire
section height and section width and is
expressed in percentage. The aspect ratio
is arrived at by dividing section height by
section width.
Tire code
The tire code3 (
page 577) indicates
the tire construction type. The “R” stands
for radial tire type. Letter “D” means diag-
onal or bias ply construction; letter “B”
means belted-bias ply construction.
At the tire manufacturer’s option, any tire
with a speed capability above 149 mph
(240 km/h) can include a “ZR” in the size
designation (for example: 245/40 ZR 18).
For additional information, see “Tire speed
rating” (
page 579).Rim diameter
The rim diameter4 (
page 577) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating5 (page 577) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1 356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 582) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.
586 OperationTires and wheelsBar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least 3 hours or
driven no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.DOT (D
epartment o
f T
ransportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross A
xle W
eight R
ating)
The GAWR is the maximum permissible
axle weight. The gross vehicle weight on
each axle must never exceed the GAWR for
the front and rear axle indicated on the
certification label located on the driver’s
door B-pillar.
GVW (G
ross V
ehicle W
eight)
The GVW comprises the weight of the
vehicle including fuel, tools, spare wheel,
installed accessories, passengers and
cargo and, if applicable, trailer tongue
load. The GVW must never exceed the
GVWR indicated on the certification label
located on the driver’s door B-pillar.GVWR (G
ross V
ehicle W
eight R
ating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight of
the vehicle including all options, passen-
gers, fuel, and cargo and, if applicable,
trailer tongue load). It is indicated on certi-
fication label located on the driver’s door
B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kilopascals (kPa) to 1 psi; another
metric unit for air pressure is bars. There
are 100 kilopascals (kPa) to 1 bar.
Maximum load rating
The maximum load in kilograms and
pounds that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
total load limit and production options
weight.
591 Operation
Winter driving
Snow chainsSnow chains should only be driven on
snow-covered roads at speeds not to
exceed 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow.
Please observe the following guidelines
when using snow chains:
Use of snow chains is not permissible
with all wheel/tire combinations
(page 727).
Use snow chains in pairs and rear
wheels only. Follow the manufacturer’s
mounting instructions.
Only use snow chains that are
approved by Mercedes-Benz. Any
authorized Mercedes-Benz Center will
be glad to advise you on this subject.
Use of snow chains may be prohibited
depending on location. Always check
local and state laws before installing
snow chains.
Do not use snow chains on the spare
wheel (
page 730).
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Center.!
When driving with snow chains, always se-
lect the raised level of the level control system
ABC (page 461). Other settings may result in
damage to your vehicle.
!
Some tire sizes do not leave adequate clear-
ance for snow chains. To help avoid serious dam-
age to your vehicle or tires, make sure that the
use of snow chains is permissible as specified in
the “Technical data” section of this Operator’s
Manual, see “Rims and tires” (
page 727).
!
If snow chains are mounted to the front
wheels, they may scrape against the body or axle
components. The tires or the vehicle could be
damaged as a result.
i
All models except CL 63 AMG:
When driving with snow chains, you may wish to
switch off the ESP
® (page 72) before setting
the vehicle in motion. This will improve the
vehicle’s traction.
i
CL 63 AMG:
Do not switch off the ESP
® when driving in snow
or with snow chains mounted.
619 Practical hints
What to do if …?
Warning!
G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
vehicle placard or the tire inflation pressure
label. (If your vehicle has tires of a different
size than the size indicated on the vehicle
placard or the tire inflation pressure label,
you should determine the proper tire infla-
tion pressure for those tires).
As an added safety feature, your vehicle has
been equipped with a Advanced Tire Pres-
sure Monitoring System (Advanced TPMS)
that illuminates a low tire pressure telltale
when one or more of your tires is significant-
ly under-inflated. Accordingly, when the low
tire pressure telltale illuminates, you should
stop and check your tires as soon as possi-
ble, and inflate them to the proper pressure.
Driving on a significantly under-inflated tire
causes the tire to overheat and can lead to
tire failure.
Under-inflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the Advanced TPMS is not a sub-
stitute for proper tire maintenance, and it is
the driver’s responsibility to maintain cor-
rect tire pressure, even if under-inflation has
not reached the level to trigger illumination
of the Advanced TPMS low tire pressure
telltale.
USA only
Your vehicle has also been equipped with a
Advanced TPMS malfunction indicator to in-
dicate when the system is not operating
properly. The Advanced TPMS malfunction
indicator is combined with the low tire pres-
sure telltale. When the system detects a
malfunction, the telltale will flash for approx-
imately 1 minute and then remain continu-
ously illuminated. This sequence will
continue upon subsequent vehicle start-ups
as long as the malfunction exists. When the
malfunction indicator is illuminated, the sys-
tem may not be able to detect or signal low
tire pressure as intended.
Advanced TPMS malfunctions may occur for
a variety of reasons, including the installa-
tion of replacement or alternate tires or
wheels on the vehicle that prevent the Ad-
vanced TPMS from functioning properly. Al-
ways check the Advanced TPMS
malfunction telltale after replacing one or
more tires or wheels on your vehicle to en-
sure that the replacement or alternate tires
and wheels allow the Advanced TPMS to
continue to function properly.
679 Practical hints
What to do if …?
Display
Possible cause/consequence
Possible solution
Wheel Sensor(s)
Missing
One or more sensors malfunction (e.g. bat-
tery in one or more wheel sensor is empty).
One or more wheels without wheel sensors
mounted (e.g. spare tire).
No pressure value is shown on the multi-
function display for the tire in question.
Have the Advanced TPMS checked by an
authorized Mercedes-Benz Center.
Have the wheel sensors installed by an
authorized Mercedes-Benz Center.
The tire pressure for the respective tire is
shown in the multifunction display after a few
minutes driving.
Tire Pressure
Please Rectify
Advanced TPMS:
The pressure is too low in one or more tires.
Or the tire pressures of the individual
wheels differ too radically from one
another.
Check and adjust tire inflation pressure as
required (
page 575).
696 Practical hintsFlat tirePreparing the vehicle
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flasher
(page 397).
Turn the steering wheel so that the
front wheels are in a straight ahead
position.
Shift the automatic transmission to
park positionP.
Engage the electronic parking brake.
Turn off the engine.
Have any passenger exit the vehicle at
a safe distance from the roadway.
Vehicles with SmartKey: Remove the
SmartKey from the starter switch.
Vehicles with KEYLESS-GO*: Open the
driver’s door (this puts the starter
switch in position0, same as with the
SmartKey removed from the starter
switch). The driver’s door then can be
closed again.
Remove the KEYLESS-GO*
start/stop button from the starter
switch.
Mounting the spare wheel
i
Open the door only when conditions are safe
to do so.
Warning!
G
The dimensions of the spare wheel are dif-
ferent from those of the road wheels. As a
result, the vehicle handling characteristics
change when driving with a spare wheel
mounted. Adapt your driving style accord-
ingly.
The spare wheel is for temporary use only.
When driving with spare wheel mounted,
ensure proper tire inflation pressure and
do not exceed a vehicle speed
of 50 mph (80 km/h).
Contact the nearest Mercedes-Benz Center
as soon as possible to have the spare wheel
replaced with a regular road wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® when a spare
wheel is mounted.
697 Practical hints
Flat tire
Preparing the vehicle
Prepare the vehicle as described
(page 696).
Take vehicle tool kit and vehicle jack
out of trunk (
page 681).
Take the spare wheel and wheel bolts
out of the trunk (
page 683).Lifting the vehicle
Prevent the vehicle from rolling away
by blocking wheels with wheel chocks
or other sizeable objects.
One wheel chock is included with the
vehicle tool kit (
page 683).
When changing wheel on a level surface:
Place the wheel chock in front of and
another sizeable object behind the
wheel that is diagonally opposite to the
wheel being changed.
Always try lifting the vehicle using the jack
on a level surface. However, should cir-
cumstances require you to do so on a hill,
place the wheel chock and another size-
able object as follows:
Place the wheel chock and another
sizeable object on the downhill side
blocking both wheels on the side of the
vehicle not being worked on.
Warning!
G
The jack is designed exclusively for jacking
up the vehicle at the jack take-up brackets
built into both sides of the vehicle. To help
avoid personal injury, use the jack only to lift
the vehicle during a wheel change. Never
get beneath the vehicle while it is supported
by the jack. Keep hands and feet away from
the area under the lifted vehicle. Always en-
gage the electronic parking brake and block
wheels before raising vehicle with jack.
Do not disengage electronic parking brake
while the vehicle is raised. Be certain that
the jack is always vertical (plumb line) when
in use, especially on hills. Always try to use
the jack on level surface.
Make sure the jack arm is fully seated in the
jack take-up bracket. Always lower the vehi-
cle onto sufficient capacity jackstands be-
fore working under the vehicle.
699 Practical hints
Flat tire
Removing the wheel
1Alignment bolt
Unscrew upper-most wheel bolt and re-
move.
Replace this wheel bolt with alignment
bolt1 supplied in the tool kit.
Remove the remaining bolts.
Remove the wheel.Attaching the Minispare wheel
Warning!
G
Position the jack only on the jack take-up
brackets designed for this purpose.
If the jack is not properly positioned, the ve-
hicle may fall off the jack and cause serious
personal injury or damage to the vehicle.Warning!
G
The jack is intended only for lifting the
vehicle briefly for wheel changes. It is not
suited for performing maintenance work
under the vehicle.
Never start the engine when the vehicle
is raised.
Never lie down under the raised vehicle.
!
Do not place wheel bolts in sand or dirt. This
could result in damage to the bolt and wheel hub
threads.
Warning!
G
Always replace wheel bolts that are dam-
aged or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be re-
paired immediately. Do not continue to drive
under these circumstances! Contact an au-
thorized Mercedes-Benz Center or call
Roadside Assistance.
Incorrect wheel bolts or improperly tight-
ened wheel bolts can cause the wheel to
come off. This could cause an accident.
Make sure you are using the correct wheel
bolts.