342 Operation
Tires and wheels
Run Flat Indicator (Canada only)
While the vehicle is being driven, the Run
Flat Indicator monitors the set tire inflation
pressures by evaluating each wheel’s rota-
tional speed. This allows the system to de-
tect a significant loss of pressure in a tire.
If a wheel’s rotational speed changes due
to falling tire inflation pressure, you will
see a corresponding warning message in
the multifunction display.
The Run Flat Indicator may function in a re-
stricted manner or with a delay
if snow chains are mounted to the
vehicle
in presence of ice and snow
if you are driving on a loose surface
(e.g. sand or gravel)
if you are driving in a very sporty man-
ner (involving rapid acceleration or high
speeds in curves)
if you are driving with the roof loaded
(CLK coupe) or very heavy cargo
Warning!G
When the multifunction display shows the
message
Tire Pressure Check Tires,
one or more of your tires is significantly un-
derinflated. You should stop and check your
tires as soon as possible, and inflate them to
the proper tire inflation pressure as indicat-
ed on the vehicle’s Tire and Loading
Information placard or, if available, on the
tire inflation pressure label. Driving on a sig-
nificantly under-inflated tire causes the tire
to overheat and can lead to tire failure. Un-
derinflation also reduces fuel efficiency and
tire tread life, and may affect the vehicle’s
handling and stopping ability. Each tire, in-
cluding the spare, should be checked
monthly when cold and set to the recom-
mended tire inflation pressure as specified
on the Tire and Loading Information placard
on the driver’s door B-pillar (
page 334) or,
if available, on the tire inflation pressure la-
bel located on the inside of the fuel filler flap
(
page 320).
Warning!G
The Run Flat Indicator does not provide a
warning for wrongly selected tire inflation
pressures. Always adjust tire inflation pres-
sure according to the Tire and Loading
Information placard on the driver’s door
B-pillar (
page 334) or, if available, on the
tire inflation pressure label located on the
inside of the fuel filler flap (
page 320).
The Run Flat Indicator does not replace
regular checks of the tire inflation pressures
since a gradual pressure loss in more than
one tire cannot be detected by the Run Flat
Indicator.
The Run Flat Indicator is not able to issue a
warning due to a sudden dramatic loss of
tire inflation pressure (e.g. tire blowout
caused by a foreign object). In this case
bring the vehicle to a halt by carefully apply-
ing the brakes and avoiding abrupt steering
maneuvers.
345 Operation
Tires and wheels
Warning!G
Each tire, including the Minispare, should be
checked monthly when cold and inflated to
the inflation pressure recommended by the
vehicle manufacturer on the Tire and
Loading Information placard or, if available,
on the tire inflation pressure label. If your ve-
hicle has tires of a different size than the
size indicated on the Tire and Loading
Information placard or, if available, the tire
inflation pressure label, you should deter-
mine the proper tire inflation pressure for
those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly underinflated tire causes the tire to over-
heat and can lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’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.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately 1 minute
and then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the mal-
function 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
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.
iIf a condition causing the TPMS to malfunc-
tion develops, it may take up to 10 minutes
for the system to signal a malfunction using
the TPMS telltale flashing and illumination
sequence.
The telltale extinguishes after a few minutes
driving if the malfunction has been corrected.
iOperating radio transmission equipment
(e.g. wireless headsets, two-way radios) in or
near the vehicle could cause the TPMS to
malfunction.
349 Operation
Tires and wheels
1Uniform Quality Grading Standards
(
page 356)
2DOT, Tire Identification Number (TIN)
(
page 353)
3Maximum tire load (
page 354)
4Maximum tire inflation pressure
(
page 355)
5Manufacturer
6Tire ply material (
page 357)
7Tire size designation, load and speed
rating (
page 349)
8Load identification (
page 352)
9Tire nameTire size designation, load and speed
rating
1Tire width
2Aspect ratio in %
3Radial tire code
4Rim diameter
5Tire load rating
6Tire speed ratingGeneral:
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.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
For more information, see “Rims and tires”
(
page 482).
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
358 Operation
Tires and wheels
Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa) or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.Bar
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 (Department of Transportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross Axle Weight Rating)
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 Vehicle Weight)
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.
363 Operation
Winter driving
Block heater (Canada only)
The engine is equipped with a block
heater.
The electrical cable may be installed at an
authorized Mercedes-Benz Center.
Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not higher
than 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:
Using snow chains is not permissible
with all wheel/tire combinations
(
page 482).
Use snow chains in pairs and on 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 482).
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.!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 the use of
snow chains is permissible as specified in the
“Technical data” section of this Operator’s Man-
ual, see “Rims and tires” (
page 482).
!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.
iWhen driving with snow chains, you may
wish to deactivate the ESP® (page 94) before
setting the vehicle in motion. This will improve
the vehicle‘s traction.
CLK 63 AMG:
Do not switch off the ESP
® when driving in snow
or with snow chains mounted.
389 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
Tire and Loading Information placard on the
driver’s door B-pillar (
page 334) or, if
available, the tire inflation pressure label on
the inside of the fuel filler flap (
page 320).
If your vehicle has tires of a different size
than the size indicated on the Tire and
Loading Information placard or the tire
inflation pressure label, you should deter-
mine the proper tire inflation pressure for
those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly underinflated tire causes the tire to over-
heat and can lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’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.Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately 1 minute
and then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the mal-
function 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
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.
421 Practical hints
Where will I find...?
Where will I find...?
First aid kit
The first aid kit is located in the trunk on
the left side (CLK coupe) or on the right
side (CLK cabriolet), secured by a hook
and loop fastener.
Example CLK coupe
Loosen hook and loop fastener.
Remove first aid kit.Storage compartment underneath the
trunk floor
The TIREFIT kit (CLK 63 AMG only) or the
vehicle tool and the Minispare wheel are
located under the trunk floor.
1Handle
2Push handle
Raising: Pu s h i n h a n d l e1 in direction
of arrow2. The other side of
handle1 lifts up.
Take handle1 and lift up the trunk
floor cover.1Handle
3Upper trunk lip
Engage handle1 on upper trunk
lip3.
You can now access the TIREFIT kit
(CLK 63 AMG only) or the vehicle tool kit
and Minispare wheel.
Lowering: To disengage handle1 lift
up the trunk floor.
Disengage handle1 from upper trunk
lip3 and lower the trunk floor cover.
iCheck expiration dates and contents for
completeness at least once a year and replace
missing/expired items.
!To prevent damage, always disengage
handle1 from upper trunk lip3 and lower
trunk floor cover before closing the trunk.
422 Practical hints
Where will I find...?
TIREFIT (CLK 63 AMG only)
The TIREFIT kit is located under the trunk
floor.
Lift up trunk floor cover and engage the
handle in the upper edge of trunk
(
page 421).
1Straps for soft top emergency opera-
tion, a pair of gloves
2Electric air pump
3Towing eye bolt
4Vehicle jack
5TIREFIT kit
6Wheel wrench
7Collapsible wheel chock
Vehicle tool kit
The vehicle tool kit is located in the storage
compartment underneath the trunk floor.
The following is included:
Towing eye bolt
Wheel wrench
Alignment bolt
Vehicle jack
Collapsible wheel chock
A pair of gloves
Straps for soft top emergency opera-
tion (CLK cabriolet only)
The spare wheel bolts are fixed at the
Minispare wheel.Removing the vehicle tool kit
Lift up trunk floor cover and engage the
handle in upper edge of trunk
(
page 421).
Example CLK coupe
1Retaining screw
2Storage well casing
Loosen retaining screw1 in the mid-
dle of storage well casing2 by turning
it counterclockwise.
Remove storage well casing2.
i(CLK cabriolet) Hex wrench:
You will find the hex wrench for manually operat-
ing the roll bars (
page 430) or the soft top
(
page 432) at the lower edge of the storage
well casing.