70 Safety and SecurityOccupant safety
Emergency tensioning device (ETD),
seat belt force limiter
The seat belts are equipped with emergen-
cy tensioning devices and belt force
limiters.
The ETD is designed to activate in the
following cases:
in frontal or rear-end impacts
exceeding a preset severity level
if the restraint systems are operational
and functioning correctly, see
1indicator lamp (
page 60)In an impact, emergency tensioning
devices remove slack from the belts. Belt
force limiters reduce the force exerted by
the seat belts on occupants during a crash.
Automatic comfort-fit feature seat belt
An automatic comfort-fit feature for front
seats reduces the retracting force of the
seat belts when they are in normal use.
Belts should not be worn twisted. In a
crash, you wouldn’t have the full width
of the belt to distribute impact forces.
The twisted belt against your body could
cause injuries.
Pregnant women should also use a
lap-shoulder belt. The lap belt portion
should be positioned as low as possible
on the hips to avoid any possible pres-
sure on the abdomen.
Never place your feet on the instrument
panel, dashboard, or on the seat. Always
keep both feet on the floor in front of the
seat.
When using a seat belt to secure infant
or toddler restraints or children in
booster seats, always follow the child
seat manufacturer’s instructions.
!The ETDs for the front seats will only
activate if the front seat belts are fas-
tened (latch plate properly inserted
into buckle).
The ETDs for the rear seats will activate
with or without the respective seat
belts fastened.
Warning!
G
An emergency tensioning device (ETD) that
was activated must be replaced.
When disposing of the emergency tension-
ing device, our safety instructions must be
followed. These are available at your
authorized Mercedes-Benz Center.
326 OperationTires and wheelsTire labeling
Besides tire name (sales designation) and
manufacturer name, a number of markings
can be found on a tire.
Following are some explanations for the
markings on your vehicle’s tires:1Uniform Quality Grading Standards
(
page 333)
2DOT, Tire Identification Number (TIN)
(page 330)
3Maximum tire load (
page 332)
4Maximum tire inflation pressure
(
page 332)
5Manufacturer
6Tire ply material (
page 335)
7Tire size designation, load and speed
rating (
page 326)
8Load identification (
page 330)
9Tire nameTire size designation, load and speed
rating
1Tire width
2Aspect ratio in %
3Radial tire code
4Rim diameter
5Tire load rating
6Tire speed rating
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.
For more information, see “Rims and
tires” (
page 445).
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.
327 Operation
Tires and wheels
General:
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 326) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (page 326) 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 326) 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 328).
Rim diameter
The rim diameter4 (
page 326) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
333 Operation
Tires and wheels
Always follow the recommended tire
inflation pressure (
page 322) for proper
tire inflation. Uniform Tire Quality Grading Standards
(U.S. vehicles)
Tire manufacturers are required to grade
tires based on three performance
factors: treadwear, traction and
temperature resistance.
1Treadwear
2Traction
3Temperature resistanceQuality grades can be found, where appli-
cable, on the tire sidewall between tread
shoulder and maximum section width. For
example:
All passenger car tires must conform to
federal safety requirements in addition to
these grades.
Warning!
G
Never exceed the max. tire inflation
pressure. Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and / or unevenly, adverse-
ly affect handling and fuel economy, and are
more likely to fail from being overheated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride com-
fort, wear unevenly, increase stopping dis-
tance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road de-
bris, potholes etc.
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.
Treadwear
Traction
Temperature
200
AA
A
335 Operation
Tires and wheels
Tire ply material
1Plies in sidewall
2Plies under tread
This marking tells you about the type of
cord and number of plies in the sidewall
and under the tread.
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.
Warning!
G
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underin-
flation, or excessive loading, either sepa-
rately or in combination, can cause
excessive heat build-up and possible tire
failure.
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.
347 Operation
Vehicle care
Engine cleaning
Prior to cleaning the engine compartment,
make sure to protect electrical compo-
nents and connectors from the intrusion of
water and cleaning agents.
Corrosion protection, such as MB Anticor-
rosion Wax, should be applied to the
engine compartment after every engine
cleaning. Before applying, all control
linkage bushings and joints should be
lubricated. The poly-V-belt and all pulleys
should be protected from any wax.
Vehicle washing
Do not use hot water or wash your vehicle
in direct sunlight. Only use a mild car wash
detergent, such as Mercedes-Benz
approved Car Shampoo.
Thoroughly spray the vehicle with a dif-
fused jet of water. Direct only a very weak
spray towards the ventilation intake. Use
plenty of water and rinse the sponge and
chamois frequently. Rinse with clear water and thoroughly dry
with a chamois. Do not allow cleaning
agents to dry on the finish.
Due to the width of the vehicle, fold in
exterior rear view mirrors prior to running
the vehicle through an automatic car wash
to prevent damage to the mirrors.
In the winter, thoroughly remove all traces
of road salt as soon as possible.
When washing the underbody, do not
forget to clean the inner sides of the
wheels.Soft top
Clean soft top with soft top raised and
locked. Lower the soft top into the storage
compartment only if the soft top is com-
pletely dry. If the soft top is kept in the
storage compartment for a lengthy period,
raise it and air out with the windows open
about every 4 months.
Light colored soft tops should be cleaned
frequently to prevent spots and dirt from
setting in, which could stain and discolor
the soft top material permanently.
iVehicles with KEYLESS-GO*:
If a door handle is hit by a strong jet of
water, and a SmartKey with
KEYLESS-GO* is in close proximity, i.e.
within approximately 3 ft
(approximately 1 m), the vehicle could
be inadvertently locked or unlocked.
!Remove bird droppings immediately.
The organic acid damages the material
and causes the soft top to leak
Never use a power washer to clean the
soft top, as you may damage the soft
top material.
Do not use sharp-edged instruments
for the removal of ice and snow.
451 Technical data
Main dimensions
Main dimensions
Model
CLK 320
CLK 500
CLK 55 AMG
Overall vehicle length
182.8 in (4 643 mm)
182.8 in (4 643 mm)
182.8 in (4 643 mm)
Overall vehicle width
68.5 in (1 740 mm)
68.5 in (1 740 mm)
68.5 in (1 740 mm)
Overall vehicle height
55.4 in (1 406 mm)
55.4 in (1 408 mm)
55.4 in (1 408 mm)
Overall vehicle height when
opening/closing soft top
80.9 in (2 055 mm)
81.0 in (2 057 mm)
80.6 in (2 047 mm)
Wheelbase
106.9 in (2 715 mm)
106.9 in (2 715 mm)
106.9 in (2 715 mm)
Track, front
58.8 in (1 493 mm)
58.9 in (1 497 mm)
58.9 in (1 497 mm)
Track, rear
58.0 in (1 474 mm)
58.2 in (1 478 mm)
58.2 in (1 478 mm)