79 Safety and Security
Occupant safety
Enhanced seat belt reminder system
When the engine is started, the seat belt
telltale< will always illuminate
for 6 seconds to remind you and your pas-
sengers to fasten your seat belts.
If the driver’s seat belt is not fastened
when the engine is started, an additional
warning chime will also sound for a maxi-
mum of 6 seconds or until the driver’ s
seat belt is fastened.
If after these 6 seconds the driver’s or the
front passenger’s seat belt (with the front
passenger seat occupied) is not fastened
with both doors closed,
the seat belt telltale< remains illu-
minated for as long as either the driv-
er’s or front passenger’s seat belt is not
fastened.
and if the vehicle speed once exceeds
15 mph (25 km/h), the seat belt
telltale< starts flashing and a
warning chime sounds with increasing
and side (CLK coupe: front side impact
air bags, rear side impact air bags*, and
window curtain air bags. CLK cabriolet:
head-thorax air bags and rear side im-
pact air bags* and ETD) impacts which
exceed preset deployment thresholds.
Never wear the shoulder belt under your
arm, against your neck or off your shoul-
der. In a frontal crash, your body would
move too far forward. That would
increase the chance of head and neck
injuries. The belt would also apply too
much force to the ribs or abdomen,
which could severely injure internal or-
gans such as your liver or spleen.
Never wear belts over rigid or breakable
objects in or on your clothing, such as
eyeglasses, pens, keys, etc., as these
might cause injuries.
Position the lap belt as low as possible
on your hips and not across the abdo-
m e n . I f t h e b e l t i s p o s i t i o n e d a c r o s s y o u r
abdomen, it could cause serious injuries
in a crash.
Never use a seat belt for more than one
person at a time. Do not fasten a seat
belt around a person and another
person or other objects.
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 always use
a lap-shoulder belt. The lap belt portion
should be positioned as low as possible
on the hips to avoid any possible
pressure 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
restraints, toddler restraints or children
in booster seats, always follow the child
seat manufacturer’s instructions.
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.
350 Operation
Tires and wheels
Tire width
The tire width1 (
page 349) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (
page 349) 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 349) 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 351).Rim diameter
The rim diameter4 (
page 349) 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 349) 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 354) where the maximum load
associated with the load index is indicated
in kilograms and lbs.
Warning!G
The tire load rating must always be at least
half of the GAWR (
page 358) of your
vehicle. Otherwise, tire failure may be the
result which may cause an accident and/or
serious personal injury to you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
Warning!G
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard located on
the driver’s door B-pillar. Overloading the
tires can overheat them, possibly causing a
blowout. Overloading the tires can also
result in handling or steering problems, or
brake failure.
356 Operation
Tires and wheels
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.
Treadwear
The treadwear grade is a comparative rat-
ing based on the wear rate of the tire when
tested under controlled conditions on a
specified government test course. For ex-
ample, a tire graded 150 would wear one
and one-half (1
1/2) times as well on the
government course as a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from the norm due to variations in driving
habits, service practices and differences in
road characteristics and climate.
Traction
The traction grades, from highest to low-
est, are AA, A, B, and C. Those grades rep-
resent the tire’s ability to stop on wet
pavement as measured under controlled
conditions on specified government test
surfaces of asphalt and concrete. A tire
marked C may have poor traction
performance.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
TreadwearTractionTemperature
200AAA
Warning!G
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
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.
370 Operation
Vehicle care
Soft top (CLK cabriolet)
Frequent cleaning reduces the
dirt-repellent effect of the soft top.
Intensive cleaning with Mercedes-Benz
car-care products for convertible soft tops
can help to restore the dirt-repellent
effect. Contact an authorized
Mercedes-Benz Center for detailed
information.
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.
Incorrect cleaning and care, as well as
ageing, can cause the soft-top seams to
leak. Have the soft-top seams sealed at a
Mercedes-Benz Center.!Make sure the windshield wiper switch is
set to0 (
page 56). Otherwise, e.g. the rain
sensor could activate and cause the wipers to
move unintentionally. This may lead to vehicle
damage.
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.
iAfter running the vehicle through an
automatic car wash, wipe any wax off of the
windshield (
page 373). This will prevent
smears and reduce wiping noise which can be
caused by residual wax on the windshield.
When leaving the car wash, make sure the mir-
rors are folded out. Otherwise they may vibrate.
iIf the soft top is kept in the storage
compartment for a lengthy period, raise it and air
out with the windows open about every
4months.
Place a suitable cover over the soft top if you are
leaving the vehicle parked in the open for an
extended period of time.
!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.
Never use hot-wax when you run the vehicle
through an automatic car wash, as you may
damage the soft top material.
488 Technical data
Main dimensions and weights
Main dimensions
Weights
ModelCLK 350CLK 550CLK 63 AMG
Overall vehicle length183.3 in (4 657 mm)183.3 in (4 657 mm)183.3 in (4 657 mm)
Overall vehicle width
(exterior rear view mirrors
folded out) 78.4 in (1 991 mm)78.4 in (1 991 mm)78.4 in (1 991 mm)
Overall vehicle height
Coupe:
Cabriolet:
55.4 in (1 408 mm)
55.6 in (1 413 mm)55.4 in (1 408 mm)
55.4 in (1 408 mm)
55.3 in (1 400 mm)
Overall vehicle height when
opening/closing soft top80.2 in (2 038 mm)81.0 in (2 057 mm)80.6 in (2 047 mm)
Wheelbase106.9 in (2 715 mm)106.9 in (2 715 mm)106.9 in (2 715 mm)
Track, front58.8 in (1 493 mm)58.9 in (1 497 mm)58.9 in (1 495 mm)
Track, rear58.0 in (1 474 mm)58.2 in (1 478 mm)58.0 in (1 474 mm)
Roof load max.
(CLK coupe only)
220 lbs (100 kg)
Trunk load max.220 lbs (100 kg)