78 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
passenger 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
passenger’s seat belt (with the passenger
seat occupied) are not fastened with both
doors closed,
the seat belt telltale< remains illu-
minated for as long as either the driv-
er’s or 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 intensity for a maximum of 60 seconds
or until both the driver’s and
passenger’s seat belt are fastened.
If the driver’s or the passenger’s seat
belt remains unfastened after
60 seconds, the warning chime stops
sounding. The seat belt telltale<
stops flashing but continues to be
illuminated.
The seat belt telltale< will only go out
if both the driver’s and the passenger’s
seat belt (with the passenger seat occu-
pied) are fastened, or the vehicle is stand-
ing still and a door is opened.
For more information, see the “Practical
hints” section (
page 353).
Seat belts should not be worn twisted.
In a crash, you would not have the full
width of the seat belt to manage impact
forces. The twisted seat 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
or toddler restraints or children in
booster seats, always follow the child
seat manufacturer’s instructions.
322 Operation
Tires and wheels
Tire 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. Tire width
The tire width1 (
page 322) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (
page 322) 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 322) 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 323).
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
329 Operation
Tires and wheels
Quality 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 perfor-
mance.
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.
331 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 three 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 GWV must never exceed the
GWVR indicated on the certification label
located on the driver’s door B-pillar.
342 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 Anticorrosion Wax should be applied to
the engine compartment after every en-
gine 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
In the winter, thoroughly remove all traces
of road salt as soon as possible.
When washing the vehicle underbody, do
not forget to clean the inner sides of the
wheels.Hand-wash
Do not use hot water or wash your vehicle
in direct sunlight.
Use only a mild car wash detergent,
such as Mercedes-Benz approved Car
Shampoo.
Thoroughly spray the vehicle with a
diffused 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 clean water and thoroughly
dry with a chamois.
Do not allow cleaning agents to dry on
the finish.Automatic car wash
You can have your car washed in an auto-
matic car wash from the start. Automatic
car washes without brushes are prefera-
ble.
To protect the filter system, switch the
climate control (
page 178) or auto-
matic climate control (
page 190) to
air recirculation mode.
If the vehicle is very dirty, prewash it be-
fore running it through the automatic car
wash.
!Do not use scouring agents on these parts.
Never apply strong force and only use a soft,
non-scratching cloth when cleaning the vehicle.
Do not attempt to wipe the surface with a dry
cloth or sponge.
Otherwise you may scratch or damage the paint.
!Do not clean your vehicle in an automatic
touchless car wash which uses caustic spray.
Otherwise the caustic spray will damage the
paint or ornamental moldings.
!Make sure that the windshield wiper switch
is set to0 (
page 56). Otherwise, 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.
449 Technical data
Main Dimensions
Main Dimensions
ModelSLK 280SLK 350SLK 55 AMG
Overall vehicle length161.0 in (4 089 mm)161.0 in (4 089 mm)161.1 in (4 093 mm)
Overall vehicle width
(exterior mirrors folded out)77.5 in (1 969 mm)77.5 in (1 969 mm)77.5 in (1 969 mm)
Overall vehicle height51.0 in (1 296 mm)51.1 in (1 298 mm)50.6 in (1 286 mm)
Overall vehicle height when
opening/closing hardtop60.8 in (1 544 mm)60.8 in (1 544 mm)60.4 in (1 534 mm)
Wheelbase95.7 in (2 430 mm)95.7 in (2 430 mm)95.7 in (2 430 mm)
Track, front60.2 in (1 530 mm)60.1 in (1 526 mm)60.0 in (1 524 mm)
Track, rear61.0 in (1 549 mm)61.0 in (1 549 mm)61.0 in (1 549 mm)
Turning circle34.5 ft (10.51 m)34.5 ft (10.51 m)34.5 ft (10.51 m)