MERCEDES-BENZ SLK55AMG 2008 R171 Owner's Manual

330 Operation
Tires and wheels
Temperature
The temperature grades are A (the high-
est), B, and C, representing the tire’s resis-
tance to the generation of heat and its
ability to dissipate heat when tested under
controlled conditions on a specified indoor
laboratory test wheel. Sustained high tem-
perature can cause the material of the tire
to degenerate and reduce tire life, and ex-
cessive temperature can lead to sudden
tire failure. The grade C corresponds to a
level of performance which all passenger
car tires must meet under the Federal
Motor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of
performance on the laboratory test wheel
than the minimum required by law.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.
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 are specific to each vehicle and may vary
from data shown in above illustration.

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.

332 Operation
Tires and wheels
GVWR (Gross Vehicle Weight Rating)
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
certification label located on the driver’s
door B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 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.Maximum tire inflation pressure
This number is the greatest amount of air
pressure that should ever be put in the tire
under normal driving conditions.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by
68 kilograms (150 lbs).
Occupant distribution
The distribution of occupants in a vehicle
at their designated seating positions.
Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty
battery, and special trim.PSI (Pounds per square inch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
The recommended tire inflation pressure
for normal driving conditions is listed on
the Tire and Loading Information placard
located on the driver’s door B-pillar and
provides best handling, tread life and
riding comfort. If so equipped, supplemen-
tal information pertaining to special driving
situations can be found on the tire inflation
pressure label on the inside of the fuel filler
flap.
Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated.
Sidewall
The portion of a tire between the tread and
the bead.

333 Operation
Tires and wheels
TIN (Tire Identification Number)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters
concerning tires and gives purchases the
means to easily identify such tires. The TIN
is comprised of “Manufacturer’s identifica-
tion mark”, “Tire size”, “Tire type code”,
and “Date of manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.
Tire ply composition and material used
This indicates the number of plies or the
number of layers of rubber-coated fabric in
the tire tread and sidewall. Tire manufac-
turers also must indicate the ply materials
in the tire and sidewall, which include
steel, nylon, polyester, and others.Tire speed rating
Part of tire designation; indicates the
speed range for which a tire is approved.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle’s
designated seating capacity.
Traction
Force exerted by the vehicle on the road
via the tires. The amount of grip provided.
Tread
The portion of a tire that comes into
contact with the road.
Treadwear indicators
Narrow bands, sometimes called
“wear bars” that show across the tread of
a tire when only
1/16in (1.6 mm) of tread
remains.Uniform Tire Quality Grading Standards
A tire information system that provides
consumers with ratings for a tire’s traction,
temperature and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The
ratings are molded into the sidewall of the
tire.
Vehicle maximum load on the tire
Load on an individual tire that is
determined by distributing to each axle its
share of the maximum loaded vehicle
weight and dividing it by two.

334 Operation
Tires and wheels
Rotating tires
Tire rotation can be performed on vehicles
with tires of the same dimension all
around. If your vehicle is equipped with
tires of the same dimension all around,
tires can be rotated, observing a
front-to-rear rotation pattern that will
maintain the intended rotation (spinning)
direction of the tire (
page 307).
In some cases, such as when your vehicle
is equipped with mixed-size tires (different
tire dimension front vs. rear), tire rotation
is not possible.If applicable to your vehicle’s tire configu-
ration, tires can be rotated according to
the tire manufacturer’s recommended in-
tervals in the tire manufacturer’s warranty
pamphlet located in your vehicle literature
portfolio. If none is available, tires should
be rotated every 3 000 to 6 000 miles
(5 000 to 10 000 km), or sooner if neces-
sary, according to the degree of tire wear.
The same rotation (spinning) direction
must be maintained (
page 307).
Rotate tires before the characteristic tire
wear pattern becomes visible (shoulder
wear on front tires and tread center wear
on rear tires).
Thoroughly clean the mounting face of
wheels and brake discs, i.e. the inner side
of the wheels/tires, during each rotation.
Check for and ensure proper tire inflation
pressure.For information on wheel change, see the
“Practical hints” section (
page 392) and
(
page 408).
Warning!G
Rotate front and rear wheels only if the tires
are of the same dimension.
If your vehicle is equipped with mixed-size
tires (different tire dimensions front vs.
rear), tire rotation is not possible.
Warning!G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
80 lb-ft (110 Nm).
Only use genuine Mercedes-Benz wheel
bolts specified for your vehicle’s rims.

335 Operation
Winter driving
Winter driving
Before the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Center. This service
includes:

Checking anticorrosion and antifreeze
concentration.

Adding of cleaning concentrate to the
water of the windshield and headlamp
cleaning* system. Add MB Windshield
Washer Concentrate “MB SummerFit”
to a pre-mixed windshield washer
solvent/antifreeze which is formulated
for temperatures below freezing point
(
page 458).

Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to make
sure the engine can be started, even at
low ambient temperatures.

Tire change.
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Not all M+S rated
tires provide special winter performance.
Make sure the tires you use show M+S and
the mountain/snowflake.marking on
the tire sidewall. These tires meet specific
snow traction performance requirements
of the Rubber Manufacturers Association
(RMA) and the Rubber Association of
Canada (RAC) and have been designed
specifically for use in snow conditions. Use
of winter tires is the only way to achieve
the maximum effectiveness of the ABS and
ESP
® in winter operation.
For safe handling, make sure all mounted
winter tires are of the same make and have
the same tread design.Always observe the speed rating of the
winter tires mounted to your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such no-
tices are available at your tire dealer or any
authorized Mercedes-Benz Center.
!When scraping ice or snow from the rear
window, be careful not to damage the sealing
strip or apertures along the side of the window.
Warning!G
Winter tires with a tread depth of less than 1/6 in (4 mm) must be replaced. They are
no longer suitable for winter operation.

336 Operation
Winter driving
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:

Use of snow chains is not permissible
with all wheel/tire combinations
(
page 442).

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 447).
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 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 442).
!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 88) before
setting the vehicle in motion. This will improve
the vehicle’s traction.

337 Operation
Maintenance
Maintenance
We strongly recommend that you have
your vehicle serviced by an authorized
Mercedes-Benz Center, in accordance with
the Maintenance Booklet at the times
called for by the maintenance service indi-
cator.Maintenance service indicator
message
The maintenance service indicator
message will notify you when the next
maintenance service is due.
Starting approximately 1 month before the
next maintenance service is due, one of
the following messages will appear in the
multifunction display while you are driving
or when you switch on the ignition (exam-
ple service A):
Service A Due In XXXXX Miles (Km)
Service A Due In XXX Days
Service A Due In X Day
Service A Due Now
The maintenance services will be indicated
by showing a service type A through
type H in the multifunction display.
Types A through H are classified based on
estimated time needed to perform the
maintenance service, ranging:
from
Service A
(approximately 1 hour)
to
Service H
(approximately 8 hours)
Refer to Maintenance Booklet for a listing
of maintenance services and intervals the
need to be performed at.
!Failure to have the vehicle maintained in
accordance with the Maintenance Booklet and
the maintenance service indicator at the
designated times/mileage will result in vehicle
damage not covered by the Mercedes-Benz
Limited Warranty.
iThe Maintenance System in your vehicle
tracks distance driven and the time elapsed
since the last maintenance service and calcu-
lates other maintenance service work required.

338 Operation
Maintenance
Clearing the maintenance service
indicator message
The maintenance service indicator
message is automatically cleared:

after approximately 10 seconds when
you switch on the ignition or when
reaching the service threshold while
driving

after approximately 30 seconds once
the suggested maintenance service
term has passed
You can also clear it yourself.
Press reset buttonJ(page 26) on
the instrument cluster.
The maintenance service indicator
message is cleared and the standard
display appears in the multifunction
display (
page 127).
Maintenance service term exceeded
If you have exceeded the suggested main-
tenance service term, you will see the fol-
lowing message in the multifunction
display:
Service A Exceeded By XXXXX Miles (Km)
Service A Exceeded By XXX Days
Service A Exceeded By X Day
In addition, a signal sounds when the
message appears.
Any authorized Mercedes-Benz Center will
reset the maintenance service indicator
following a completed maintenance
service.Calling up the maintenance service
indicator display
You can call up the maintenance service in-
dicator display at any time to check when
the next maintenance service is due.
Switch on the ignition (page 37).
The standard display menu appears in
the multifunction display (
page 127).
Press buttonjork on the mul-
tifunction steering wheel repeatedly
until the maintenance service indicator
display with the service symbol 9
appears in the multifunction display.
iThe menu overview can be found on
(
page 124).

339 Operation
Maintenance
Resetting the maintenance service
indicator
In the event that the maintenance service
on your vehicle is not carried out by an
authorized Mercedes-Benz Center, you can
have the maintenance service indicator
reset. The automotive maintenance facility
carrying out the maintenance service will
find the information for resetting the main-
tenance service indicator in the mainte-
nance-relevant literature for your vehicle.
Such literature is available from any autho-
rized Mercedes-Benz Center or directly
from Mercedes-Benz.iIf the battery is disconnected, the days of
disconnection will not be included in the count
shown by the maintenance service indicator. To
arrive at the true maintenance service deadline,
you will need to subtract these days from the
days shown in the maintenance service indicator
message or maintenance service indicator dis-
play.
Do not confuse the maintenance service indica-
tor with the engine oil level indicatorN.
iIf the maintenance service indicator was
inadvertently reset, have an authorized
Mercedes-Benz Center correct it.
Only reset if the proper maintenance service has
been performed. Resetting the system without
performing the proper maintenance service as
called for by the maintenance service indicator
will result in engine damage and/or other vehicle
damage not covered by the Mercedes-Benz
Limited Warranty.