2008 MERCEDES-BENZ SL55AMG service

291 Operation
Tires and wheels
Tires and wheels
See an authorized Mercedes-Benz Center
for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice concerning tire service and
purchase.Important guidelines

Only use sets of tires and rims of the
same type and make.

Tires must be of the correct size for the
rim.

Break in new tires for approximately
60 miles (100 km) at moderate
speeds.

Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire inflation pressure loss and
damage to the tire beads.

If vehicle is heavily loaded, check tire
inflation pressure and correct as
required.

Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths of less than
1/8in (3 mm).

When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension
components can be damaged.

The operating clearance of the wheels
and the tires may no longer be correct.
Warning!G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can
result in the bolts loosening and possibly an
accident.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on re-
treads. The operating safety of the vehicle
cannot be assured when such tires are used.

292 Operation
Tires and wheels
Tire care and maintenance
Regularly check your tire inflation pressure
at least once a month. For more informa-
tion on checking tire inflation pressure,
see “Recommended tire inflation pres-
sure” (
page 300).Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:

excessive treadwear (page 293)

cord or fabric showing through the
tire’s rubber

bumps, bulges, cuts, cracks or splits in
the tread or side of the tire
Replace the tire if you find any of the above
conditions.
Make sure you also inspect the spare tire
periodically for condition and inflation.
Spare tires will age and become worn over
time even if never used, and thus should be
inspected and replaced when necessary.Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:

Driving style

Tire inflation pressure

Distance driven
Warning!G
Regularly check the tires for damage. Dam-
aged tires can cause tire inflation pressure
loss. As a result, you could lose control of
your vehicle.
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
Warning!G
Tires and spare tire should be replaced after
6 years, regardless of the remaining tread.

315 Operation
Tires and wheels
For additional information on tire load
rating, see “Load identification”
(
page 317).
Tire speed rating
The tire speed rating6 (
page 313)
indicates the approved maximum speed
for the tire.Summer tires
Warning!G
The tire load rating must always be at least
half of the GAWR (
page 323) of your vehi-
cle. Otherwise, tire failure may be the result
which may cause an accident and/or seri-
ous 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.
iTire load rating5 (page 313) and tire
speed rating6 (
page 313) are also referred
to as “service description”.
Warning!G
Even when permitted by law, never operate
a vehicle at speeds greater than the
maximum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire
failure, causing loss of vehicle control and
possibly resulting in an accident and/or
personal injury and possible death, for you
and for others.
iTire load rating5 (page 313) and tire
speed rating6 (
page 313) are also referred
to as “service description”.
IndexSpeed rating
Qup to 100 mph (160 km/h)
Rup to 106 mph (170 km/h)
Sup to 112 mph (180 km/h)
Tup to 118 mph (190 km/h)
Hup to 130 mph (210 km/h)
Vup to 149 mph (240 km/h)
Wup to 168 mph (270 km/h)
Yup to 186 mph (300 km/h)
(Y)above 186 mph (300 km/h)
ZRabove 149 mph (240 km/h)

316 Operation
Tires and wheels

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 exam-
ple: 245/40 ZR18). To determine the
maximum speed capability of the tire,
the service description for the tire must
be referred to. The service description
is comprised of the tire load rating5
(
page 313) and the tire speed
rating6 (
page 313).
If your tire includes “ZR” in the size
designation and no service
description5 and6 (
page 313) is
given, the tire manufacturer must be
consulted for the maximum speed ca-
pability. If a service description5 and6
(
page 313) is given, the speed capa-
bility is limited by the speed symbol in
the service description.
Example: 245/40 ZR18 97Y.
In this example, “97Y” is the service
description. The letter “Y” designates
the speed rating and the speed capabil-
ity of the tire is limited to 186 mph
(300 km/h).

Any tire with a speed capability above
186 mph (300 km/h) must include a
“ZR” in the size designation AND the
service description must be placed in
parenthesis. Example: 275/40 ZR 18
(99Y). The “(Y)” speed rating in paren-
thesis designates the maximum speed
capability of the tire as being above
186 mph (300 km/h). Consult the tire
manufacturer for the actual maximum
permissible speed of the tire.All-season and winter tires
IndexSpeed rating
QM+S1
1or M+S.for winter tires
up to 100 mph (160 km/h)
TM+S1up to 118 mph (190 km/h)
HM+S1up to 130 mph (210 km/h)
VM+S1up to 149 mph (240 km/h)
iNot all M+S rated tires provide special win-
ter performance. Make sure the tires you use
show M+S and the mountain/snowflake sym-
bol.marking on the tire sidewall. These tires
meet specific snow traction performance re-
quirements of the Rubber Manufacturers Associ-
ation (RMA) and the Rubber Association of
Canada (RAC) and have been designed specifi-
cally for use in snow conditions.

321 Operation
Tires and wheels
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.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 Mo-
tor 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.
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.

327 Operation
Winter driving
Winter driving
Before the onset of winter, have your vehi-
cle winterized at an authorized
Mercedes-Benz Center. This service in-
cludes:

Check of anticorrosion and antifreeze
concentration.

Addition 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 sol-
vent/antifreeze which is formulated for
temperatures below freezing point
(
page 464).

Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
that the engine can be started and the
electro-hydraulic brake system will be
fully operational 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
symbol.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 winter
tires mounted are of the same make and
have the same tread design.
!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.

330 Operation
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 mes-
sage will notify you when the next mainte-
nance service is due.
Starting approximately 1 month before the
next maintenance service is due, one of
the following messages will appear in the
right multifunction display while you are
driving or when you switch on the ignition
(example service A):
Service A In XXXXX Miles (Km)
Service A In XXX Days
Service A Due Now
The type of maintenance service due is in-
dicated in the left multifunction display:
9Basic service (A)
½Extended service (B)
!Failure to have the vehicle maintained in
accordance with the Maintenance Booklet and
the maintenance service indicator at the desig-
nated times/mileage may result in vehicle dam-
age 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.

331 Operation
Maintenance
Clearing the maintenance service indi-
cator message
The maintenance service indicator mes-
sage is automatically cleared after approx-
imately 30 seconds

after you have switched on the ignition

after you have reached the mainte-
nance service threshold while driving
You can also clear the maintenance ser-
vice indicator message yourself.
1Reset button
Press reset button1 on the instru-
ment cluster.
The maintenance service indicator
message is cleared and the standard
display appears in the multifunction
display (
page 149).Maintenance service term exceeded
If you have exceeded the suggested main-
tenance service term, you will see the fol-
lowing message in the right multifunction
display:Service A Exceeded By XXXX Miles (Km)
Service A Exceeded By XXX Days
In addition, a signal sounds when the mes-
sage appears.
Any authorized Mercedes-Benz Center will
reset the maintenance service indicator
following a completed maintenance ser-
vice.