Page 255 of 417

254 OperationTires and wheels
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 under
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).
Tire care and maintenanceRegularly 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 262).
Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:
excessive treadwear (
page 255)
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.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.
Have worn or damaged tires replaced in
pairs (front pair or rear pair). Otherwise the
driving stability of the vehicle will be ad-
versely affected.
Warning!
G
Have worn or damaged tires replaced in
pairs (front pair or rear pair). Otherwise, the
driving stability of the vehicle will be ad-
versely affected. Warning!
G
Tires should be replaced after six years,
regardless of the remaining tread.
Page 271 of 417

270 OperationTires and wheelsRim diameter
The rim diameter4 (
page 269) 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 269) 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 1356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 274) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.For additional information on tire load
rating, see “Load identification”
(
page 272).
Warning
G
The tire load rating must always be at least
half of the GAWR (
page 279) 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 or vehicle capacity
weight as indicated on the 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 269) and
Tire speed rating6 (page 269) are
also referred to as “service descrip-
tion”.
Page 272 of 417

271 Operation
Tires and wheels
Tire speed rating
The tire speed rating6 (
page 269)
indicates the approved maximum speed
for the tire.Summer tires
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 269) and the tire speed
rating6 (
page 269).
If your tire includes “ZR” in the size
designation and no service
description5 and6 (
page 269) is
given, the tire manufacturer must be
consulted for the maximum speed ca-
pability.
If a service description5 and6
(
page 269) 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).
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 269) and
Tire speed rating6 (page 269) are
also referred to as “service descrip-
tion”.
Index
Speed rating
Q
up to 100 mph (160 km/h)
R
up to 106 mph (170 km/h)
S
up to 112 mph (180 km/h)
T
up to 118 mph (190 km/h)
H
up to 130 mph (210 km/h)
V
up to 149 mph (240 km/h)
W
up to 168 mph (270 km/h)
Y
up to 186 mph (300 km/h)
(Y)
above 186 mph (300 km/h)
ZR
above 149 mph (240 km/h)
Page 273 of 417
272 OperationTires and wheels
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
Load identification
1Load identification
Index
Speed rating
QM+S
up to 100 mph (160 km/h)
TM+S
up to 118 mph (190 km/h)
HM+S
up to 130 mph (210 km/h)
VM+S
up to 149 mph (240 km/h)
iThe marking “M+S” next to the service
description designates tires with mud
and snow capabilities.
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.
Page 277 of 417

276 OperationTires and wheelsUniform 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.
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
Page 284 of 417

283 Operation
Tires and wheels
Removing anti-theft wheel nuts
Unscrew anti-theft wheel nut1 using
wheel nut key2.
Replace anti-theft wheel nut1 with
one of the regular wheel bolts.
Fasten the wheel bolt and tighten it
with a torque wrench to a tightening
torque of 95 lb-ft (130 Nm).Fitting anti-theft wheel nuts
Unscrew a wheel bolt from one of the
wheels.
Replace that wheel bolt with one of the
anti-theft wheel nuts1 delivered with
your vehicle.
Fasten anti-theft wheel nut1 using
wheel nut key2 and tighten with a
torque wrench to a tightening torque of
95 lb-ft (130 Nm).
Warning!
G
The wheels could come loose if the wheel
bolts are not tightened to a torque of 95 lb-ft
(130 Nm). Have the tightening torque
checked after changing a wheel.
Warning!
G
The wheels could come loose if the wheel
bolts are not tightened to a torque of 95 lb-ft
(130 Nm). Have the tightening torque
checked after changing a wheel.
iKeep the anti-theft wheel nut key in a
convenient place in your vehicle where
you and service personnel can always
find it easily when it is needed.iIf you should lose the anti-theft wheel
nut key or one of the anti-theft wheel
nuts, please contact an authorized
Mercedes-Benz Center for a replace-
ment.
Page 285 of 417

284 OperationWinter drivingBefore the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Center. This service
includes:
Check of anticorrosion and antifreeze
concentration.
Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent/antifreeze which is formulated
for below freezing temperatures
(page 382).
Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to make
sure that the engine can be started,
even at low ambient temperatures.
Tire change. Mercedes-Benz recom-
mends M+S rated radial-ply tires with a
minimum tread depth of approximately 1/6in (4 mm) on all four wheels for the
winter season.
Winter tires*
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. 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 that all
mounted winter tires are of the same make
and have the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your
vehicle, you must place a notice to this
effect where it will be seen by the driver.
Such notices are available from your tire
dealer or from any authorized
Mercedes-Benz Center.
!A wheel change should only be carried
out at an authorized Mercedes-Benz
Center. Otherwise there is a danger of
damaging the vehicle by jacking it up
incorrectly.Warning!
G
Winter tires with a tread depth under
1/6in
(4 mm) must be replaced. They are no
longer suitable for winter operation.
Page 287 of 417

286 OperationMaintenanceIn order to maintain the performance and
safety of your SLR, we strongly recom-
mend that you have your vehicle serviced
by an authorized Mercedes-Benz Center,
every 12 months, even if the vehicle has
covered less than 10 000 miles
(15 000 km) in that time.
The maintenance service indicator will
notify you when your next maintenance
service is due within the next 12 months or
10 000 miles (15 000 km), whichever
comes sooner.
Failure to have the vehicle maintained in
accordance with the Maintenance Booklet
and maintenance service indicator at the
designated times/mileage will result in
vehicle damage not covered by the
Mercedes-Benz Limited Warranty.Before your next maintenance service is
due, one of the following messages will ap-
pear in the right multifunction display while
you are driving or when you switch on the
ignition:
Service in.. days
Service in.. km
When the maintenance service is due, the
display message Service Due now!
ap-
pears.Clearing the maintenance service
indicator
1Reset button
The service display is automatically
cleared after 30 seconds. You can also
clear it yourself.
Press reset button 1.