MOExtended tires (tires with run-flat
properties)
With MOExtended tires (tires with run flat char-
acteristics), you can continue to drive your vehi-
cle even if there is a total loss of pressure in one
or more tires.
MOExtended tires may only be used in conjunc-
tion with an active tire pressure loss warning
system or with an active tire pressure monitor
and on wheels specifically tested by Mercedes-
Benz.
Notes on driving with MOExtended tires with a
flat tire (
Ypage 334).
Vehicles equipped with MOExtended tires are
not equipped with a TIREFIT kit at the factory. It
is therefore recommended that you additionally
equip your vehicle with a TIREFIT kit if you mount
tires that do not feature run-flat properties, e.g.
winter tires. A TIREFIT kit can be obtained from a qualified specialist workshop.
Winter operation
General notes
Have your vehicle winter-proofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Changing a wheel"
section (
Ypage 369).
Driving with summer tires
At temperatures below 45 ‡ (+7 †), summer
tires lose elasticity and therefore traction and
braking power. Change the tires on your vehicle
to M+S tires. Using summer tires at very cold
temperatures could cause cracks to form,
thereby damaging the tires permanently.
Mercedes-Benz cannot accept responsibility for
this type of damage.
GWARNING
Damaged tires can cause tire inflation pres-
sure loss. As a result, you could lose control of
your vehicle. There is a risk of accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
M+S tires
GWARNING
M+S tires with a tire tread depth of less than
ã in (4 mm) are not suitable for use in winter
and do not provide sufficient traction. There is
a risk of an accident.
M+S tires with a tread depth of less than ãin
(4 mm) must be replaced immediately.
At temperatures below 45 ‡(+7 †), use winter
tires or all-season tires. Both types of tire are
identified by the M+S marking.
Only winter tires bearing the isnowflake
symbol in addition to the M+S marking provide
the best possible grip in wintry road conditions.
Only these tires will allow driving safety systems
such as ABS and ESP
®to function optimally in
winter. These tires have been developed specif-
ically for driving in snow.
Use M+S tires of the same make and tread on all
wheels to maintain safe handling characteris-
tics.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
When you have mounted the M+S tires:
XCheck the tire pressures (Ypage 355).
XVehicles for Canada: restart the tire pres-
sure loss warning system (Ypage 356).
XRestart the tire pressure monitor
(Ypage 358).
Snow chains
GWARNING
If snow chains are installed to the front
wheels, they may drag against the vehicle
body or chassis components. This could
cause damage to the vehicle or the tires.
There is a risk of an accident.
To avoid hazardous situations:
Rnever install snow chains to the front
wheels
Ralways install snow chains in pairs to the
rear wheels.
Winter operation351
Wheels and tires
Z
iThe actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified U.S.
government course. For example, a tire graded
150 would wear one and one-half 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 cli-
mate.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor-
nering, hydroplaning, or peak traction char-
acteristics.
!Avoid wheelspin. This can lead to damage to
the drive train.
The traction grades – from highest to lowest –
are AA, A, B and C. Those grades represent the
tire's ability to stop on wet pavement as meas-
ured under controlled conditions on specified
government test surfaces of asphalt and con-
crete. A tire marked C may have poor traction
performance.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road surfaces.
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Mercedes-Benz recommends a minimum tread
depth of ãin (4 mm) on all four winter tires.
Observe the legally required minimum tire tread
depth (
Ypage 350). Winter tires can reduce the
braking distance on snow-covered surfaces in
comparison with summer tires. The braking dis-
tance is still much further than on surfaces that
are not icy or covered with snow. Take appro-
priate care when driving. Further information on winter tires (M+S tires)
(
Ypage 351).
Temperature
GWARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, or excessive loading, either separately or
in combination, can cause excessive heat
build-up and possible tire failure.
The temperature grades are A (the highest), B,
and C, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions
on a specified indoor laboratory test wheel. Sus-
tained high temperature can cause the material
of the tire to degenerate and reduce tire life, and
excessive 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.
All about wheels and tires363
Wheels and tires
Z
"ZR" inthe size descript ion, depending on the
manufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter?isthe diameter
of the bead seat, not the diameter of the rim
flange. The rim diameter isspecifie din
inches (in).
Load-bearing index: load-bearing indexAisa
numerical co dethat specifie s the maximum
load-bearing capacity of a tire.
Do not overload the tires byexcee ding the
specifie d loadlimit. The maximum permis sible
load can befound on the veh icle's Tire and
Loading Information placard on the B- pillaron
the driver's side (
Ypage 359).
Example:
Load-bearing index 91 indicates a maximum
load of 1,356 lb(615 kg) that the tires can bear.
For further information on the maximum tire
load inkilograms and lbs,see (
Ypage 366).
For further information on the load bearing
index, see "Load index" (
Ypage 366).
Speed rating: speed rating Bspecifie s the
maximum permis siblespeed of the tire.
iTire data isveh icle-specific and may deviate
from the data inthe example.
Regardless of the speed rating, always observe
the speed limits. Drive carefully and adapt your
driv ing style to the traff icconditions.
Summer tires
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)
ZR...Yup to 186 mph (300 km/h)
ZR...(..Y)over 186 mph (300km/ h)
ZRover 149 mph (240 km/h)
ROptionally, tires with a maximum permissible
speed of over 149 mph (240 km/h) may have
"ZR" in the size description, depending on the
manufacturer, e.g. 245/40 ZR18.
The service specification is made up of load-
bearing index Aand speed rating B.
RIf the size description of your tire includes
"ZR" and there are no service specifications,
ask the tire manufacturer in order to find out
the maximum permissible speed.
If a service specification is available, the max-
imum permissible speed is limited according
to the speed rating in the service specifica-
tion. Example: 245/40 ZR18 97 Y. In this
example, "97 Y" is the service specification.
The letter "Y" represents the speed rating. The
maximum permissible speed of the tire is limi-
ted to 186 mph (300 km/h).
RThe size description for all tires with maxi-
mum permissible speeds of over 186 mph
(300 km/h) must include "ZR", andthe ser-
vice specification must be given in parenthe-
ses. Example: 275/40 ZR 18 (99 Y). Speed
rating "(Y)" indicates that the maximum per-
missible speed of the tire is over 186 mph
(300 km/h). To find out the maximum per-
missible speed, ask the tire manufacturer.
All-weather tires and winter tires
IndexSpeed rating
Q M+S1up to 100 mph (160 km/h)
T M+S1up to 118 mph (190 km/h)
H M+S1up to 130 mph (210 km/h)
V M+S1up to 149 mph (240 km/h)
iNot all tires with the M+S marking provide
the driving characteristics of winter tires. In
addition to the M+S marking, winter tires also
have the isnowflake symbol on the tire
wall. Tires with this marking fulfill the require-
ments of the Rubber Manufacturers Associa-
tion (RMA) and the Rubber Association of
Canada (RAC) regarding the tire traction on
snow. They have been especially developed
for driving on snow.
An electronic speed limiter prevents your vehi-
cle from exceeding a speed of 130 mph
(210 km/h).
1Or M+S ifor winter tires.
All about wheels and tires365
Wheels and tires
Z
Observe the notes on recommended tire pres-
sures under various operating conditions
(
Ypage 352).
Check tire pressures regularly, and only when
the tires are cold. Comply with the maintenance
recommendations of the tire manufacturer in
the vehicle document wallet.
Notes on the vehicle equipment – always equip
the vehicle:
Rwith tires of the same size on a given axle (left
and right)
Rwith the same type of tires at a given time
(summer tires, winter tires, MOExtended
tires)
Exception: it is permissible to install a differ-
ent type or make in the event of a flat tire.
Observe the "MOExtended tires (tires with
run-flat characteristics" section (
Ypage 334).
Vehicles equipped with MOExtended tires are
not equipped with a TIREFIT kit at the factory. It
is therefore recommended that you additionally
equip your vehicle with a TIREFIT kit if you mount tires that do not feature run-flat properties, e.g.
winter tires. A TIREFIT kit may be obtained from
a qualified specialist workshop.
374Wheel/tire combination
Wheels and tires