323 Operation
Tires and wheels
General:
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 324).
Rim diameter
The rim diameter4 (
page 322) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
332 OperationTires and wheelsTire 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 3 hours or driv-
en 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 (D
epartment o
f T
ransportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross A
xle W
eight R
ating)
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 V
ehicle W
eight)
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.
337 Operation
Winter driving
Block heater* (Canada only)
The engine is equipped with a block heat-
er.
The electrical cable may be installed at an
authorized Mercedes-Benz Center.
Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not to ex-
ceed 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.
Snow chains should only be used on
the rear wheels. Follow the manufac-
turer’s mounting instructions.
Only use snow chains that are ap-
proved by Mercedes-Benz. Your
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.
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.
!When driving with snow chains, always
select the raised level of the level con-
trol system Airmatic (
page 239).
Other settings may result in damage to
your vehicle.
iWhen driving with snow chains, you
may wish to deactivate the ESP
®
(
page 88) before setting the vehicle
in motion. This will improve the vehi-
cle’s traction.
361 Practical hints
What to do if …
Warning!
G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
vehicle placard or the tire inflation pressure
label. (If your vehicle has tires of a different
size than the size indicated on the vehicle
placard or the tire inflation pressure label,
you should determine the proper tire infla-
tion pressure for those tires).
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly under-inflated tire causes the tire to over-
heat and can lead to tire failure.
Under-inflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’s responsibility to maintain correct tire
pressure, even if under-inflation has not
reached the level to trigger illumination of
the TPMS low tire pressure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately
one minute and then remain continuously
illuminated. This sequence will continue
upon subsequent vehicle start-ups as long
as the malfunction exists. When the mal-
function indicator is illuminated, the system
may not be able to detect or signal low tire
pressure as intended.
TPMS malfunctions may occur for a variety
of reasons, including the installation of in-
compatible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction telltale after replacing
one or more tires or wheels on your vehicle
to ensure that the replacement or alternate
tires and wheels allow the TPMS to continue
to function properly.
372 Practical hintsWhat to do if …Display messages
Possible cause/consequence
Possible solution
Tire pres. monitor
inoperative
No wheel sensors
There are wheels without wheel sen-
sors mounted (e.g. winter tires).
Have the Advanced TPMS* checked by an au-
thorized Mercedes-Benz Center.
Have the wheel sensors installed by an
authorized Mercedes-Benz Center.
Tire pres. monitor
Wheel sensor missing
One or more sensors malfunc-
tion (e.g. battery is empty).
One or more wheels without
wheel sensors mounted (e.g.
spare tire).
The tire inflation pressure for the re-
spective tire is not shown in the mul-
tifunction display.
Have the Advanced TPMS* checked by an au-
thorized Mercedes-Benz Center.
Have the wheel sensors installed by an
authorized Mercedes-Benz Center.
398 Practical hintsWhere will I find ...?First aid kit
The first aid kit is in the storage compart-
ment at the front edge of the front passen-
ger seat.
1Tab
Pull tab1 upward.
Fold the covering forward.
Remove the first aid kit.
TIREFIT*
The TIREFIT kit is located under the trunk
floor.
Lift the trunk floor and engage the han-
dle in the upper edge of trunk.
1Vehicle tool kit
2Electric air pump
3TIREFIT kit
Spare wheel
The spare wheel is located under the trunk
floor.
Lift the trunk floor and engage the han-
dle in the upper edge of trunk.
Remove the luggage box (
page 401).
1Vehicle tool kit
2Spare wheel
3Luggage bowl
iCheck expiration dates and contents
for completeness at least once a year
and replace missing/expired items.
399 Practical hints
Where will I find ...?
Removing the spare wheel
Turn luggage bowl counterclockwise.
Remove spare wheel2.
Storing the spare wheel
Place spare wheel2 in wheel well.
Turn luggage bowl clockwise to its stop
to secure the spare wheel.
Vehicle tool kit
The vehicle tool kit is stored in the com-
partment underneath the trunk floor
(page 398).
The vehicle tool kit includes:
One pair of universal pliers
One towing eye bolt
One wheel wrench
One alignment bolt
One fuse extractor
One collapsible wheel chock
Spare fusesVehicle jack
!Always lower trunk floor before closing
the trunk.iVehicles with collapsible tire:
The electrical air pump is located under
the luggage bowl3.
Warning!
G
The jack is designed exclusively for jacking
up the vehicle at the jack take-up brackets
built into both sides of the vehicle. To help
avoid personal injury, use the jack only to lift
the vehicle during a wheel change. Never
get beneath the vehicle while it is supported
by the jack. Keep hands and feet away from
the area under the lifted vehicle. Always
firmly set parking brake and block wheels
before raising vehicle with jack.
Do not disengage parking brake while the
vehicle is raised. Be certain that the jack is
always vertical (plumb line) when in use, es-
pecially on hills. Always try to use the jack
on a level surface. Make sure the jack arm is
fully seated in the jack take-up bracket.
Always lower the vehicle onto sufficient
capacity jackstands before working under
the vehicle.
423 Practical hints
Flat tire
Visit an authorized Mercedes-Benz
Center as soon as possible to obtain a
new TIREFIT kit.
Bring used TIREFIT materials to an
authorized Mercedes-Benz Center for
proper disposal.
Replace your TIREFIT container every
4 years. Replacement containers are
available at your authorized
Mercedes-Benz Center.
Mounting the spare wheel
Warning!
G
Follow recommend inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.
Warning!
G
Do not exceed vehicle speed of 50 mph
(80 km/h). A TIREFIT repair is not designed
to operate at higher speeds.
The sticker must be attached on the instru-
ment cluster where it will be easily seen by
the driver.
Vehicle handling characteristics may
change. Adapt your driving accordingly.
Warning!
G
The dimensions of the spare wheel
(Minispare or collapsible tire) are different
from those of the road wheels. As a result,
the vehicle handling characteristics change
when driving with a spare wheel mounted.
Adapt your driving style accordingly.
The spare wheel is for temporary use only.
When driving with spare wheel mounted,
ensure proper tire pressure and do not ex-
ceed a vehicle speed of 50 mph (80 km/h).
Drive to the nearest Mercedes-Benz Center
as soon as possible to have the spare wheel
replaced with a regular road wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® when a Minis-
pare or collapsible tire is mounted.