298 OperationTires and wheelsTire 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 306).Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:
excessive treadwear (
page 299)
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
six years, regardless of the remaining tread.
299 Operation
Tires and wheels
Tread depth
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).
Treadwear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and
become visible at a tread depth of approx-
imately
1/16
in (1.6 mm), at which point
the tire is considered worn and should be
replaced.
Recommended minimum tire tread depth:
Summer tires
1/8in (3 mm)
Winter tires
1/6in (4 mm)
1TWI (T
read W
ear I
ndicator)
The treadwear indicator appears as a solid
band across the tread.Storing tires
Cleaning tires
Warning!
G
Although the applicable federal motor safety
laws consider a tire to be worn when the
treadwear indicators (TWI) become visible at
approximately
1/16in (1.6 mm), we recom-
mend that you do not allow your tires
to wear down to that level. As tread depth
approaches
1/8in (3 mm), the adhesion
properties on a wet road are sharply re-
duced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
!Keep unmounted tires in a cool, dry
place with as little exposure to light as
possible. Protect tires from contact
with oil, grease and gasoline.!Never use a round nozzle to power
wash tires. The intense jet of water can
result in damage to the tire.
Always replace a damaged tire.
301 Operation
Tires and wheels
1Driver’s door B-pillar
Following is a discussion on how to work
with the information contained on the two
placards with regards to loading your vehi-
cle.Tire and Loading Information
Your vehicle is equipped with either the
Tire and Loading Information placard
(Example A) or the Vehicle Tire Information
placard (Example B). Placard (Example A)
1Load limit information on the Tire and
Loading Information placard
The placard showing the load limit informa-
tion is located on the driver’s door B-pillar.
If your vehicle is equipped with the Tire and
Loading Information placard (Example A),
locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kilograms or XXX lbs.”
on this placard. The combined weight of all
occupants, cargo / luggage and trailer
tongue load (if applicable) should never
exceed the weight referenced in that
statement.
Warning!
G
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight as indicated on the placard 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.iData shown on placard examples is for
illustration purposes only. Load limit
data is specific to each vehicle and may
vary from data shown in the illustra-
tions below. Refer to placard on vehicle
for actual data specific to your vehicle.
306 OperationTires and wheelsRecommended tire inflation pressure
Your vehicle is equipped with either the
Tire and Loading Information placard
(Example A) or the Vehicle Tire Information
placard (Example B) located on the driver’s
door B-pillar (
page 301).The tire inflation pressure should be
checked regularly and should only be ad-
justed on cold tires. The tires can be con-
sidered cold if the vehicle has been parked
for at least three hours or driven less than
one mile (1.6 km).
Follow recommended cold tire inflation
pressures listed on placard.
Keeping the tires properly inflated
provides the best handling, tread life and
riding comfort.
In addition to the tire placard on the
driver’s door B-pillar, also consult the fuel
filler flap for any additional information
pertaining to special driving situations. For
more information, see “Important notes on
tire inflation pressure” (
page 307).Placard (Example A)
1Tire and Loading Information placard
with recommended cold tire inflation
pressures
Placard (Example A) lists the recommend-
ed cold tire inflation pressures for maxi-
mum loaded vehicle weight. The tire
inflation pressures listed apply to the tires
installed as original equipment.
Warning!
G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and / or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
iData shown on placard examples is for
illustration purposes only. Tire data is
specific to each vehicle and may vary
from data shown in the illustrations
below. Refer to placard on vehicle for
actual data specific to your vehicle.
307 Operation
Tires and wheels
Placard (Example B)
1Vehicle Tire Information placard with
recommended cold tire inflation
pressures
Placard (Example B) lists the recommend-
ed cold tire inflation pressures for maxi-
mum loaded vehicle weight. The tire
inflation pressures listed apply to the tires
installed as original equipment.Important notes on tire inflation
pressure
Tire temperature and tire inflation pressure
are also increased while driving, depending
on the driving speed and the tire load.
If you will be driving your vehicle at high
speeds of 100 mph (160 km / h) or higher,
where it is legal and conditions allow,
consult the placard on the inside of the fuel
filler flap on how to adjust the cold tire in-
flation pressure. If you do not adjust the
tire inflation pressure, excessive heat can
build up and result in sudden tire failure.Be sure to readjust the tire inflation
pressure for normal driving speeds. You
should wait until the tires are cold before
adjusting the tire inflation pressure.
Some vehicles may have supplemental tire
pressure information for vehicle loads less
than the maximum loaded vehicle condi-
tion. If such information is provided, it can
be found on the placard located on the in-
side of the fuel filler flap.
Tire inflation pressure changes by approxi-
mately 1.5 psi (0.1 bar) per 18°F (10°C) of
air temperature change. Keep this in mind
when checking tire inflation pressure
where the temperature is different from
the outside temperature.
iPlacard (Example B) may list
recommended cold tire inflation
pressures for different vehicle loads.
Warning!
G
If the tire inflation pressure repeatedly
drops:
Check the tires for punctures from
foreign objects.
Check to see whether air is leaking from
the valves or from around the rim.
308 OperationTires and wheelsChecking tire inflation pressure
Regularly check your tire inflation pressure
at least once a month.
Check and adjust the tire inflation
pressure when the tires are cold. The tires
can be considered cold if the vehicle has
been parked for at least three hours or
driven less than one mile (1.6 km).
If you check the tire inflation pressure
when the tires are warm (the vehicle has
been driven for several miles or sitting less
than three hours), the reading will be
approximately 4 psi (0.3 bar) higher than
the cold reading. This is normal. Do not let
air out to match the specified cold tire in-
flation pressure. Otherwise, the tire will be
underinflated.Checking tire inflation pressure
manually
Follow the steps below to achieve correct
tire inflation pressure:
Remove the cap from the valve on one
tire.
Firmly press a tire gauge onto the
valve.
Read tire inflation pressure on tire
gauge and check against the recom-
mended tire inflation pressure on the
placard on the driver’s door B-pillar
(page 306). If necessary, add air to
achieve the recommended tire inflation
pressure.
Install the valve cap.
Repeat this procedure for each tire.
Run Flat Indicator*
While the vehicle is being driven, the Run
Flat Indicator monitors the set tire inflation
pressures by evaluating each wheel’s rota-
tional speed. This allows the system to de-
tect a significant loss of pressure in a tire.
If a wheel’s rotational speed changes due
to falling tire inflation pressure, you will
see a corresponding warning message in
the multifunction display.
The Run Flat Indicator may function in a re-
stricted manner or with a delay if:
snow chains are mounted to the
vehicle
winter road conditions prevail
you are driving on a loose surface (e.g.
sand or gravel)
you are driving in a very sporty manner
(involving rapid acceleration or high
speeds in curves)
iIf you have overfilled the tire, release
tire inflation pressure by pushing the
metal stem of the valve with e.g. a tip of
a pen. Then recheck the tire inflation
pressure with the tire gauge.
309 Operation
Tires and wheels
Warning!
G
When the multifunction display shows the
message
Low pressure mode Check
tires max. Speed 50 mph
, one or more
of your tires is significantly under-inflated.
You should stop and check your tires as
soon as possible, and inflate them to the
proper tire inflation pressure as indicated on
the vehicle’s tire information placard. Driv-
ing on a significantly under-inflated tire
causes the tire to overheat and can lead to
tire failure. Under-inflation also reduces fuel
efficiency and tire tread life, and may affect
the vehicle’s handling and stopping ability.
Each tire, including the spare, should be
checked monthly when cold and set to the
recommended tire inflation pressure as
specified in the vehicle placard and owner’s
manual.
iThe recommended tire inflation pres-
sures for your vehicle can be found on
the tire placard located on the driver’s
door B-pillar (
page 301). The tire in-
flation pressures are not listed in the
owner’s manual.
Warning!
G
The Run Flat Indicator does not indicate a
warning for wrongly selected tire inflation
pressures. Always adjust tire inflation pres-
sure according to the placard on the driver’s
door B-pillar or fuel filler flap.
The Run Flat Indicator does not replace reg-
ular checks of the tire inflation pressures
since a gradual pressure loss in all four tires
cannot be detected by the Run Flat
Indicator.
The Run Flat Indicator is not able to issue a
warning due to a sudden dramatic loss of
tire inflation pressure (e.g. tire blowout
caused by a foreign object). In this case
bring the vehicle to a halt by carefully apply-
ing the brakes and avoiding abrupt steering
maneuvers.
310 OperationTires and wheels
Reactivating the Run Flat Indicator
The tire inflation pressure monitor must be
reactivated in the following situations:
If you have changed the tire inflation
pressure
If you have replaced the wheels or tires
If you have installed new wheels or
tires
Using the tire placard on the driver’s
door B-pillar or, if available, the inside
of the fuel filler flap, make sure the tire
inflation pressure of all four tires is cor-
rect.
Switch on the ignition (
page 35).
The standard display menu appears in
the multifunction display (page 122)
Press buttonk orj repeatedly
until the following message appears in
the multifunction display:Run Flat Indicator
active
Reactivation poss.: +
Press buttonæ.
The following message will appear in
the multifunction display:Tire pres. now
OK?
Warning!
G
Follow recommend tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and / or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight as indicated on the placard on the
driver’s door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout.
Warning!
G
The Run Flat Indicator can only warn you in
a reliable manner if you have set the correct
tire inflation pressures for each tire.
If an incorrect tire inflation pressure was
set, the system will monitor the pressure ac-
cording to the incorrect value.