X
Remove the objects that are preventing the
trailer from rolling, e.g. wheel chocks.
X Release the trailer parking brake.
i The subharness of the vehicle has a cable
connection to the brake lamp indicator
lamp.
Observe the maximum permissible trailer
dimensions (width and length).
Most federal states and all Canadian provin-
ces require by law:
R safety chains between the towing vehicle
and the trailer. The chains should be cross-
wound under the trailer drawbar. They must be fastened to the vehicle's trailer cou-
pling, not to the bumper or the axle.
Leave enough slack in the chains. This
allows you to drive round tight corners.
R a separate brake system for certain types
of trailer.
R a safety switch for braked trailers. Find out
the specific requirements according to the
applicable laws.
If the trailer detaches from the towing vehi- cle, the safety switch applies the trailer's
brakes. Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed
restrictions. Make sure your vehicle/trailer
combination complies with local laws. This
not only means where you live, but also any-
where you are driving to. Information is avail-
able from the police and local authorities.
Observe the following when towing a trailer:
R Practice driving around bends, stopping
and backing up at a place where there is no
traffic. This enables you to gain experience and get used to the new handling charac-
teristics.
R Before driving, check:
- that the trailer tow hitch and ball cou-
pling are secure
- that the safety switch for a braked trailer
is functioning properly
- that the safety chains are secure and not
damaged
- that the electrical connections are
secure
- that the lights are working
- that the wheels are in good order and the
tire pressure is correct
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer has electronically controlled
brakes, pull the vehicle/trailer combina-
tion away carefully. Brake manually using
the brake controller and check that the
brakes are working.
R Secure the load on the trailer according to
the applicable specifications and current
standards on securing loads (Y page 242).
R When driving with a trailer, check at regular
intervals that the load is secured and that
the brakes and lights are working.
R Bear in mind that the handling will be less
stable when towing a trailer than when driv-
ing without one. Avoid sudden steering
movements.
R The vehicle/trailer combination is heavier,
accelerates more slowly and has a
decreased gradient climbing capability and
a longer braking distance.
It is more susceptible to crosswinds and
requires cautious steering.
R If possible, do not brake suddenly, but
rather moderately at first so that the trailer
can activate its brakes. Then increase the
force on the brake pedal.
R If the automatic transmission repeatedly
shifts between gears when driving on 176
Towing a trailerDriving and pa
rking
When parking your vehicle, make sure that
the tires do not get deformed by the curb or
other obstacles. If it is necessary to drive over
curbs, speed humps or similar elevations, try to do so slowly and not at a sharp angle. Oth- erwise, the tires, particularly the sidewalls,
can get damaged. Regular wheel and tire checks
G
WARNING
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.
Check the wheels and tires of your vehicle for damage regularly, i.e. at least every two
weeks, as well as after driving off-road or on
rough roads. Damaged wheels can cause a
loss of tire pressure. Pay particular attention
to damage such as:
R cuts in the tires
R punctures
R tears in the tires
R bulges on tires
R deformation or severe corrosion on wheels
Regularly check the tire tread depth and the
condition of the tread across the whole width of the tire (Y page 285). If necessary, turn the
front wheels to full lock in order to inspect the
inner side of the tire surface.
All wheels must have a valve cap to protect
the valve against dirt and moisture. Do not
install anything onto the valve other than the
standard valve cap or other valve caps
approved for your vehicle by dealers listed on
the inside of the front cover. Do not install any
other valve caps or systems, e.g. tire pressure
monitor systems.
Regularly check the pressure of all the tires,
particularly prior to long trips. Adjust the tire pressure if necessary (Y page 288).The service life of tires depends on various
factors, including the following:
R driving style
R tire pressure
R mileage Tire tread
G
WARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water.
This means that on wet road surfaces, the risk of hydroplaning increases, in particular where speed is not adapted to suit the driving con-
ditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at differ-
ent locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
R Summer tires: 00CEin (3 mm)
R M+S tires: 00CFin (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached. Marker
0043shows the location where the bar
indicator (arrow) for tread wear is integrated
into the tire tread.
Tread wear indicators (TWIs) are required by
law. Six indicators are positioned over the tire
tread. They are visible once the tread depth is Operation
285Wheels and tires Z
0087
Maximum tire pressure (Y page 290)
0085 Manufacturer
0083 Tire material (Y page 302)
0084 Tire size designation, load-bearing capa-
city and speed index (Y page 300)
006B Tire name
The markings described above are on the tire in addition to the tire name (sales designa-
tion) and the manufacturer's name.
i Tire data is vehicle-specific and may devi-
ate from the data in the example.
Tire size designation, load bearing index and speed index G
WARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle. 0043
Design standard
0044 Tire width
0087 Nominal aspect ratio in %
0085 Tire code
0083 Rim diameter
0084 Load bearing index
006B Speed index
General: depending on the manufacturer's
standards, the size imprinted in the tire wall may not contain any letters or may contain
one letter
0043that precedes the size descrip-
tion
If "LT" precedes the size description (as
shown above): these are light truck tires
according to U.S. manufacturing standards.
If "C" precedes the size description: these are
commercial motor vehicle tires according to
European manufacturing standards.
Tire width: tire width0044shows the nominal
tire width in millimeters.
Aspect ratio: aspect ratio0087is the size ratio
between the tire height and tire width and is
shown in percent. The aspect ratio is calcu-
lated by dividing the tire width by the tire
height.
Tire code: tire code0085specifies the tire type.
"R" represents radial tires. "D" represents
diagonal tires, "B" represents diagonal radial
tires.
Rim diameter: rim diameter0083is the diam-
eter of the bead seat, not the diameter of the rim flange. The rim diameter is specified in
inches (in).
Load-bearing index: load-bearing index0084
is a numerical code that specifies the maxi-
mum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum permissi-
ble load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on the driver's side (Y page 295).
Example:
The load-bearing index 120 indicates a max-
imum load of 3,042 lb (1,380 kg) for the tire.
If two load-bearing capacity indices are speci- fied (as shown above), the first number states
the load-bearing capacity for single tires, the second number the load-bearing capacity for
twin tires. For further information on the max- imum tire load in kilograms and pounds, see
(Y page 301).
For further information on the load-bearing
index, see "Load index" (Y page 301).300
What you should know about wheels and tiresWheels and tires
is bar. 100 kilopascals (kPa) are the equiva-
lent of 1 bar.
Load index
In addition to the load bearing index, a load
index can be stamped onto the sidewall of the
tire. It specifies the load-bearing capacity of
the tire more precisely.
Curb weight
The weight of a vehicle with standard equip-
ment including the maximum filling capacity
of fuel, oil, and coolant. It also includes the
air-conditioning system and optional equip-
ment if these are installed on the vehicle, but
does not include passengers or luggage.
Maximum tire load
The maximum tire load in kilograms or
pounds is the maximum weight for which a
tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire.
Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing the maximum axle load of one axle by two.
PSI (Pounds per square inch)
Standard unit of measurement for tire pres-
sure.
Aspect ratio
Relationship between tire height and width in
percent.
tire pressure
Pressure inside the tire applying an outward
force to every square inch of the tire's sur-
face. Tire pressure is specified in pounds per square inch (psi), in kilopascal (kPa) or in bar.
Tire pressure should only be corrected when
the tires are cold. Cold tire pressure
The tires are cold:
R if the vehicle has been parked for at least
three hours without direct sunlight on the
tires, and
R if the vehicle has not been driven further
than 1 mile (1.6 km)
Tire tread
The part of the tire th at comes into contact
with the road.
Tire bead
The tire bead ensures that the tire sits
securely on the wheel. There are several steel wires in the bead to prevent the tire from
coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the
tire bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5lbs). These
optional extras, such as high-performance
brakes, a roof rack or a high-performance
battery, are not included in the curb weight
and the weight of the accessories.
TIN (Tire Identification Number)
A unique identification number which can be
used by a tire manufacturer to identify tires,
for example for a product recall, and thus
identify the purchasers. The TIN is composed of the manufacturer identification code, tire
size, tire model code and manufacturing date.
Load bearing index
The load bearing index (also load index) is a
code that contains the maximum load bearing capacity of a tire.
Traction
Traction is the result of friction between the
tires and the road surface. 304
What you should know about wheels and tiresWheels and tires