tow bar MERCEDES-BENZ R-Class 2012 W251 User Guide

XStop after driving for approximately ten
minutes and check the tire pressure with
the tire inflation compressor.GWARNING
If tire inflation pressure has fallen below
130 kPa (1.3 bar/26 psi) do not continue to
drive the vehicle.
Park your vehicle safely away from the
roadway and contact the nearest authorized
Mercedes-Benz Center or Roadside
Assistance.
Have the damaged tire replaced.
XCorrect the tire pressure if it is at least
130 kPa (1.3 bar/20 psi) (for the required
values, see the Tire and Loading
Information placard on the driver's side
B-pillar or the tire pressure table inside the
fuel filler flap).XTo increase the tire pressure: switch on
the tire inflation compressor.
TIREFIT kit version 1
XTo reduce the tire pressure (version 1):
open pressure release screw F on
pressure gauge G.
TIREFIT kit version 2
EPressure release buttonFPressure gaugeXTo reduce the tire pressure (version 2):
press pressure release button E on the
filler hose.XStow the tire sealant bottle and the tire
inflation compressor.XDrive to the nearest workshop and have the
tire changed there.XHave the tire sealant bottle replaced as
soon as possible at a qualified specialist
workshop, e.g. at an authorized Mercedes-
Benz Center.HEnvironmental note
Have the used tire sealant bottle disposed of
professionally, e.g. at an authorized
Mercedes-Benz Center.
XHave the tire sealant bottle replaced every
four years at a qualified specialist
workshop, e.g. an authorized Mercedes-
Benz Center.
Changing a wheel and mounting the
spare wheel
Preparing the vehicle
GWARNING
The wheel and tire size of the emergency
spare wheel/spare wheel may differ to that of
the damaged wheel. When using an
emergency spare wheel/spare wheel the
Flat tire303Breakdown assistanceZ

Towing and tow-starting
Important safety notes
GWARNING
If you tow the vehicle, you must use a rigid
towing bar if:
R the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the power supply
or the vehicle's electrical system.
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will need more
force to steer and brake, you may have to
depress the brake pedal with maximum force.
Before towing away, make sure that the
steering can be moved and is not locked.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum
permissible gross vehicle weight of your
vehicle.
It is better to have the vehicle transported
than to have it towed.
! You may only tow the vehicle a maximum
distance of 30 miles (50 km). A towing
speed of 30 mph (50 km/h) must not be
exceeded.
For towing distances over 30 miles
(50 km), the vehicle must loaded onto a
transporter.
! Only secure the tow rope or tow bar at the
towing eyes. Otherwise, the vehicle could
be damaged.
! Do not use the towing eye for recovery,
as this could damage the vehicle. If in
doubt, recover the vehicle with a crane.
! When towing, pull away slowly and
smoothly. If the tractive power is too high,
the vehicles could be damaged.
! Do not tow with sling-type equipment.
This could damage the vehicle.
! When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop
button. Otherwise, the automatic
transmission may shift to position P when
the driver's or front-passenger door are
opened, which could lead to damage to the
transmission.
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission.
If the vehicle has suffered transmission
damage, have it transported on a transporter
or trailer.
The automatic transmission must be in
position N when the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 2 in
the ignition lock
R cannot shift the automatic transmission to
position N
i Before the vehicle is towed, switch off the
automatic locking feature ( Y page 208).
You could otherwise be locked out when
pushing or towing the vehicle.
Installing/removing the towing eye
Installing the towing eye
Vehicles with a trailer tow hitch: if possible
secure the towing device on the trailer tow
hitch ( Y page 191).
XRemove the towing eye from the vehicle
tool kit ( Y page 296).GWARNING
The exhaust tail pipe may be hot. You could
burn yourself if you touch the tail pipe. Be
particularly careful when removing the rear
cover.
The mountings for the removable towing eyes
are located in the bumpers. They are at the
front and at the rear, under the covers.
Towing and tow-starting315Breakdown assistanceZ

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)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire
width in percent.
Tire pressure
This is pressure inside the tire applying an
outward force to each square inch of the tire's
surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold. For this,
the vehicle must have been stationary for at
least three hours or not have traveled more
than 1.6 km (1 mile) in this time.
Tire pressure of cold tires
Tire pressure when the vehicle has been
stationary for at least three hours or not have
traveled more than 1.6 km (1 mile) in this
time.
Tread
The part of the tire that comes into contact
with the road.
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
bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
part and more than 2.3 kilograms (5 lbs).
These optional extras, such as high-
performance brakes, level control, a roof rack
or a high-performance battery, are not
included in the curb weight and accessory
weight.
TIN (Tire Identification Number)
This is a unique identifier 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 made up of the
manufacturer's identity code, tire size, tire
type code and the 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.
TWR (Tongue Weight Rating)
The TWR specifies the maximum permissible
weight that the ball coupling of the trailer tow
hitch can support.
Definition of terms for tires and loading345Wheels and tiresZ