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 Pressure inside the tire applying an outward
force to every 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.
Cold tire pressure The tires are cold: R
if the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and R
if the vehicle has not been driven further than
1 mile (1.6 km)
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
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
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 pur-
chasers. The TIN is made up of the manufactur-
er'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 capa-
city of a tire.
Traction Traction is the result of friction between the tires
and the road surface.
Treadwear indicators Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of
Notes on the vehicle equipment – always equip
the vehicle with: R
with tires of the same size on a given axle (left
and right) R
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 ( Y
page 287).
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.
Emergency spare wheel
Important safety notes
G WARNING
The wheel or tire size as well as the tire type of
the spare wheel or emergency spare wheel
and the wheel to be replaced may differ.
Mounting an emergency spare wheel may
severely impair the driving characteristics.
There is a risk of an accident.
To avoid hazardous situations: R
adapt your driving style accordingly and
drive carefully. R
never mount more than one spare wheel or
emergency spare wheel that differs in size. R
only use a spare wheel or emergency spare
wheel of a different size briefly. R
do not switch ESP ®
off.R
have a spare wheel or emergency spare
wheel of a different size replaced at the
nearest qualified specialist workshop.
Observe that the wheel and tire dimensions
as well as the tire type must be correct.
When using an emergency spare wheel or spare
wheel of a different size, you must not exceed
the maximum speed of 50 mph (80 km/h).
Snow chains must not be mounted on emer-
gency spare wheels. General notes You can ask for information regarding permitted
emergency spare wheels at an authorized
Mercedes-Benz Center.
You should regularly check the pressure of the
emergency spare wheel, particularly prior to
long trips, and correct the pressure as neces-
sary ( Y
page 304). The value on the wheel is
valid.
An emergency spare wheel may also be moun-
ted against the direction of rotation. Observe
the time restriction on use as well as the speed
limitation specified on the emergency spare
wheel.
Replace the tires after six years at the latest,
regardless of wear. This also applies to the
emergency spare wheel.
i When you are driving with the collapsible
spare wheel mounted, the tire pressure loss
warning system or the tire pressure monitor
cannot function reliably. Only restart the tire
pressure loss warning system or tire pressure
monitor when the defective wheel has been
replaced with a new wheel.
Vehicles with tire pressure monitor: after
mounting an emergency spare wheel, the sys-
tem may still display the tire pressure of the
removed wheel for a few minutes. The value
displayed for the mounted emergency spare
wheel is not the same as the current tire pres-
sure of the emergency spare wheel.
"Minispare" emergency spare wheel/
collapsible spare wheel
Opening the stowage well
The emergency spare wheel can be found in the
stowage well under the trunk floor.326
Emergency spare wheel
Wheels and tires
