XTo open/close: turn thumbwheel :
clockwise or counter-clockwise.
Setting the rear-compartment air
vents
Setting the center vents in the rear
compartment
:Rear-compartment air vent thumbwheel;Rear-compartment air vent, right=Rear-compartment air vent, leftXTo open/close: turn thumbwheel : up or
down.122Setting the air ventsClimate control
Calibrating the compassXMake sure that there is sufficient space for
you to drive in a circle without impeding the
remaining traffic.
In order to calibrate the compass correctly,
observe the following points:
R calibrate the compass in the open and not
in the vicinity of steel constructions or high-
voltage transmission lines.
R switch off electrical consumers, for
example, the climate control, windshield
wipers or rear window defroster.
R close all doors and the trunk lid.
XSwitch the ignition on.XPress a round pin into opening =
( Y page 260) for approximately six seconds
until the C symbol appears in compass
display ; (Y page 260).XDrive a full circle at approximately 3 mph
(5 km/h) to 6 mph (10 km/h).
Once the calibration has been successfully
completed, the current direction appears in
compass display ; (Y page 260).
Floormat on the driver's side
GWARNING
Whenever you are using a floormat, make sure
there is enough clearance and that the
floormat is securely fastened.
The floormat should always be securely
fastened using the fastening equipment.
Before driving off, check that the floormat is
securely in place and adjust it if necessary. A
loose floormat could slip and hinder proper
functioning of the pedals.
Do not place several floormats on top of each
other as this may impair pedal movement.
XSlide the seat backwards.XTo install: place the floormat in the
footwell.XPress studs : onto retainers ;.XTo remove: pull the floormat off
retainers ;.XRemove the floormat.Features261Stowing and featuresZ
Further information on tire loads
( Y page 311).
Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards
The Uniform Tire Quality Grading is a U.S.
Government requirement. Their purpose is to
provide drivers with consistent and reliable
information regarding tire performance. Tire
manufacturers are required to grade tires
using three performance factors: tread
wear :, tire traction ;, and temperature
resistance =. Although not a Government of
Canada requirement, all tires made for sale in
North America have these grades branded on
the sidewall.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
For example:
Tread wearTractionTemperature200AAA
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Tread wear
The tread wear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
U.S. Government test course. For example, a
tire graded 150 would wear one and one-half
times as well on the government course as a
tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm, due to variations in driving habits,
service practices and differences in road
characteristics and climate conditions.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance.
GWARNING
If ice has formed on the road, tire traction will
be substantially reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road
surfaces.
You should pay special attention to road
conditions when temperatures are around
the freezing point.
Mercedes-Benz recommends a minimum tire
tread depth of 1
/ 6 in (4 mm) for all four winter
310Uniform Tire Quality Grading StandardsWheels and tires