305 Operation
Tires and wheels
Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa) or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least three hours or
driven no more than one mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.DOT (D
epartment o
f T
ransportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross A
xle W
eight R
ating)
The GAWR is the maximum permissible
axle weight. The gross vehicle weight on
each axle must never exceed the GAWR for
the front and rear axle indicated on the
certification label located on the driver’s
door B-pillar.
GVW (G
ross V
ehicle W
eight)
The GVW comprises the weight of the
vehicle including fuel, tools, spare wheel,
installed accessories, passengers and
cargo and, if applicable, trailer tongue
load. The GWV must never exceed the
GWVR indicated on the certification label
located on the driver’s door B-pillar.
306 OperationTires and wheelsGVWR (G
ross V
ehicle W
eight R
ating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight of
the vehicle including all options, passen-
gers, fuel, and cargo and, if applicable,
trailer tongue load). It is indicated on
certification label located on the driver’s
door B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kPa to one psi; another metric unit for
air pressure is bars. There are
100 kilopascals (kPa) to one bar.
Maximum load rating
The maximum load in kilograms and
pounds that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
vehicle capacity weight and production
options weight.Maximum tire inflation pressure
This number is the greatest amount of air
pressure that should ever be put in the tire
under normal driving conditions.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by
68 kilograms (150 lbs).
Occupant distribution
The distribution of occupants in a vehicle
at their designated seating positions.
Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty
battery, and special trim.PSI (P
ounds per s
quare i
nch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
Recommended tire inflation pressure
listed on placard located on driver’s door
B-pillar for normal driving conditions.
Provides best handling, tread life and
riding comfort.
Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated.
Sidewall
The portion of a tire between the tread and
the bead.
307 Operation
Tires and wheels
TIN (T
ire I
dentification N
umber)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters
concerning tires and gives purchases the
means to easily identify such tires. The TIN
is comprised of “Manufacturer’s identifica-
tion mark”, “Tire size”, “Tire type code”
and “Date of manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.
Tire ply composition and material used
This indicates the number of plies or the
number of layers of rubber-coated fabric in
the tire tread and sidewall. Tire manufac-
turers also must indicate the ply materials
in the tire and sidewall, which include
steel, nylon, polyester, and others.Tire speed rating
Part of tire designation; indicates the
speed range for which a tire is approved.
Traction
Force exerted by the vehicle on the road
via the tires. The amount of grip provided.
Tread
The portion of a tire that comes into
contact with the road.
Treadwear indicators
Narrow bands, sometimes called
“wear bars” that show across the tread of
a tire when only
1/6in (1.6 mm) of tread
remains.Uniform Tire Quality Grading Standards
A tire information system that provides
consumers with ratings for a tire’s traction,
temperature and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The
ratings are molded into the sidewall of the
tire.
Vehicle capacity weight
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle's
designated seating capacity.
Vehicle maximum load on the tire
Load on an individual tire that is
determined by distributing to each axle its
share of the maximum loaded vehicle
weight and dividing it by two.
392 Practical hintsFlat tire
After driving vehicle for an initial
10 minutes, check tire inflation pres-
sure using the pressure gauge on the
air pump.
Visit an authorized Mercedes-Benz
Center as soon as possible to obtain a
new TIREFIT kit.
Bring used TIREFIT materials to an au-
thorized Mercedes-Benz Center for
proper disposal.
Replace your TIREFIT container every
four years. Replacement containers are
available at your authorized
Mercedes-Benz Center.
Warning!
G
If tire inflation pressure has fallen below
20 psi (1.3 bar) do not continue to drive the
vehicle.
Park your vehicle safely away from the road-
way and contact the nearest authorized
Mercedes-Benz Center or Roadside
Assistance.
If tire inflation pressure is at least
20 psi (1.3 bar), inflate tire to correct pres-
sure (see placard on the driver’s door
B-pillar), and drive vehicle to nearest tire re-
pair facility to have tire repaired or replaced.
Recommended duration of use:
300 miles (500 km) at 50 mph (80 km/h)
with the recommended tire inflation pres-
sure.
Warning!
G
Follow recommend inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.
Warning!
G
Do not exceed vehicle speed of 50 mph
(80 km/h). A TIREFIT repair is not designed
to operate at higher speeds.
The sticker must be attached on the instru-
ment cluster where it will be easily seen by
the driver.
Vehicle handling characteristics may
change. Adapt your driving accordingly.
466 IndexTurn signals 23, 52
Additional in mirrors 381
Front bulbs 381
Indicator lamps 25
Rear bulbs 381
Turning off the engine 58
U
Uniform Tire Quality Grading
Standards 307
Units
Setting speedometer units 148
Setting temperature units 148
Setting tire inflation pressure
units 156
Unlocking 34
Centrally from inside 111
Driver’s door in an emergency 374
Fuel filler flap 267
Storage compartments 231, 375
Trunk 98, 108
Trunk (KEYLESS-GO*) 105
Trunk in an emergency 375
Vehicle in an emergency 374
With the SmartKey 34With the SmartKey with
KEYLESS-GO* 35, 99
Uphill driving
Cruise control 206
Upholstery
Cleaning 321
Upshifting 166
V
Vehicle
Individual settings 144
Locking 29
Locking in an emergency 376
Minimum distance (Parktronic*) 225
Towing 408
Unlocking 29
Unlocking in an emergency 374
Vehicle capacity weight 307
Vehicle care
Cup holder 320
Gear selector lever 320
Hard plastic trim items 320Headliner 320
Leather upholstery 321
Plastic and rubber parts 321
Seat belts 320
Steering wheel 320
Upholstery 321
Wood trims 321
Vehicle level 221, 444
Changing 222
Setting 222
Vehicle level control 444
Vehicle level control switch 30
Vehicle lighting
Checking 269
Vehicle loading terminology 305
Vehicle maximum load on the tire 307
Vehicle status messages 335
Vehicle tool kit 372
Ventilation and residual heat 190
VIN (vehicle identification number) 418,
444
Voice control system* 23, 444
Hands-free microphone 31