Example:
R
Treadwea rgrade: 200
R Tractio ngrade: AA
R Temperature grade: A
All passenge rcar tires must conform to the
statutory safety requirements in additio nto
these grades.
i Thea ctual values for tires ar evehicle-
specifi cand ma ydeviate from the values in
the illustration.
Treadwear The treadwea
rgrade is acomparative rating
based on the wearr ate of thetirew hen tested
unde rcontrolled conditions on aspecified
U.S. government course. For example, atire
graded 150 would wear one and one-half
times as well on the government course as a
tire graded 100.
The relative performanc eoftires 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 G
WARNING
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.
! Avoid wheelspin. This can lead to damage
to the drive train.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
the tire's ability to stop on awet surface as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. Atire marked Cmay have poor
traction performance. The safe speed on
awet, sno wcovered or icy
road is always lower than on dry road
surfaces.
You should pay special attention to road
conditions when temperatures are around
freezin gpoint.
Mercedes-Ben zrecommends aminimum
tread dept hof001Fin(4 mm )ona ll four winter
tires. Observe the legally required minimum
tire tread depth (Y page335). Winter tires can
reduce the braking distance on snow-covered
surfaces in comparison with summer tires.
The braking distance is still much further than
on surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further informatio nonwinter tires (M+S
tires) (Y page336).
Temperature G
WARNING
The temperature grade for this tire is
established for atire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heat build-up and possible tire
failure.
The temperature grades are A(the highest),
B, and C. Thes erepresent the tire's
resistanc etothe generatio nofheat and its
ability to dissipate heat when tested under
controlled conditions on aspecified indoor
laboratory test wheel. Sustained high
temperature can cause the material of the tire
to degenerat eand reduce tire life, and
excessive temperature can lead to sudden
tire failure. The grade Ccorresponds to alevel
of performanc ewhich all passenger car tires
must meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades Band A
represent higher levels of performanc eonthe
laboratory test wheel than the minimum
required by law. 350
All about wheelsa
nd tiresWheels and tires
Cur
bw eight
The weight of avehicle with standard
equipment includin gthe maximum capacity
of fuel, oil and coolant .Italso includes the air-
conditionin gsystem and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
Maximu mload rating
The maximum tir eload is the maximum
permissible weight in kilograms or lbs for
which atireisa pproved.
Maximu mpermissible tir epressure
Maximum permissible tir epressure for one
tire.
Maximu mload on one tire
Maximum load on one tire. This is calculated
by dividin gthe maximum axle load of one axle
by two.
PSI (pounds per squar einch)
As tandar dunitofm easure for tire pressure.
Aspect ratio
Relationship between tire height and tire
width in percent.
Tirep ressure
This is pressure inside the tire applying an
outward forc etoeach 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 tirep ressure
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has been driven for less than
1m ile (1.6 km). Tread
The part of the tire that comes intoc
ontact
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 preven tthe tire from
comin gloose 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 kilograms (5 lbs).
These optional extras, such as high-
performance brakes, level control, aroof rack
or ah igh-performanc ebattery, are not
included in the curb weight and the weight of
the accessories.
TIN (Tire Identification Number)
This is aunique identifier which can be used
by atire manufacturer to identify tires, for
example for aproduct 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 atire.
Traction
Traction is the result of friction between the
tires and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are
distributed over the tire tread. If the tire tread
is level with the bars, the wear limit of 0014in
(1.6 mm) has been reached. 356
All about wheels and tiresWheels and tires
