For example, a load rating of 91 corresponds
to a maximum load of 1356 lb (615 kg) the
tire is designed to support. See also
“Maximum tire load”  (Y  page 246) where the
maximum load associated with the load index
is indicated in kilograms and lbs.
For additional information on the load index,
see “Load identification” ( Y page 253).
Speed symbol GWarning!
Even when permitted by law, never operate a
vehicle at speeds greater than the maximum
speed rating of the tires.
Exceeding the maximum speed for which tires
are rated can lead to sudden tire failure,
causing loss of vehicle control and possibly
resulting in an accident and/or serious
personal injury and possible death, for you
and for others.
Regardless of the tire speed rating, local
speed limits should be obeyed. Use prudent
driving speeds appropriate to prevailing
conditions.
Speed symbol  B indicates the approved
maximum speed (tire speed rating) for the
tire.
Summer tires
IndexSpeed ratingQup to 100 mph (160 km/h)Rup to 106 mph (170 km/h)Sup to 112 mph (180 km/h)Tup to 118 mph (190 km/h)Hup to 130 mph (210 km/h)Vup to 149 mph (240 km/h)Wup to 168 mph (270 km/h)Yup to 186 mph (300 km/h)ZR...Yup to 186 mph (300 km/h)IndexSpeed ratingZR...(..Y)above 186 mph (300 km/h)ZRabove 149 mph (240 km/h)
R At the tire manufacturer’s option, any tire
with a speed capability above 149 mph
(240 km/h) can include a “ZR” in the size
designation (for example: 245/40 ZR18).
To determine the maximum speed
capability of the tire, the service
description for the tire must be referred to.
The service description is comprised of
load index  A and speed symbol  B.
If your tire includes “ZR” in the size
designation and no service description is
given, the tire manufacturer must be
consulted for the maximum speed
capability.
If a service description is given, the speed
capability is limited by the speed symbol in
the service description. Example:
245/40 ZR18 97Y. In this example, “97Y”
is the service description. The letter “Y”
designates the speed rating and the speed
capability of the tire is limited to 186 mph
(300 km/h).
R Any tire with a speed capability above
186 mph (300 km/h) must include a “ZR”
in the size designation AND the service
description must be placed in parenthesis.
Example: 275/40 ZR 18 (99Y). The “(Y)”
speed symbol in parenthesis designates
the maximum speed capability of the tire
as being above 186 mph (300 km/h).
Consult the tire manufacturer for the actual
maximum permissible speed of the tire.
All-season and winter tires
IndexSpeed ratingQ M+S 17up to 100 mph (160 km/h)T M+S17up to 118 mph (190 km/h)17
or M+S ifor winter tires252Tires and wheelsOperation
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Version 2
XAfter driving the vehicle for an initial
10 minutes, check the tire inflation
pressure using pressure gauge G on the
air pump.
GWarning!
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
roadway and contact the nearest authorized
Mercedes-Benz Center or Roadside
Assistance.
Have the damaged tire replaced.
If the tire inflation pressure is at least 20 psi
(1.3 bar), inflate or deflate the tire to the
correct tire inflation pressure (see Tire and
Loading Information placard on the driver’s
door B-pillar):
XTo increase tire inflation pressure:
Switch on the electric air pump.
XTo decrease tire inflation pressure:
Version 1: Open vent screw F on
pressure gauge G (Y page 338).
Version 2: Press deflate button F located
at the end of the filler hose.
XDrive to the nearest qualified workshop,
e.g. an authorized Mercedes-Benz Center,
to have the damaged tire replaced.
XRecommended duration of use: A
maximum of 300 miles (500 km) at 50 mph
(80 km/h) or below with the recommended
tire inflation pressure.
XContact an authorized Mercedes-Benz
Center as soon as possible to obtain a new
TIREFIT kit.
XBring used TIREFIT materials to an
authorized Mercedes-Benz Center for
proper disposal.
XReplace your TIREFIT container every
4 years. Replacement containers are
available at any authorized Mercedes-Benz
Center.
Mounting the spare wheel
Introduction
XPrepare the vehicle as described
(Y page 336).
XTake the following out of the vehicle:
Rspare wheel
Rjack
Rwheel wrench
Rcollapsible wheel chock
Ralignment bolt
For information on where to find the
respective items, see “Where will I find ...?”
(Y page 284) and (Y page 286).
iVehicles without spare wheel are not
factory-equipped with the tools required for
a wheel change such as a jack or a wheel
wrench. Some tools required for a wheel
change are specific to your vehicle.
Contact an authorized Mercedes-Benz
Center to obtain the tools approved for
your vehicle. This section describes the
wheel change using the tools approved and
recommended for your vehicle.
340Flat tirePractical hints
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