Mercedes-Benz 2011 G-Class Operator's Manual page 266

Tire labeling
264
Example:
The load bearing index 91 is equivalent to a
maximum load of 1356 lbs (615 kg) that the
tire can carry. For further information on the
maximum tire load in kilograms and pounds,
see ( Y page 260).
For further information on the load bearing
index, see Load index (
Speed index: speed index B specifies the
approved maximum speed of the tire.
G
Warning
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 speed index, always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic
conditions.
Summer tires
Index Speed rating
Q Up to 100 mph (160 km/h)
R Up to 106 mph (170 km/h)
S Up to 112 mph (180 km/h)
T Up to 118 mph (190 km/h)
H Up to 130 mph (210 km/h)
V Up to 149 mph (240 km/h)
W Up to 168 mph (270 km/h)
Y Up to 186 mph (300 km/h)
ZR...Y Up to 186 mph (300 km/h)
21 or M+Si for winter tires.
Y page 265).
Summer tires
Index Speed rating
ZR...(..Y) above 186 mph (300 km/h)
ZR above 149 mph (240 km/h)
Optionally, tires with a maximum speed
R
rating of more than 149 mph (240 km/h)
may have "ZR" in the size description
depending on the manufacturer (e.g.
245/40 ZR 18).
The service specification is made up of load
bearing index A and speed index B.
If the size description of your tire includes
R
"ZR" and there are no service
specifications, ask the tire manufacturer in
order to find out the maximum speed.
If a service specification is available, the
maximum speed is limited according to the
speed index in the service specification.
Example: 245/40 ZR 18 97 Y. In this
example, "97 Y" is the service specification.
The letter "Y" represents the speed index
and the maximum speed of the tire is
limited to 186 mph (300 km/h).
Every tire that has a maximum speed rating
R
of more than 186 mph (300 km/h) must
have "ZR" in the size description and the
service specification must be given in
brackets. Example: 275/40 ZR 18 (99 Y).
The speed index "(Y)" shows that the
maximum speed of the tire is above
186 mph (300 km/h). Ask the tire
manufacturer to find out the maximum
speed.
All-weather tires and winter tires
Index Speed rating
21 up to 100 mph (160 km/h)
Q M+S
21 up to 118 mph (190 km/h)
T M+S