Optionally,tires with amaximum speed of over
149 mph (240km/h)may have "ZR"inthe
size description, depending on the manufac-
turer (e.g. 245/40ZR18).
Rim diameter: rim diameter ? is the diame-
ter of the bead seat, not the diameter of the
rim flange. The rim diameter is specified in
inches (in).
Load-bearing index: load-bearing index A is
anumerical code that specifies the maximum
load-bearing capacity of atire.
Do not overload the tires by exceeding the
specified load limit. The maximum permissible
load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on
the driver's side (Y page 280).
Example:
Load-bearing index 91 indicates amaximum
load of 1,356 lb (615kg) that the tires can
bear. For further information on the maximum
tire load in kilograms and lbs, see
(Y page 286).
For further information on the load bearing
index, see "Load index" (Y page 286).
Speed rating: speed rating B specifies the
approved maximum speed of the tire.
i
Tire data is vehicle-specific and may devi-
ate from the data in the example.
Regardless of the speed rating, 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)
Summer
tires
Index Speed rating
ZR...(..Y) over 186 mph (300km/h)
ZR over 149 mph (240km/h)
R
Optionally,tires with amaximum speed of
over 149 mph (240 km/h) may have "ZR"in
the size description, depending on the man-
ufacturer (e.g. 245/40ZR18).
The service specification is made up of load-
bearing index A and speed rating B.
R
If the size description of your tire includes
"ZR"and there are no service specifications,
ask the tire manufacturer in order to find
out the maximum speed.
If aservice specification is available, the
maximum speed is limited according to the
speed rating in the service specification.
Example: 245/40ZR18 97 Y. In this exam-
ple, "97 Y" is the service specification. The
letter "Y" represents the speed rating. The
maximum speed of the tire is limited to
186 mph (300 km/h).
R
The size descriptionfor all tires with maxi-
mum speedsofover 186 mph (300 km/h)
must include "ZR", and the service specifi-
cation must be given in parentheses.Exam-
ple: 275/40 ZR 18 (99 Y).Speed rating "(Y)"
indicates that the maximum speed of the
tire is over 186 mph (300 km/h). Ask the
tire manufactureraboutthe maximum
speed.
All-
weather
tires
and win-
ter tires
Index Speed rating
QM+S
1
up to 100 mph (160 km/h)
TM+S
1
up to 118 mph (190 km/h)
HM+S
1
up to 130 mph (210 km/h)
VM+S
1
up to 149 mph (240 km/h)
1
Or M+S i for winter tires.
Allabout wheels and tires
285
Wheelsand tires
Z