ask the tire manufacturer in order to find out
the maximum speed.
If a service specification is available, the max-
imum speed is limited according to the speed
rating in the service specification. Example:
245/40 ZR18 97 Y. In this example, "97 Y" is
the service specification. The letter "Y" rep-
resents the speed rating. The maximum
speed of the tire is limited to 186 mph
(300 km/h). R
The size description for all tires with maxi-
mum speeds of over 186 mph (300 km/h)
must include "ZR", and the service specifica-
tion must be given in parentheses. Example:
275/40 ZR 18 (99 Y). Speed rating "(Y)" indi-
cates that the maximum speed of the tire is
over 186 mph (300 km/h). Ask the tire man-
ufacturer about the maximum speed.
All-weather tires and winter tires
Index Speed rating
Q M+S 1
up to 100 mph (160 km/h)
T M+S 1
up to 118 mph (190 km/h)
H M+S 1
up to 130 mph (210 km/h)
V M+S 1
up to 149 mph (240 km/h)
i Not all tires with the M+S marking provide
the driving characteristics of winter tires. In
addition to the M+S marking, winter tires also
have the M snowflake symbol on the tire
wall. Tires with this marking fulfill the require-
ments of the Rubber Manufacturers Associa-
tion (RMA) and the Rubber Association of
Canada (RAC) regarding the tire traction on
snow. They have been especially developed
for driving on snow.
An electronic speed limiter prevents your vehi-
cle from exceeding a speed of 130 mph
(210 km/h).
The speed rating of tires mounted at the factory
may be higher than the maximum speed that the
electronic speed limiter permits.
Make sure that your tires have the required
speed rating, e.g. when buying new tires. The
required speed rating for your vehicle can be
found in the "Tires" section ( Y
page 367). Further information about reading tire data can
be obtained from any qualified specialist work-
shop.
Load index
In addition to the load-bearing index, load
index C may also be imprinted on the sidewall
of the tire. You will find this after the letter that
identifies the speed rating ( Y
page 357).R
If no specification is given: no text (as in the
example above), represents a standard load
(SL) tire R
XL or Extra Load: represents a reinforced tire R
Light Load: represents a light load tire R
C, D, E: represents a load range that depends
on the maximum load that the tire can carry at
a certain pressure
i Tire data is vehicle-specific and may deviate
from the data in the example.
Maximum load rating
Maximum tire load C is the maximum permis-
sible weight for which the tire is approved.
Do not overload the tires by exceeding the
specified load limit. The maximum permissible1
Or M+S M for winter tires. All about wheels and tires 359
Wheels and tires Z
Tire pressure This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. 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 tire pressure The tires are cold: R
if the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and R
if the vehicle has not been driven further than
1 mile (1.6 km)
Tread The part of the tire that comes into contact 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 prevent the tire from coming loose 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 5 lbs (2.3 kg). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used by
a ti re manufacturer to identify tires, for example
fo r a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur-
er'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 capa-
city of a tire. Traction Traction is the result of friction between the tires
and the road surface.
Treadwear indicators Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of
