293 Operation
Tires and wheels
If you want to set new reference values
manually:
Using the Tire and Loading Information
placard on the driver’s door B-pillar
(
page 280) or, if available, the
supplemental tire inflation pressure
information on the inside of the fuel
filler flap (
page 264), make sure the
tire inflation pressure of all four tires is
correct.
Press buttonè orÿ on the mul-
tifunction steering wheel repeatedly
until the standard display menu
appears in the multifunction display.
Press buttonj ork repeatedly
until you see the current inflation
pressures for each tire appear in the
multifunction display or the following
message appears in the multifunction
display:
Tire pressure
displayed
only after
driving for
a few minutes
Press the reset button (page 130).
The following message will appear in
the multifunction display:
Restart
tire pressure
monitor?
Press theæ button.
The following message will appear in
the multifunction display:
Tire pressure
monitor
restarted
After driving a few minutes the system
verifies that the current tire inflation
pressures are within the system’s
specified range. Afterwards the current
tire inflation pressures are accepted as
reference pressures and then moni-
tored.
If you wish to cancel activation:
Press theç button.
iRestart the TPMS after adjusting the tire in-
flation pressure to the inflation pressure recom-
mended for the vehicle operating condition. Tire
pressure should only be adjusted on cold tires.
Observe the recommended tire inflation pres-
sure on the Tire and Loading Information placard
on the driver’s door B-pillar (
page 280). Some
vehicles may have supplemental tire inflation
pressure information for driving at high speeds
(
page 287) or for vehicle loads less than the
maximum loaded vehicle condition
(
page 287). If such information is provided, it
can be found on the inside of the fuel filler flap
(
page 264).
294 Operation
Tires and wheels
Potential problems associated with
underinflated and overinflated tires
Underinflated tires
Underinflated tires can:
cause excessive and uneven tire wear
adversely affect fuel economy
lead to tire failure from being
overheated
adversely affect handling
characteristicsOverinflated tires
Overinflated tires can:
adversely affect handling
characteristics
cause uneven tire wear
be more prone to damage from road
hazards
adversely affect ride comfort
increase stopping distance
Tire labeling
Besides tire name (sales designation) and
manufacturer name, a number of markings
can be found on a tire.
Following are some explanations for the
markings on your vehicle’s tires:
Warning!G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being
overheated.
Warning!G
Follow recommended tire inflation
pressures.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
295 Operation
Tires and wheels
1Uniform Quality Grading Standards
(
page 302)
2DOT, Tire Identification Number (TIN)
(
page 299)
3Maximum tire load (
page 300)
4Maximum tire inflation pressure
(
page 301)
5Manufacturer
6Tire ply material (
page 304)
7Tire size designation, load and speed
rating (
page 295)
8Load identification (
page 298)
9Tire nameTire size designation, load and speed
rating
1Tire width
2Aspect ratio in %
3Radial tire code
4Rim diameter
5Tire load rating
6Tire speed ratingGeneral:
Depending on the design standards used,
the tire size molded into the sidewall may
have no letter or a letter preceding the tire
size designation.
No letter preceding the size designation
(as illustrated above): Passenger car tire
based on European design standards.
Letter “P” preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter “LT” preceding the size designation:
Light Truck tire based on U.S. design
standards.
Letter “T” preceding the size designation:
Temporary spare tires which are high
pressure compact spares designed for
temporary emergency use only.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
For more information, see “Rims and tires”
(
page 416).
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
296 Operation
Tires and wheels
Tire width
The tire width1 (
page 295) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (
page 295) is the
dimensional relationship between tire
section height and section width and is
expressed in percentage. The aspect ratio
is arrived at by dividing section height by
section width.
Tire code
The tire code3 (
page 295) indicates
the tire construction type. The “R” stands
for radial tire type. Letter “D” means
diagonal or bias ply construction; letter “B”
means belted-bias ply construction.
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 ZR 18).
For additional information, see “Tire speed
rating” (
page 297).Rim diameter
The rim diameter4 (
page 295) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating5 (
page 295) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1 356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 300) where the maximum load
associated with the load index is indicated
in kilograms and lbs.
Warning!G
The tire load rating must always be at least
half of the GAWR (
page 305) of your
vehicle. Otherwise, tire failure may be the
result which may cause an accident and/or
serious personal injury to you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
Warning!G
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard located on
the driver’s door B-pillar. Overloading the
tires can overheat them, possibly causing a
blowout. Overloading the tires can also
result in handling or steering problems, or
brake failure.
297 Operation
Tires and wheels
For additional information on tire load
rating, see “Load identification”
(
page 298).
Tire speed rating
The tire speed rating6 (
page 295)
indicates the approved maximum speed
for the tire.Summer tires
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 exam-
ple: 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 the tire load rating5
(
page 295) and the tire speed
rating6 (
page 295).
If your tire includes “ZR” in the size
designation and no service
description5 and6 (
page 295) is
given, the tire manufacturer must be
consulted for the maximum speed
capability.
iTire load rating5 (page 295) and tire
speed rating6 (
page 295) are also referred
to as “service description”.
Warning!G
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
personal injury and possible death, for you
and for others.
iTire load rating5 (page 295) and tire
speed rating6 (
page 295) are also referred
to as “service description”.
IndexSpeed rating
Qup 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)
(Y)above 186 mph (300 km/h)
ZRabove 149 mph (240 km/h)
298 Operation
Tires and wheels
If a service description5 and6
(
page 295) 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).
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 ZR18 (99Y).
The “(Y)” speed rating 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
Load identification
1Load identification
IndexSpeed rating
QM+S1
1or M+S.for winter tires
up to 100 mph (160 km/h)
TM+S1up to 118 mph (190 km/h)
HM+S1up to 130 mph (210 km/h)
VM+S1up to 149 mph (240 km/h)
iNot all M+S rated tires provide special
winter performance. Make sure the tires you use
show M+S and the mountain/snowflake
marking. on the tire sidewall. These tires
meet specific snow traction performance
requirements of the Rubber Manufacturers
Association (RMA) and the Rubber Association
of Canada (RAC) and have been designed
specifically for use in snow conditions.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
299 Operation
Tires and wheels
In addition to tire load rating, special load
identification1 may be molded into the
tire sidewall following the letter designat-
ing the tire speed rating (
page 295).
No specification given: absence of any text
(like in above example) indicates a
standard load (SL) tire.
XL or Extra Load: designates an extra load
(or reinforced) tire.
Light Load: designates a light load tire.
C, D, E: designates load range associated
with the maximum load a tire can carry at
a specified pressure.
DOT, Tire Identification Number (TIN)
U.S. tire regulations require each new tire
manufacturer or tire retreader to mold a
TIN into or onto a sidewall of each tire
produced.
The TIN is a unique identifier which facili-
tates efforts by tire manufactures to notify
purchasers in recall situations or other
safety matters concerning tires and gives
purchasers the means to easily identify
such tires.
The TIN is comprised of “Manufacturer’s
identification mark”, “Tire size”, “Tire type
code” and “Date of manufacture”.1DOT
2Manufacturer’s identification mark
3Tire size
4Tire type code (at the option of the tire
manufacturer)
5Date of manufacture
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
300 Operation
Tires and wheels
DOT (Department of Transportation)
A tire branding symbol1 (
page 299)
which denotes the tire meets require-
ments of the U.S. Department of
Transportation.
Manufacturer’s identification mark
The manufacturer’s identification mark2
(
page 299) denotes the tire
manufacturer.
New tires have a mark with two symbols.
Retreaded tires have a mark with four sym-
bols. For more information on retreaded
tires (
page 277).
Tire size
The code3 (
page 299) indicates the
tire size.Tire type code
The code4 (
page 299) may, at the
option of the manufacturer, be used as a
descriptive code for identifying significant
characteristics of the tire.
Date of manufacture
The date of manufacture5 (
page 299)
identifies the week and year of manufac-
ture.
The first two figures identify the week,
starting with “01” to represent the first full
week of the calendar year. The second two
figures represent the year.
For example, “3202” represents the 32nd
week of 2002.
Maximum tire load
1Maximum tire load rating
The maximum tire load is the maximum
weight the tires are designed to support.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.