width CADILLAC DTS 2008 1.G Owners Manual

Q:What is wrong with this?
A:The belt is twisted across the body.
{CAUTION:
You can be seriously injured by a twisted belt.
In a crash, you would not have the full width of
the belt to spread impact forces. If a belt is
twisted, make it straight so it can work
properly, or ask your dealer/retailer to x it.
1-23

To adjust the vertical aim:
1. Open the hood. SeeHood Release on page 5-12
for more information.
2. Find the center line running through the lens of the
headlamp.
3. Record the distance from the ground to the center
line running through the lens of the headlamp.4. At a wall, measure from the ground upward (A) to
the recorded distance from Step 3 and mark it.
5. Draw or tape a horizontal line (B) the width of the
vehicle at the wall where it was marked in Step 4.
Notice:Do not cover a headlamp to improve beam
cut-off when aiming. Covering a headlamp may
cause excessive heat build-up which may cause
damage to the headlamp.
6. Turn on the low-beam headlamps and place a
piece of cardboard or equivalent in front of the
headlamp not being aimed. This should allow
only the beam of light from the headlamp being
aimed to be seen on the at surface.
5-48

Tire Sidewall Labeling
Useful information about a tire is molded into its
sidewall.
(A) Tire Size
:The tire size is a combination of
letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction type
and service description. See the “Tire Size”
illustration later in this section for more detail.(B) TPC Spec (Tire Performance Criteria
Specication)
:Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications meet or exceed all
federal safety guidelines.
(C) DOT (Department of Transportation)
:The Department of Transportation (DOT) code
indicates that the tire is in compliance with the U.S.
Department of Transportation Motor Vehicle
Safety Standards.
(D) Tire Identication Number (TIN)
:The letters
and numbers following the DOT code are the Tire
Identication Number (TIN). The TIN shows the
manufacturer and plant code, tire size, and date the
tire was manufactured. The TIN is molded onto both
sides of the tire, although only one side may have
the date of manufacture.
(E) Tire Ply Material
:The type of cord and
number of plies in the sidewall and under the tread.
(F) Uniform Tire Quality Grading (UTQG)
:Tire
manufacturers are required to grade tires based on
three performance factors: treadwear, traction and
temperature resistance. For more information see
Uniform Tire Quality Grading on page 5-74.Passenger Car Tire Example
5-53

(G) Maximum Cold Ination Load Limit:Maximum load that can be carried and the
maximum pressure needed to support that load.
For information on recommended tire pressure
seeInflation - Tire Pressure on page 5-60
andLoading the Vehicle on page 4-20.
(A) Temporary Use Only
:The compact
spare tire or temporary use tire has a tread life of
approximately 3,000 miles (5 000 km) and should
not be driven at speeds over 65 mph (105 km/h).The compact spare tire is for emergency use when
a regular road tire has lost air and gone at. See
Spare Tire on page 5-89andIf a Tire Goes Flat on
page 5-78.
(B) Tire Ply Material
:The type of cord and
number of plies in the sidewall and under the tread.
(C) Tire Identication Number (TIN)
:The Tire
Identication Number (TIN). The TIN shows
the manufacturer and plant code, tire size, and
date the tire was manufactured. The TIN is molded
onto both sides of the tire, although only one
side may have the date of manufacture.
(D) Maximum Cold Ination Load Limit
:Maximum load that can be carried and the
maximum pressure needed to support that load.
SeeInflation - Tire Pressure on page 5-60
andLoading the Vehicle on page 4-20.
(E) Tire Ination
:The temporary use tire or
compact spare tire should be inated to 60 psi
(420 kPa). For more information on tire pressure
and ination seeInflation - Tire Pressure on
page 5-60andSpare Tire on page 5-89.
(F) Tire Size
:A combination of letters and
numbers dene a tire’s width, height, aspect
ratio, construction type and service description.
The letter T as the rst character in the tire
size means the tire is for temporary use only.Compact Spare Tire Example
5-54

(G) TPC Spec (Tire Performance Criteria
Specication):Original equipment tires designed
to GM’s specic tire performance criteria have a
TPC specication code molded onto the sidewall.
GM’s TPC specications meet or exceed all federal
safety guidelines.
(A) Tire Size
:The tire size code is a combination
of letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction
type and service description. See the “Tire Size”
illustration later in this section for more detail.(B) TPC Spec (Tire Performance Criteria
Specication)
:Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications meet or exceed all
federal safety guidelines.
(C) Dual Tire Maximum Load
:Maximum load
that can be carried and the maximum pressure
needed to support that load when used in a dual
conguration.
(D) DOT (Department of Transportation)
:The Department of Transportation (DOT) code
indicates that the tire is in compliance with the U.S.
Department of Transportation Motor Vehicle
Safety Standards.
(E) Tire Identication Number (TIN)
:The letters
and numbers following DOT code are the Tire
Identication Number (TIN). The TIN shows the
manufacturer and plant code, tire size, and date the
tire was manufactured. The TIN is molded onto both
sides of the tire, although only one side may have
the date of manufacture.
(F) Tire Ply Material
:The type of cord and
number of plies in the sidewall and under the tread.
Light Truck Tire Example
5-55

(G) Single Tire Maximum Load:Maximum load
that can be carried and the maximum pressure
needed to support that load when used as a single.
For information on recommended tire pressure see
Inflation - Tire Pressure on page 5-60.
Tire Size
The following illustration shows an example of a
tire size.
(A) P-Metric Tire
:The United States version of
a metric tire sizing system. The letter P as the
rst character in the tire size means a passenger
vehicle tire engineered to standards set by the
U. S. Tire and Rim Association.
(B) Tire Width
:The three-digit number indicates
the tire section width in millimeters from sidewall
to sidewall.(C) Aspect Ratio
:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is 60,
as shown in item C of the illustration, it would
mean that the tire’s sidewall is 60 percent as
high as it is wide.
(D) Construction Code
:A letter code is used to
indicate the type of ply construction in the tire. The
letter R means radial ply construction; the letter D
means diagonal or bias ply construction; and the
letter B means belted-bias ply construction.
(E) Rim Diameter
:Diameter of the wheel in
inches.
(F) Service Description
:These characters
represent the load range and speed rating of the
tire. The load index represents the load carry
capacity a tire is certied to carry. The load index
can range from 1 to 279. The speed rating is
the maximum speed a tire is certied to carry
a load. Speed ratings range from A to Z.
5-56

Tire Terminology and Denitions
Air Pressure:The amount of air inside the
tire pressing outward on each square inch of
the tire. Air pressure is expressed in pounds
per square inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire’s height
to its width.
Belt
:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.Cold Tire Pressure
:The amount of air pressure
in a tire, measured in pounds per square inch (psi)
or kilopascals (kPa) before a tire has built up heat
from driving. SeeInflation - Tire Pressure on
page 5-60.
Curb Weight
:The weight of a motor vehicle with
standard and optional equipment including the
maximum capacity of fuel, oil, and coolant,
but without passengers and cargo.
DOT Markings
:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN), an
alphanumeric designator which can also identify
the tire manufacturer, production plant, brand,
and date of production.
GVWR
:Gross Vehicle Weight Rating.
SeeLoading the Vehicle on page 4-20.
GAWR FRT
:Gross Axle Weight Rating for the
front axle. SeeLoading the Vehicle on page 4-20.
5-57

Uniform Tire Quality Grading
Quality grades can be found where applicable on
the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA
Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration (NHTSA), which
grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades are
molded on the sidewalls of most passenger car
tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type
snow tires, space-saver, or temporary use
spare tires, tires with nominal rim diameters of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
While the tires available on General Motors
passenger cars and light trucks may vary with
respect to these grades, they must also conform
to federal safety requirements and additional
General Motors Tire Performance Criteria (TPC)
standards.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specied
government test course. For example, a tire
graded 150 would wear one and a half (1.5) times
as well on the government course as a tire
graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signicantly from
the norm due to variations in driving habits, service
practices, and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are
AA, A, B, and C. Those grades represent the tire’s
ability to stop on wet pavement as measured under
controlled conditions on specied government test
surfaces of asphalt and concrete. A tire marked C
may have poor traction performance.
Warning
:The traction grade assigned to this
tire is based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
5-74

Temperature – A, B, C
The temperature grades are A (the highest), B,
and C, representing the tire’s resistance to the
generation of heat and its ability to dissipate heat
when tested under controlled conditions on a
specied indoor laboratory test wheel. Sustained
high temperature can cause the material of the
tire to degenerate and reduce tire life, and
excessive temperature can lead to sudden tire
failure. The grade C corresponds to a level of
performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety
Standard No. 109. Grades B and A represent
higher levels of performance on the laboratory
test wheel than the minimum required by law.
Warning
:The temperature grade for this tire
is established for a tire that is properly inated
and not overloaded. Excessive speed,
underination, or excessive loading, either
separately or in combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned and
balanced carefully at the factory to give you the longest
tire life and best overall performance. Adjustments to
wheel alignment and tire balancing will not be necessary
on a regular basis. However, if you notice unusual tire
wear or your vehicle pulling to one side or the other, the
alignment might need to be checked. If you notice your
vehicle vibrating when driving on a smooth road, the tires
and wheels might need to be rebalanced. See your
dealer/retailer for proper diagnosis.
Wheel Replacement
Replace any wheel that is bent, cracked or badly rusted
or corroded. If wheel nuts keep coming loose, the wheel,
wheel bolts and wheel nuts should be replaced. If the
wheel leaks air, replace it. Some aluminum wheels can
sometimes be repaired. See your GM dealer/retailer if
any of these conditions exist.
Your GM dealer/retailer will know the kind of wheel
you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
5-75