2006 CADILLAC DTS wheel size

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Oil Life System..................................5-16
Engine Air Cleaner/Filter................................5-18
Automatic Transaxle Fluid..............................5-19
Engine Coolant.............................................5-22
Coolant Surge Tank Pressure Cap..................5-25
Engine Overheating.......................................5-25
Overheated Engine Protection Operating Mode . . .5-27
Cooling System............................................5-28Power Steering Fluid.....................................5-33
Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-37
Jump Starting...............................................5-39
Headlamp Aiming...........................................5-44
Bulb Replacement..........................................5-47
High Intensity Discharge (HID) Lighting............5-47
Windshield Wiper Blade Replacement..............5-47
Tires..............................................................5-49
Tire Sidewall Labeling...................................5-50
Tire Terminology and Denitions.....................5-53
Ination - Tire Pressure.................................5-56
Tire Pressure Monitor System.........................5-59
Tire Inspection and Rotation...........................5-63
When It Is Time for New Tires.......................5-64
Buying New Tires.........................................5-65
Different Size Tires and Wheels......................5-66
Uniform Tire Quality Grading..........................5-67
Wheel Alignment and Tire Balance..................5-69
Wheel Replacement......................................5-69
Tire Chains..................................................5-70
If a Tire Goes Flat........................................5-71
Changing a Flat Tire.....................................5-72
Section 5 Service and Appearance Care
5-1

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.
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.
5-53

Professional Vehicle
The proper ination of the tires on your professional
vehicle depends on the type of tires on it.
If your vehicle has P235/60R17 size tires, the cold
ination pressure is 41 psi (284 kPa).
If your vehicle has LT235/60R17E size tires, the cold
ination pressure depends on the vehicle mass and
should be determined by the vehicle coach-builder.
A tire and loading information label provided by the
nal stage manufacturer should be attached to the
B-pillar on the driver’s side of the vehicle. If the nal
stage manufacturer’s label is not present, the
coach-builder should be consulted. Do not use the
tire pressures indicated on the General Motors label.
These tire pressures are for the incomplete vehicle
and are not the correct tire pressures for the
completed professional vehicle.
Operation at ination pressures below this
recommendation may cause your tires to become
overloaded.
Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) is designed
to monitor the amount of pressure in your vehicle’s
tires using radio and sensor technology. A TPMS
sensor, mounted onto the vehicle’s full-size tire and
wheel assembly, transmits tire pressure readings to a
receiver located in the vehicle. The compact spare
tire and wheel does not have a TPMS sensor.
Tire pressure status and tire pressure warnings are
shown on the Driver Information Center (DIC) display.
For additional information and details about the DIC
operation and displays seeDIC Controls and Displays
on page 3-72andDIC Warnings and Messages on
page 3-76.
If a low tire pressure condition is detected, the TPMS
will display the CHECK TIRE PRESSURE warning
message on the DIC and, at the same time, illuminate
the low tire pressure warning symbol, on the instrument
panel cluster.
You may notice, during cooler weather conditions, that
the low tire pressure warning symbol and the CHECK
TIRE PRESSURE message will display when the vehicle
is rst started and then turn off as you start to drive
the vehicle. This could be an early indicator that the tire
pressures are getting low and need to be checked
and inated to the proper pressure.
5-59

Resetting the TPMS Sensor
Identication Codes
Each TPMS sensor has a unique identication code.
Any time you replace one or more of the TPMS sensors,
rotate the vehicle’s tires, or install a full-size spare
that has a TPMS sensor, the sensor’s identication
codes will need to be matched to the new tire/wheel
position. Each tire/wheel position is matched to
the TPMS sensor using a TPMS diagnostic tool. See
your GM dealer for service.
The TPMS sensors may also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. When increasing the tire’s air pressure,
do not exceed the maximum tire pressure indicated on
the tire’s sidewall.
You will have two minutes to match the rst tire/wheel
position, and ve minutes overall, to match all
four tire/wheel positions. If it takes longer than
two minutes, to match the rst tire and wheel, or
more than ve minutes to match all four tire and wheel
positions the matching process stops and you will
need to start over.The TPMS matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to RUN with the engine off.
3. Press the Driver Information Center (DIC) vehicle
information button until the RELEARN TIRE
POSITIONS displays.
4. Press the set/reset button to allow the system to
learn the tire positions. The horn will sound twice
to indicate that the TPMS is ready, and then
the message TIRE LEARNING ACTIVE will display.
The sensor matching process can begin.
5. Start with the driver’s side front tire.
6. Remove the valve cap from the valve stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for ve seconds,
or until a horn chirp sounds. The horn chirp,
which may take up to 30 seconds, conrms that the
sensor identication code has been matched to
this tire position. To decrease the tire’s air-pressure
use the pointed end of the valve cap, a pencil-style
air pressure gage or a key.
5-61

Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your tires as
soon as possible and check wheel alignment. Also
check for damaged tires or wheels. SeeWhen It Is Time
for New Tires on page 5-64andWheel Replacement
on page 5-69for more information.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The rst rotation
is the most important. SeeScheduled Maintenance
on page 6-4.
If your vehicle has a compact spare tire, it should not be
included in the tire rotation process. Use the four-tire
rotation pattern shown.A ve-tire rotation pattern may be used for your
professional vehicle, if it has a full-size spare tire and
wheel assembly that matches the original equipment
tires and wheels in size, type and brand. The correct
ve-tire rotation pattern is shown.
After the tires have been rotated, adjust the front and
rear ination pressures as shown on the Tire and
Loading Information label. SeeLoading Your Vehicle on
page 4-31.
Vehicles that have the Tire Pressure Monitor System
(TPMS) will need to have the sensors reset after a tire
rotation is performed. SeeTire Pressure Monitor
System on page 5-59. Four-Tire Rotation Pattern
Five-Tire Rotation Pattern
5-63

Make certain that all wheel nuts are properly tightened.
See “Wheel Nut Torque” underCapacities and
Specications on page 5-101.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the vehicle.
In an emergency, you can use a cloth or a
paper towel to do this; but be sure to use a
scraper or wire brush later, if needed, to get all
the rust or dirt off. SeeChanging a Flat Tire on
page 5-72.
When It Is Time for New Tires
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining.
You need a new tire if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
tire’s rubber.
The tread or sidewall is cracked, cut, or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge, or split.
The tire has a puncture, cut, or other damage that
cannot be repaired well because of the size or
location of the damage.
5-64

Buying New Tires
GM has developed and matched specic tires for your
vehicle. The original equipment tires installed on
your vehicle, when it was new, were designed to meet
General Motors Tire Performance Criteria Specication
(TPC spec) system rating. If you need replacement
tires, GM strongly recommends that you get tires with
the same TPC Spec rating. This way, your vehicle
will continue to have tires that are designed to give the
same performance and vehicle safety, during normal
use, as the original tires.
GM’s exclusive TPC Spec system considers over a
dozen critical specications that impact the overall
performance of your vehicle, including brake system
performance, ride and handling, traction control, and tire
pressure monitoring performance. GM’s TPC Spec
number is molded onto the tire’s sidewall by the
tire manufacturer. If the tires have an all-season tread
design, the TPC spec number will be followed by an MS
for mud and snow. SeeTire Sidewall Labeling on
page 5-50for additional information.{CAUTION:
Mixing tires could cause you to lose control of
your vehicle while driving. If you mix tires of
different sizes, brands, or types (radial and
bias-belted tires), the vehicle may not handle
properly, and you could have a crash. Using
tires of different sizes, brands, or types may
also cause damage to your vehicle. Be sure to
use the correct size, brand, and type of tires
on all wheels.
Your vehicle may have a compact spare tire
and wheel assembly. If the vehicle has a
compact spare tire and wheel, they have the
same overall diameter as your vehicle’s
full-size tires and wheels. Because they were
designed and developed for use on your
vehicle, it is all right to drive your vehicle with
the compact spare installed properly. Compact
spare tires are designed for temporary use
only. SeeSpare Tire on page 5-82.
5-65

{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
If you must replace your vehicle’s tires with those that
do not have a TPC Spec number, make sure they
are the same size, load range, speed rating, and
construction type (radial and bias-belted tires) as your
vehicle’s original tires.
Vehicles that have a tire pressure monitoring system
may give an inaccurate low-pressure warning if non-TPC
spec rated tires are installed on your vehicle. Non-TPC
Spec rated tires may give a low-pressure warning
that is higher or lower than the proper warning level you
would get with TPC Spec rated tires. SeeTire
Pressure Monitor System on page 5-59.Your vehicle’s original equipment tires are listed on the
Tire and Loading Information Label. This label is
attached to the vehicle’s center pillar (B-pillar). See
Loading Your Vehicle on page 4-31.
Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this may
affect the way your vehicle performs, including
its braking, ride and handling characteristics, stability,
and resistance to rollover. Additionally, if your
vehicle has electronic systems such as, anti-lock
brakes, traction control, and electronic stability control,
the performance of these systems can be affected.
5-66