2009 CADILLAC DTS wheel size

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
the Vehicle.................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-7
Filling a Portable Fuel Container.......................5-9
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................................5-17
Automatic Transmission Fluid.........................5-19
Cooling System............................................5-22
Engine Coolant.............................................5-23
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-28Overheated Engine Protection
Operating Mode........................................5-30
Power Steering Fluid.....................................5-31
Windshield Washer Fluid................................5-32
Brakes........................................................5-33
Battery........................................................5-36
Jump Starting...............................................5-38
Headlamp Aiming...........................................5-43
Bulb Replacement..........................................5-46
High Intensity Discharge (HID) Lighting............5-46
Windshield Wiper Blade Replacement..............5-46
Tires..............................................................5-48
Tire Sidewall Labeling...................................5-49
Tire Terminology and Denitions.....................5-54
Ination - Tire Pressure.................................5-57
High-Speed Operation...................................5-59
Tire Pressure Monitor System.........................5-60
Tire Pressure Monitor Operation.....................5-61
Tire Inspection and Rotation...........................5-65
When It Is Time for New Tires.......................5-67
Buying New Tires.........................................5-68
Different Size Tires and Wheels......................5-69
Uniform Tire Quality Grading..........................5-70
Wheel Alignment and Tire Balance..................5-71
Wheel Replacement......................................5-71
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 index and speed rating of the
tire. The load index represents the load carry
capacity a tire is certied to carry. The speed
rating is the maximum speed a tire is certied to
carry a load.
5-53

Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses radio
and sensor technology to check tire pressure levels. The
TPMS sensors monitor the air pressure in your
vehicle’s tires and transmit tire pressure readings to a
receiver located in the vehicle.
Each tire, including the spare (if provided), should be
checked monthly when cold and inated to the ination
pressure recommended by the vehicle manufacturer
on the vehicle placard or tire ination pressure label.
(If your vehicle has tires of a different size than the size
indicated on the vehicle placard or tire ination pressure
label, you should determine the proper tire ination
pressure for those tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one
or more of your tires is signicantly under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires as
soon as possible, and inate them to the proper
pressure. Driving on a signicantly under-inated tire
causes the tire to overheat and can lead to tire failure.
Under-ination also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling
and stopping ability.Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver’s responsibility to
maintain correct tire pressure, even if under-ination has
not reached the level to trigger illumination of the TPMS
low tire pressure telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the system is
not operating properly. The TPMS malfunction indicator
is combined with the low tire pressure telltale. When
the system detects a malfunction, the telltale will
ash for approximately one minute and then remain
continuously illuminated. This sequence will continue
upon subsequent vehicle start-ups as long as the
malfunction exists.
When the malfunction indicator is illuminated, the system
may not be able to detect or signal low tire pressure as
intended. TPMS malfunctions may occur for a variety of
reasons, including the installation of replacement or
alternate tires or wheels on the vehicle that prevent the
TPMS from functioning properly. Always check the TPMS
malfunction telltale after replacing one or more tires or
wheels on your vehicle to ensure that the replacement or
alternate tires and wheels allow the TPMS to continue to
function properly.
SeeTire Pressure Monitor Operation on page 5-61for
additional information.
5-60

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
the Vehicle on page 4-19.Vehicles that have the Tire Pressure Monitor
System (TPMS) will need to have the sensors
reset after a tire rotation is performed. See
Tire Pressure Monitor System on page 5-60.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-103.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after 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. See
Changing a Flat Tire on page 5-74.Five-Tire Rotation Pattern
5-66

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 near the tire
size. 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 5-49for
additional information.
GM recommends replacing tires in sets of four. This is
because uniform tread depth on all tires will help keep
your vehicle performing most like it did when the tires
were new. Replacing less than a full set of tires can affect
the braking and handling performance of your vehicle.
SeeTire Inspection and Rotation on page 5-65for
information on proper tire rotation.{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 5-85.
5-68

{CAUTION:
If you use bias-ply tires on the 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 the 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
could 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. See
Tire Pressure Monitor System on page 5-60.
Your vehicle’s original equipment tires are listed on the
Tire and Loading Information Label. SeeLoading the
Vehicle on page 4-19, for more information about the Tire
and Loading Information Label and its location on your
vehicle.
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, antilock brakes, traction control, and
electronic stability control, the performance of these
systems can be affected.
{CAUTION:
If you add different sized wheels, your vehicle may
not provide an acceptable level of performance and
safety if tires not recommended for those wheels
are selected. You may increase the chance that you
will crash and suffer serious injury. Only use GM
specic wheel and tire systems developed for your
vehicle, and have them properly installed by a GM
certied technician.
SeeBuying New Tires on page 5-68andAccessories
and Modifications on page 5-3for additional information.
5-69

Used Replacement Wheels
{CAUTION:
Putting a used wheel on the vehicle is dangerous.
You cannot know how it has been used or how far
it has been driven. It could fail suddenly and
cause a crash. If you have to replace a wheel, use
a new GM original equipment wheel.
Tire Chains
{CAUTION:
Do not use tire chains. There is not enough
clearance. Tire chains used on a vehicle without
the proper amount of clearance can cause
CAUTION: (Continued)
CAUTION: (Continued)
damage to the brakes, suspension or other vehicle
parts. The area damaged by the tire chains could
cause you to lose control of the vehicle and you or
others may be injured in a crash.
Use another type of traction device only if its
manufacturer recommends it for use on the
vehicle and tire size combination and road
conditions. Follow that manufacturer’s instructions.
To help avoid damage to the vehicle, drive slowly,
readjust or remove the device if it is contacting the
vehicle, and do not spin the vehicle’s wheels. If
you do nd traction devices that will t, install
them on the front tires.
5-73

14. Tighten the wheel nuts rmly in a crisscross
sequence as shown.
If your vehicle is equipped with wheel nut covers,
screw the nut covers on with your ngers, then
tighten one-quarter turn with the wheel wrench.
Notice:Wheel covers will not t on your vehicle’s
compact spare. If you try to put a wheel cover on the
compact spare, the cover or the spare could be
damaged.
Storing a Flat or Spare Tire and
Tools
{CAUTION:
Storing a jack, a tire, or other equipment in the
passenger compartment of the vehicle could
cause injury. In a sudden stop or collision, loose
equipment could strike someone. Store all these in
the proper place.
After you have put the spare tire on your vehicle, store
the at tire in your trunk.
Store the at tire as far forward in the trunk as possible.
Store the jack and wheel wrench in their compartment
in the trunk. For storage, the jack must be raised
until the screw end is ush with the edge of the jack.
The compact spare is for temporary use only. Replace
the compact spare tire with a full-size tire as soon
as you can. 5-Wheel Nuts
8-Wheel Nuts
5-83