2007 BUICK LACROSSE Owner's Manual

{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. SeeChanging a Flat Tire on page 426.
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.
417

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 403for additional information.
418

{CAUTION:
Mixing tires could cause you to lose
control 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. It is all right to drive with your
compact spare temporarily, as it was
developed for use on your vehicle. See
Compact Spare Tire on page 437.
{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.
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). SeeLoading Your Vehicle on page 319,
for more information about the Tire and Loading
Information label and its location on your vehicle.
419

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.{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 418and
Accessories and Modications on page 341for
additional information.
420

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.
421

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 may need to be checked. If you notice
your vehicle vibrating when driving on a smooth
road, your tires and wheels may need to be
rebalanced. See your dealer 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 (except some aluminum wheels,
which can sometimes be repaired). See your
dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
422

Each new wheel should have the same
load-carrying capacity, diameter, width, offset
and be mounted the same way as the one
it replaces.
If you need to replace any of your wheels, wheel
bolts, or wheel nuts, replace them only with
new GM original equipment parts. This way,
you will be sure to have the right wheel, wheel
bolts, and wheel nuts for your vehicle.
{CAUTION:
Using the wrong replacement wheels,
wheel bolts, or wheel nuts on your vehicle
can be dangerous. It could affect the
braking and handling of your vehicle,
make your tires lose air and make you
lose control. You could have a collision
in which you or others could be injured.
Always use the correct wheel, wheel
bolts, and wheel nuts for replacement.Notice:The wrong wheel can also cause
problems with bearing life, brake cooling,
speedometer or odometer calibration,
headlamp aim, bumper height, vehicle ground
clearance, and tire or tire chain clearance
to the body and chassis.
SeeChanging a Flat Tire on page 426for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your 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.
423

Tire Chains
{CAUTION:
If your vehicle has P225/55R17 size tires,
do not use tire chains, there is not
enough clearance.
Tire chains used on a vehicle without the
proper amount of clearance can cause
damage to the brakes, suspension or
other vehicle parts. The area damaged by
the tire chains could cause you to lose
control of your 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 your vehicle and tire size
combination and road conditions.
Follow that manufacturer’s instructions.
CAUTION: (Continued)
CAUTION: (Continued)
To help avoid damage to your vehicle,
drive slowly, readjust or remove the
device if it is contacting your vehicle,
and do not spin your wheels.
If you do nd traction devices that will t,
install them on the front tires.
Notice:If your vehicle has a tire size other
than P225/55R17 size tires, use tire chains only
where legal and only when you must. Use only
SAE Class “S” type chains that are the proper
size for your tires. Install them on the front tires
and tighten them as tightly as possible with the
ends securely fastened. Drive slowly and follow
the chain manufacturer’s instructions. If you
can hear the chains contacting your vehicle,
stop and retighten them. If the contact
continues, slow down until it stops. Driving too
fast or spinning the wheels with chains on will
damage your vehicle.
424