BUICK LACROSSE 2007 Owner's Manual

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.
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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.
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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

If a Tire Goes Flat
It is unusual for a tire to blowout while you are
driving, especially if you maintain your vehicle’s
tires properly. If air goes out of a tire, it is
much more likely to leak out slowly. But if you
should ever have a blowout, here are a few tips
about what to expect and what to do:
If a front tire fails, the at tire will create a drag
that pulls the vehicle toward that side. Take your
foot off the accelerator pedal and grip the
steering wheel rmly. Steer to maintain lane
position, and then gently brake to a stop well out
of the traffic lane.
A rear blowout, particularly on a curve, acts much
like a skid and may require the same correction
you would use in a skid. In any rear blowout
remove your foot from the accelerator pedal. Get
the vehicle under control by steering the way
you want the vehicle to go. It may be very bumpy
and noisy, but you can still steer. Gently brake
to a stop, well off the road if possible.{CAUTION:
Lifting a vehicle and getting under it to
do maintenance or repairs is dangerous
without the appropriate safety equipment
and training. The jack provided with your
vehicle is designed only for changing a
at tire. If it is used for anything else, you
or others could be badly injured or killed
if the vehicle slips off the jack. Use the
jack provided with your vehicle only for
changing a at tire.
If a tire goes at, the next part shows how to
use the jacking equipment to change a at
tire safely.
425

Changing a Flat Tire
If a tire goes at, avoid further tire and wheel
damage by driving slowly to a level place. Turn on
your vehicle’s hazard warning ashers. SeeHazard
Warning Flashers on page 150for more
information.
{CAUTION:
Changing a tire can be dangerous. The
vehicle can slip off the jack and roll over
or fall on you or other people. You and
they could be badly injured or even killed.
Find a level place to change your tire.
To help prevent the vehicle from moving:
1. Set the parking brake rmly.
2. Put the shift lever in PARK (P).
CAUTION: (Continued)
CAUTION: (Continued)
3. Turn off the engine and do not restart
while the vehicle is raised.
4. Do not allow passengers to remain
in the vehicle.
To be even more certain the vehicle will
not move, you should put blocks at the
front and rear of the tire farthest away
from the one being changed. That would
be the tire, on the other side, at the
opposite end of the vehicle.
When your vehicle has a at tire, use the following
example as a guide to assist you in the placement
of wheel blocks.
426

The following information will tell you next how to
use the jack and change a tire.
Removing the Spare Tire and Tools
The equipment you will need is located in the trunk.
1. Open the trunk. SeeTrunk on page 100for
more information.
2. Remove the convenience net if the vehicle
has one.
3. Lift the handle on the spare tire cover. The
handle may hook on the front edge of the
trunk’s weatherstrip to hold the cover out of
the way.
427

4. Turn the wing nut counterclockwise and
remove it.
5. Remove the compact spare tire.6. Turn the nut holding the jack counterclockwise
and remove it. Then remove the jack and
wrench.
428

The tools you will need to change a tire include
the jack (A), extension and protection guide (B),
and wheel wrench (C).
Removing the Flat Tire and
Installing the Spare Tire
You vehicle may have wheels with exposed wheel
nuts. If so, go to the Removing the Wheel Nuts
section. If the vehicle has steel wheel covers with
center caps, the wheel nuts are hidden behind the
cap. To remove the wheel cover, do the following:
1. Remove the center cap by using the at end
of the wheel wrench at the notch on the cap.
Removing the Center Cap
429

2. Use the wheel wrench to loosen the plastic
wheel nut caps, if the vehicle has them, in a
counterclockwise direction.
If needed, nish loosening them by hand.
The nut caps will not come off of the wheel
cover.
3. Use the at end of the wheel wrench and pry
along the edge of the cover until it comes off.
Pull off the wheel cover and set it aside.
The edge of the wheel cover could be sharp,
so do not try to remove the cover with your
bare hands. Do not drop the cap or lay it face
down, as it could become scratched or
damaged.
If the vehicle has aluminum wheels and wheel
center caps, the wheel nuts are hidden behind the
center cap. Remove the center cap by using
the at end of the wheel wrench at the notch.
Do not drop the cap or lay it facedown, as it could
become scratched or damaged.Once you have removed the wheel cover or
center cap, use the following procedure to remove
the at tire and install the spare tire.
1. Place the wheel wrench securely over
the wheel nut. Turn the wheel wrench
counterclockwise to loosen all the wheel
nuts, but do no remove them yet.
2. Turn the jack handle clockwise to raise
the jack lift head.
Removing the Wheel Nuts
430