wheel size CHEVROLET ASTRO 2005 Owners Manual

Tire Size
The following illustration shows an example of a typical
passenger vehicle tire size.
(A) Passenger (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.
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After the tires have been rotated, adjust the front and
rear ination pressures as shown on the Tire and
Loading Information label. SeeInation - Tire Pressure
on page 5-64andLoading Your Vehicle on page 4-28.
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 you need to, 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’s
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. Some
commercial truck tires
may not have treadwear
indicators.
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
can’t be repaired well because of the size or
location of the damage.
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Buying New Tires
To nd out what kind and size of tires you need, look
at the Certication/Tire label or the Tire and Loading
Information label. SeeLoading Your Vehicle on
page 4-28, for examples of the labels and where they
can be found on your vehicle.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specication (TPC Spec)
number on each tire’s sidewall. When you get new tires,
GM recommends that you get tires with that same
TPC Spec number. That way your vehicle will continue
to have tires that are designed to give proper
endurance, handling, speed rating, traction, ride and
other things during normal service on your vehicle.
If your tires have an all-season tread design, the TPC
number will be followed by an “MS” (for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tires.{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
or types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires on
all wheels. It’s all right to drive with your
compact spare temporarily, it was developed
for use on your vehicle. SeeCompact Spare
Tire on page 5-84.
{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.
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Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can’t know how it’s been used
or how far it’s 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
Notice: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 rear axle 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.
If a Tire Goes Flat
It’s unusual for a tire to “blowout” while you’re driving,
especially if you maintain your tires properly. If air goes
out of a tire, it’s 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.
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3. Put the at end of the extension on an angle
through the hole in the rear door frame, above
the bumper.
The compact spare is for temporary use only.
Replace the compact spare tire with a full-size tire
as soon as you can. SeeCompact Spare Tire
on page 5-84. See the storage instructions label to
restore your compact spare properly.
4. Raise the tire fully against the underside of the
vehicle by turning the ratchet/wheel wrench until
you hear two clicks or feel it skip twice. The spare
tire hoist cannot be overtightened.
5. Make sure the tire is stored securely. Push and
pull (A), and then try to turn (B) the tire. If the tire
moves, use the ratchet/wheel wrench to tighten
the cable.
6. Return the jacking equipment to its proper location.
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Compact Spare Tire
Although the compact spare tire was fully inated when
your vehicle was new, it can lose air after a time.
Check the ination pressure regularly. It should be
60 psi (420 kPa).
After installing the compact spare on your vehicle,
you should stop as soon as possible and make sure
your spare tire is correctly inated. The compact spare
is made to perform well at speeds up to 65 mph
(105 km/h) for distances up to 3,000 miles (5 000 km),
so you can nish your trip and have your full-size
tire repaired or replaced where you want. Of course,
it’s best to replace your spare with a full-size tire as soon
as you can. Your spare will last longer and be in good
shape in case you need it again.
Notice:When the compact spare is installed, do
not take your vehicle through an automatic car
wash with guide rails. The compact spare can get
caught on the rails. That can damage the tire
and wheel, and maybe other parts of your vehicle.
Don’t use your compact spare on other vehicles.
And don’t mix your compact spare tire or wheel with
other wheels or tires. They won’t t. Keep your spare
tire and its wheel together.Notice:Tire chains will not t your compact spare.
Using them can damage your vehicle and can
damage the chains too. Do not use tire chains on
your compact spare.
Appearance Care
Cleaning products can be hazardous. Some are toxic.
Other cleaning products can burst into ames if a match
is struck near them or if they get on a hot part of the
vehicle. Some are dangerous if their fumes are inhaled in
a closed space. When anything from a container is used
to clean the vehicle, be sure to follow the manufacturer’s
warnings and instructions. Always open the doors or
windows of the vehicle when cleaning the inside.
Never use these to clean the vehicle:
Gasoline
Benzene
Naphtha
Carbon Tetrachloride
Acetone
Paint Thinner
Turpentine
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