wheel size CHEVROLET OPTRA 2004 1.G Owners Manual

Tire Size
The following illustration shows an example of a typical
passenger car tire size.
(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter “P” as
the first 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 “70,” as shown in item “C”
of the illustration, it would mean that the tire’s sidewall
is 70% 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 the speed rating of a tire. The
load range represents the load carry capacity a tire is
certified to carry. The speed rating is the maximum
speed a tire is certified to carry a load. Speed ratings
range from “A” to “Z”.
5-54

Don’t include the compact spare tire in your tire rotation.
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the tire and loading
information label. Make certain that all wheel nuts are
properly tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-90.
{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. See “Changing a Flat
Tire” in the Index.
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.
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.
5-59

Buying New Tires
To find out what kind and size of tires you need, look at
the Tire-Loading Information label.
Make sure the replacements 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. See “Compact Spare
Tire” in the index.
{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.
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, 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
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.
5-60

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 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.
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 flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
5-63

Storing the 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.
Store the compact spare tire in the compact spare tire
compartment. Place the compact spare tire in the
compartment, then secure the retainer. Store the jack in
its housing in the cargo area. Secure the jack by
turning the retainer clockwise. Store the tools securely
in the foam tray and place the tray on top of the
tire. Replace the trim cover.
The compact spare tire 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 5-72.
Compact Spare Tire
Although the compact spare tire was fully inflated when
your vehicle was new, it can lose air after a time.
Check the inflation 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 inflated. The compact spare
is made to perform well at speeds up to 50 mph
(80 km/h), so you can finish your trip and have your
full-size tire repaired or replaced where you want.
Of course, it is 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, don’t
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.
Do not use your compact spare on other vehicles.
And do not mix your compact spare tire or wheel with
other wheels or tires. They will not fit. Keep your
spare tire and its wheel together.
Notice:Tire chains won’t t your compact spare.
Using them can damage your vehicle and can
damage the chains too. Don’t use tire chains on
your compact spare.
5-72

Short Trip/City Intervals..................................... 6-5
Short Trip/City Scheduled Maintenance................ 6-6
Shoulder Belt Height Adjuster...........................1-18
Skidding........................................................4-13
Some Other Rainy Weather Tips.......................4-19
Special Fabric Cleaning Problems.....................5-74
Specifications, Capacities.................................5-90
Speed Sensitive Power Steering (SSPS)
Warning Light.............................................3-31
Speedometer..................................................3-27
Starter Switch Check.......................................6-20
Starting Your Engine...............................2-19, 2-20
Steering.......................................................... 4-9
Steering in Emergencies..................................4-10
Steering, Suspension and Front Drive Axle Boot
and Seal Inspection.....................................6-23
Steering Tips................................................... 4-9
Steering Wheel, Tilt Wheel................................. 3-5
Storage Areas................................................2-37
Cupholder(s)...............................................2-37
Front Armrest Storage Area...........................2-39
Front Storage Area......................................2-38
Glove Box..................................................2-37
Rear Seat Armrest.......................................2-39
Sunglasses Storage Compartment..................2-38
Storing the Flat Tire and Tools..........................5-71
Storing the Spare Tire and Tools.......................5-72Stuck in Sand, Mud, Ice or Snow......................4-30
Sun Visors.....................................................2-16
Sunglasses Storage Compartment.....................2-38
Sunroof.........................................................2-39
T
Tachometer....................................................3-27
Taillamps
Turn Signal, Stoplamps and Back-up Lamps......5-48
Theft-Deterrent, Radio.....................................3-51
Theft-Deterrent System....................................2-16
Theft-Deterrent Systems...................................2-16
Throttle System Inspection...............................6-24
Tilt Wheel........................................................ 3-5
Time .............................................................3-18
Tire Inflation Check.........................................6-18
Tire Sidewall Labeling......................................5-51
Tire Size.......................................................5-54
Tire Terminology and Definitions........................5-55
Tires.............................................................5-51
Buying New Tires........................................5-60
Chains.......................................................5-63
Changing a Flat Tire....................................5-64
Compact Spare Tire.....................................5-72
If a Tire Goes Flat.......................................5-63
12