2004 CHEVROLET OPTRA tire pressure

Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down. If
one of the wheels is about to stop rolling, the computer
will separately work the brakes at each wheel.The anti-lock system can change the brake pressure
faster than any driver could. The computer is
programmed to make the most of available tire and road
conditions. This can help you steer around the obstacle
while braking hard.
As you brake, your computer keeps receiving updates on
wheel speed and controls braking pressure accordingly.
4-7

Loss of Control
Let us review what driving experts say about what
happens when the three control systems (brakes,
steering and acceleration) do not have enough friction
where the tires meet the road to do what the driver
has asked.
In any emergency, do not give up. Keep trying to steer
and constantly seek an escape route or area of less
danger.
Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid most skids by taking reasonable
care suited to existing conditions, and by not “overdriving”
those conditions. But skids are always possible.
The three types of skids correspond to your vehicle’s
three control systems. In the braking skid, your wheels
are not rolling. In the steering or cornering skid, too much
speed or steering in a curve causes tires to slip and lose
cornering force. And in the acceleration skid, too much
throttle causes the driving wheels to spin.
A cornering skid is best handled by easing your foot off
the accelerator pedalIf your vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want
the vehicle to go. If you start steering quickly enough,
your vehicle may straighten out. Always be ready
for a second skid if it occurs.
Of course, traction is reduced when water, snow, ice,
gravel or other material is on the road. For safety,
you will want to slow down and adjust your driving to
these conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration
or braking (including engine braking by shifting to a
lower gear). Any sudden changes could cause the tires
to slide. You may not realize the surface is slippery
until your vehicle is skidding. Learn to recognize warning
clues — such as enough water, ice or packed snow
on the road to make a “mirrored surface” — and slow
down when you have any doubt.
If you have the anti-lock braking system, remember: It
helps avoid only the braking skid. If you do not have
anti-lock, then in a braking skid (where the wheels are
no longer rolling), release enough pressure on the
brakes to get the wheels rolling again. This restores
steering control. Push the brake pedal down steadily
when you have to stop suddenly. As long as the wheels
are rolling, you will have steering control.
4-13

Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen if the road is wet enough and
you are going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
Hydroplaning does not happen often. But it can if your
tires do not have much tread or if the pressure in
one or more is low. It can happen if a lot of water is
standing on the road. If you can see reflections
from trees, telephone poles or other vehicles, and
raindrops “dimple” the water’s surface, there could be
hydroplaning.
Hydroplaning usually happens at higher speeds. There
just is not a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
Driving Through Deep Standing Water
Notice:If you drive too quickly through deep
puddles or standing water, water can come in
through your engine’s air intake and badly damage
your engine. Never drive through water that is
slightly lower than the underbody of your vehicle. If
you can not avoid deep puddles or standing
water, drive through them very slowly.
Driving Through Flowing Water
{CAUTION:
Flowing or rushing water creates strong forces.
If you try to drive through owing water, as you
might at a low water crossing, your vehicle can
be carried away. As little as six inches of
owing water can carry away a smaller vehicle.
CAUTION: (Continued)
4-18

Before Leaving on a Long Trip
Make sure you are ready. Try to be well rested. If you
must start when you are not fresh — such as after
a day’s work — do not plan to make too many miles that
first part of the journey. Wear comfortable clothing
and shoes you can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it is ready to go. If it needs
service, have it done before starting out. Of course, you
will find experienced and able service experts in GM
dealerships all across North America. They will be ready
and willing to help if you need it.
Here are some things you can check before a trip:
•Windshield Washer Fluid:Is the reservoir full? Are
all windows clean inside and outside?
•Wiper Blades:Are they in good shape?
•Fuel, Engine Oil, Other Fluids:Have you checked
all levels?
•Lamps:Are they all working? Are the lenses clean?
•Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough for
long-distance driving? Are the tires all inflated to the
recommended pressure?
•Weather Forecasts:What is the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
•Maps:Do you have up-to-date maps?
Highway Hypnosis
Is there actually such a condition as “highway hypnosis”?
Or is it just plain falling asleep at the wheel? Call it
highway hypnosis, lack of awareness, or whatever.
There is something about an easy stretch of road with
the same scenery, along with the hum of the tires on the
road, the drone of the engine, and the rush of the
wind against the vehicle that can make you sleepy. Do
not let it happen to you! If it does, your vehicle can
leave the road inless than a second,and you could
crash and be injured.
4-22

Loading Your Vehicle
It is very important to know how much weight your
vehicle can carry. This weight is called the Maximum
Load weight and includes the weight of all occupants,
cargo and all nonfactory-installed options. Two labels on
your vehicle show how much weight it may properly
carry, the Tire and Loading Information label and
the Certification label.
{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
Tire and Loading Information Label
The Tire and Loading Information label shows the
seating capacity and the maximum load your vehicle
can properly carry. The Tire and Loading information
label is either attached to the center pillar below the door
latch or inside of the glove box. This label also lists
your vehicle’s original equipment tire size and the
recommended tire inflation pressure. For more
information on tires and inflation seeTires on page 5-51
andInflation - Tire Pressure on page 5-57.
4-33

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specifications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-14
Engine Air Cleaner/Filter................................5-18
Automatic Transaxle Fluid..............................5-20
Manual Transaxle Fluid..................................5-20
Hydraulic Clutch...........................................5-20
Engine Coolant.............................................5-21
Coolant Surge Tank Pressure Cap..................5-24
Engine Overheating.......................................5-24
Cooling System............................................5-27
Power Steering Fluid.....................................5-33Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-38
Jump Starting...............................................5-39
Headlamp Aiming...........................................5-44
Bulb Replacement..........................................5-44
Halogen Bulbs..............................................5-44
Headlamps..................................................5-44
Front Turn Signal and Parking Lamps..............5-45
Turn Signal Lamps (Side)..............................5-46
Fog Lamps..................................................5-46
Sidemarker Lamps (Front)..............................5-47
Sidemarker Lamps (Rear)..............................5-47
Center High-Mounted Stoplamp (CHMSL).........5-48
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.........................................5-48
Replacement Bulbs.......................................5-49
Windshield Wiper Blade Replacement..............5-50
Tires..............................................................5-51
Inflation - Tire Pressure.................................5-57
Tire Inspection and Rotation...........................5-58
When It Is Time for New Tires.......................5-59
Buying New Tires.........................................5-60
Uniform Tire Quality Grading..........................5-60
Section 5 Service and Appearance Care
5-1

Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your GM Warranty booklet for details. For additional
information refer to the tire manufacturer’s booklet
included with your vehicle’s Owner’s Manual.
{CAUTION:
Poorly maintained and improperly used tires
are dangerous.
Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. See “Loading Your
Vehicle” in the Index.
Underinated tires pose the same danger
as overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
CAUTION: (Continued)
CAUTION: (Continued)

Overinated tires are more likely to be
cut, punctured or broken by a sudden
impact — such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents. If
your tread is badly worn, or if your tires
have been damaged, replace them.
Tire Sidewall Labeling
Useful information about a tire is molded into its
sidewall. The examples below show a typical passenger
car tire and a compact spare tire sidewall.
5-51

(A) Tire Size:The tire size is a combination of letters
and numbers used to define a particular tire’s width,
height, aspect ratio, construction type and service
description. See the “Tire Size” illustration later in this
section for more detail.
(B) Department of Transportation (DOT):The
Department of Transportation (DOT) code indicates that
the tire is in compliance with the U.S. Department of
Transportation Motor Vehicle Safety Standards.
(C) Tire Identication Number (TIN):The letters and
numbers following DOT code are the Tire Identification
Number (TIN). The TIN shows the manufacturer and
plant code, tire size, and date the tire was manufactured.
The TIN is molded onto both sides of the tire, although
only one side may have the date of manufacture.
(D) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(E) Uniform Tire Quality Grading (UTQG):Tire
manufacturers are required to grade tires based on three
performance factors: treadwear, traction and
temperature resistance. For more information see
Uniform Tire Quality Grading on page 5-60.
(F) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. For information on
recommended tire pressure seeInflation - Tire Pressure
on page 5-57andLoading Your Vehicle on page 4-33.
Passenger Car Tire Example
5-52