1999 GMC SONOMA tires

6-51
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 specified 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 inflated and
not overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory to give you the longest tire life
and best overall performance.Scheduled wheel alignment and wheel balancing are
not needed. However, if you notice unusual tire wear
or your vehicle pulling one way or the other, the
alignment may need to be reset. If you notice your
vehicle vibrating when driving on a smooth road,
your wheels may need to be rebalanced.
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.
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.

6-52
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.
See ªChanging a Flat Tireº in the Index for
more information.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 an accident. If you have to replace a
wheel, use a new GM original equipment wheel.
Tire Chains
NOTICE:
If your vehicle has P235/75R15, P235/70R15,
P235/55R16 or 31x10.50R15LT/C size tires, don't
use tire chains. They can damage your vehicle
because there's not enough clearance.
Use another type of traction device only if its
manufacturer recommends it for use on your
NOTICE: (Continued)

6-53
NOTICE: (Continued)
vehicle and tire size combination and road
conditions. Follow that manufacturer's
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it's contacting your vehicle, and don't
spin your wheels.
If you do find traction devices that will fit,
install them on the rear tires.
If you have other size tires, use tire chains only
where legal and only when you must. Use only SAE
Class ªSº type chains that are the proper size for
your tires. Install them on the drive axle tires
(four
-wheel-drive vehicles can use chains on both
axles) 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.
Appearance Care
Remember, cleaning products can be hazardous. Some
are toxic. Others can burst into flame if you strike a
match or get them on a hot part of the vehicle. Some are
dangerous if you breathe their fumes in a closed space.
When you use anything from a container to clean your
vehicle, be sure to follow the manufacturer's warnings
and instructions. And always open your doors or
windows when you're cleaning the inside.
Never use these to clean your vehicle:

Gasoline

Benzene

Naphtha

Carbon Tetrachloride

Acetone

Paint Thinner

Turpentine

Lacquer Thinner

Nail Polish Remover
They can all be hazardous
-- some more than
others
-- and they can all damage your vehicle, too.

6-58
NOTICE:
Machine compounding or aggressive polishing
on a basecoat/clearcoat paint finish may dull the
finish or leave swirl marks.
Foreign materials such as calcium chloride and other
salts, ice melting agents, road oil and tar, tree sap, bird
droppings, chemicals from industrial chimneys, etc., can
damage your vehicle's finish if they remain on painted
surfaces. Wash the vehicle as soon as possible. If
necessary, use non
-abrasive cleaners that are marked
safe for painted surfaces to remove foreign matter.
Exterior painted surfaces are subject to aging, weather and
chemical fallout that can take their toll over a period of years.
You can help to keep the paint finish looking new by keeping
your vehicle garaged or covered whenever possible.
Cleaning Aluminum Wheels
(If Equipped)
Keep your wheels clean using a soft clean cloth with
mild soap and water. Rinse with clean water. After
rinsing thoroughly, dry with a soft clean towel. A wax
may then be applied.The surface of these wheels is similar to the painted
surface of your vehicle. Don't use strong soaps,
chemicals, abrasive polishes, abrasive cleaners, cleaners
with acid or abrasive cleaning brushes on them because
you could damage the surface. Do not use chrome polish
on any wheels other than chrome
-plated wheels.
Don't take your vehicle through an automatic car wash
that has silicon carbide tire cleaning brushes. These
brushes can also damage the surface of these wheels.
Cleaning Tires
To clean your tires, use a stiff brush with a tire cleaner.
NOTICE:
When applying a tire dressing always take care to
wipe off any overspray or splash from all painted
surfaces on the body or wheels of the vehicle.
Petroleum
-based products may damage the paint
finish and tires.

6-68 Wheels and Tires
Wheel Nut Torque 100 lb-ft (140 N´m) . . . . . . . . . . .
Tire Pressure See the Certification/Tire label.. . . . . .
See ªLoading Your Vehicleº in the Index.
Capacities (Approximate)
Cooling System Capacity*
Engine Quantity
2200 L4 Auto./Manual 11.5 quarts (11.0 L)
ªVORTECº 4300 V6 Auto. 11.7 quarts (11.1 L)
ªVORTECº 4300 V6 Manual 11.9 quarts (11.3 L)
Crankcase Capacity*
Engine Quantity with Filter
2200 L4 4.5 quarts (4.3 L)
ªVORTECº
4300 V64.5 quarts (4.3 L)Automatic Transmission Capacity*
Type Quantity (Drain and Refill)
4L60E 5.0 quarts (4.7 L)
*After refill, the level must be checked.
Differential Fluid
Axle Quantity
Rear 4.0 pints (1.9 L)
Front 2.6 pints (1.2 L)
Fuel Tank Capacity
Type Quantity
Standard Tank 18.5 U.S. gallons (70.0 L)

6-70 Vehicle Dimensions*
Wheelbase
Reg Cab Short Box 108.3 inches (275.1 cm). . . . . .
Reg Cab Long Box 117.9 inches (299.5 cm). . . . . .
Extended Cab 122.9 inches (312.2 cm). . . . . . . . . .
Length
Reg Cab Short Box 189.0 inches (480.1 cm). . . . . .
Reg Cab Long Box 204.9 inches (520.4 cm). . . . . .
Extended Cab 203.6 inches (517.1 cm). . . . . . . . . .
Height
2WD Reg Cab 62.1 inches (157.7 cm). . . . . . . . . . .
2WD Ext Cab 62.2 inches (158.0 cm). . . . . . . . . . .
4WD Reg Cab Short Box 63.8 inches (162.1 cm). .
4WD Reg Cab Long Box 65.4 inches (166.1 cm). .
4WD Extended Cab 63.8 inches (162.1 cm). . . . . .
Width 67.9 inches (172.5 cm). . . . . . . . . . . . . . . . . . Front Tread
2WD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.0 Wheel Offset 54.5 inches (138.4 cm). . . . . . . . .
-6.4 Wheel Offset 55.0 inches (139.6 cm). . . . . . . .
4WD
15
-inch Tires 57.3 inches (145.4 cm). . . . . . . . . . . .
31 x 10.5 Tires 61.2 inches (155.4 cm). . . . . . . . . . .
Rear Tread . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2WD 54.7 inches (138.8 cm). . . . . . . . . . . . . . . . . . . .
4WD
15
-inch Tires 55.1 inches (139.9 cm). . . . . . . . . . . .
31 x 10.5 Tires 59.1 inches (150.0 cm). . . . . . . . . . .
*Figures reflect base equipment only.

Short Trip/City Scheduled Maintenance
7-9
3,000 Miles (5 000 km)

Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.

Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)

Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote **.)
6,000 Miles (10 000 km)

Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.

Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)

Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote **.)

Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE

Short Trip/City Scheduled Maintenance
7-10
9,000 Miles (15 000 km)

Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.

Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)

Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote **.)
12,000 Miles (20 000 km)

Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.

Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)

Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking. (See footnote **.)

Rotate tires. See ªTire Inspection and Rotationº in the Index for proper
rotation pattern and additional information. (See footnote +.)
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE