wheel size GMC SIERRA 2005 Owner's Manual

If you will be pulling a trailer that, when loaded, will
weigh more than 5,000 lbs (2 270 kg) be sure to use a
properly mounted weight-distributing hitch and sway
control of the proper size. This equipment is very
important for proper vehicle loading and good handling
when driving. Always use a sway control if the trailer
will weigh more than these limits. You can ask a
hitch dealer about sway controls.
Fifth Wheel and Gooseneck Trailering
Fifth wheel and gooseneck trailers can be used
with many pickup models. These trailers place a
larger percentage of the weight (kingpin weight)
on the tow vehicle than conventional trailers. Make
sure this weight does not cause the vehicle to
exceed GAWR or GVWR.
Fifth wheel or gooseneck kingpin weight should be
15 to 25 percent of the trailer weight up to the maximum
amount specied in the trailering chart for your vehicle.
See “Weight of the Trailer” in this section for more
information.The hitch should be located in the pickup bed so that its
centerline is over or slightly in front of the rear axle.
Take care that it is not so far forward that it will contact
the back of the cab in sharp turns. This is especially
important for short box pickups. Trailer pin box
extensions and sliding fth wheel hitch assemblies can
help this condition. There should be at least
six inches of clearance between the top of the pickup
box and the bottom of the trailer shelf that extends over
the box.
Make sure the hitch is attached to the tow vehicle frame
rails. Do not use the pickup box for support.
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{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. SeeLoading Your
Vehicle on page 4-50.
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. SeeInflation - Tire
Pressure on page 5-79.
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.
20-Inch Tires
If your vehicle has the optional 20-inch P275/55R20
size tires, they are classied as touring tires and
are designed for on road use. The low-prole, wide
tread design is not recommended for “off-road” driving
or commercial uses such as snow plowing. See
Off-Road Driving with Your Four-Wheel-Drive Vehicle on
page 4-20andAdding a Snow Plow or Similar
Equipment on page 4-56for additional information.
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(G) Single Tire Maximum Load:Maximum load that
can be carried and the maximum pressure needed
to support that load when used as a single. For
information on recommended tire pressure see
Ination - Tire Pressure on page 5-79andLoading
Your Vehicle on page 4-50.
Tire Size
The following examples show the different parts of
a 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.
(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letters LT as
the rst two characters in the tire size means a light
truck 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 75, as shown in item C of the
light truck (LT-Metric) tire illustration, it would mean
that the tire’s sidewall is 75% 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:The service description
indicates the load range and speed rating of a tire. The
load index can range from 1 to 279. Speed ratings
range from A to Z. Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
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{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 needed, to get all
the rust or dirt off. SeeChanging a Flat Tire on
page 5-92.
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. SeeLoading Your Vehicle
on page 4-50, for more information about this
Certication/Tire label and where it can be found on
your vehicle.
The tires installed on your vehicle when it was new had a
Tire Performance Criteria Specications (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, load range, 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).
Whenever you 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.
Your vehicle may be equipped with a different
size spare than the road tires (those originally
installed on your vehicle). When new, your
vehicle included a spare tire and wheel
assembly with a similar overall diameter as
your vehicle’s road tires and wheels, so it is all
right to drive on it. Because this spare was
developed for use on your vehicle, it will not
affect vehicle handling.
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Tire Chains
{CAUTION:
If your vehicle has dual wheels or P265/75R16,
LT265/75R16, P265/70R17 or P275/55R20 size
tires, don’t use tire chains. They can damage
your vehicle because there’s 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
CAUTION: (Continued)
CAUTION: (Continued)
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 nd traction devices that will t,
install them on the rear tires.″
Notice:If your vehicle does not have dual wheels
and is equipped with a tire size other than
P265/75R16, LT265/75R16, P265/70R17 or
P275/55R20, use tire chains only where legal and
only when you must. Use chains that are the proper
size for your tires. Install them on the tires of the
rear axle. Don’t use chains on the tires of the front
axle. 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.
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Spare Tire
Your vehicle, when new, had a fully inated spare tire.
A spare tire may lose air over time, so check its
ination pressure regularly. SeeInation - Tire Pressure
on page 5-79andLoading Your Vehicle on page 4-50
for information regarding proper tire ination and loading
your vehicle. For instruction on how to remove, install
or store a spare tire, seeRemoving the Flat Tire
and Installing the Spare Tire on page 5-97andStoring
a Flat or Spare Tire and Tools on page 5-109.
After installing the spare tire on your vehicle, you should
stop as soon as possible and make sure the spare is
correctly inated. Have the damaged or at road
tire repaired or replaced as soon as you can and
installed back onto your vehicle. This way, a spare tire
will be available in case you need it again.
Your vehicle may have a different size spare tire than
the road tires-those originally installed on your vehicle.
This spare tire was developed for use on your
vehicle, so it is all right to drive on it. If your vehicle has
four-wheel drive and the smaller spare is installed,
keep the vehicle in two-wheel drive as much as possible.
If your vehicle has a spare tire that does not match
your vehicle’s original road tires and wheels in size and
type, do not include the spare in the tire rotation.
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 an enclosed 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
Lacquer Thinner
Nail Polish Remover
They can all be hazardous — some more than
others — and they can all damage the vehicle, too.
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