Light Truck (LT-Metric) Tire:A tire used on light duty
trucks and some multipurpose passenger vehicles.
Load Index:An assigned number ranging from 1 to 279
that corresponds to the load carrying capacity of a tire.
Maximum In ation Pressure:The maximum air
pressure to which a cold tire may be in ated. The
maximum air pressure is molded onto the sidewall.
Maximum Load Rating:The load rating for a tire at the
maximum permissible in ation pressure for that tire.
Maximum Loaded Vehicle Weight:The sum of curb
weight; accessory weight; vehicle capacity weight;
and production options weight.
Normal Occupant Weight:The number of occupants a
vehicle is designed to seat multiplied by 150 lbs (68 kg).
SeeLoading Your Vehicle on page 4-31.
Occupant Distribution:Designated seating positions.
Outward Facing Sidewall:The side of an
asymmetrical tire that has a particular side that faces
outward when mounted on a vehicle. The side of the
tire that contains a whitewall, bears white lettering
or bears manufacturer, brand, and/or model name
molding that is higher or deeper than the same moldings
on the other sidewall of the tire.Passenger (P-Metric) Tire:A tire used on passenger
cars and some light duty trucks and multipurpose
vehicles.
Recommended In ation Pressure:Vehicle
manufacturer’s recommended tire in ation pressure and
shown on the tire placard. SeeIn ation - Tire Pressure
on page 5-57andLoading Your Vehicle on page 4-31.
Radial Ply Tire:A pneumatic tire in which the ply cords
that extend to the beads are laid at 90 degrees to the
centerline of the tread.
Rim:A metal support for a tire and upon which the tire
beads are seated.
Sidewall:The portion of a tire between the tread and
the bead.
Speed Rating:An alphanumeric code assigned to a
tire indicating the maximum speed at which a tire
can operate.
Traction:The friction between the tire and the road
surface. The amount of grip provided.
Tread:The portion of a tire that comes into contact
with the road.
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Check Tire Pressure System
Your vehicle may have a check tire pressure system
that can alert you to a large change in the pressure of
one tire. The system won’t alert you before you drive
that a tire is low or at. You must begin driving before
the system will work properly.
The LOW TIRE PRESSURE HOLD SET TO RESET
message will appear on the Driver Information Center
(DIC) and the LOW TIRE PRESSURE message
will come on the message center if pressure difference,
or low pressure, is detected in one tire. In the following
conditions, the LOW TIRE PRESSURE message
may not come on even if the tire pressure is low, or it
may come on when the tire pressure is actually normal:
More than one tire is low
Only one tire is replaced with a new tire during service
The vehicle is moving faster than 70 mph (113 km/h)
The system is not yet calibrated
The tire treadwear is uneven
The compact spare tire is installed
Tire chains are being used
The vehicle is being driven on a rough or frozen roadIf the anti-lock brake system warning light comes on,
the check tire pressure system may not be working
properly. See your dealer for service. Also, see
Anti-Lock Brake System Warning Light on page 3-45.
The check tire pressure system detects differences in
tire rotation speeds that are caused by changes in tire
pressure. The system can alert you about a low tire – but
it does not replace normal tire maintenance. SeeTires
on page 5-51.
When the LOW TIRE PRESSURE HOLD SET TO
RESET message appears on the Driver Information
Center and the LOW TIRE PRESSURE message comes
on the message center, you should stop as soon as
you can and check all your tires for damage. If a tire is
at, seeIf a Tire Goes Flat on page 5-69. Also check
the tire pressure in all four tires as soon as you can.
SeeIn ation - Tire Pressure on page 5-57.
Any time you adjust a tire’s pressure or have one or
more tires repaired or replaced, you’ll need to reset, or
calibrate, the check tire pressure system. You’ll also need
to reset the system whenever you rotate the tires, buy
new tires and install or remove the compact spare.
Do not reset the check tire pressure system without
rst correcting the cause of the problem and checking
and adjusting the pressure in all four tires. If you
reset the system when the tire pressures are incorrect,
the check tire pressure system will not work properly
and may not alert you when a tire is low or high.
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Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this may
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability and
resistance to rollover. Additionally, if your vehicle
has electronic systems such as, antilock brakes; traction
control; and electronic stability control, the performance
of these systems can be affected.
{CAUTION:
If you add different sized wheels, your
vehicle may not provide an acceptable level
of performance and safety if tires not
recommended for those wheels are selected.
You may increase the chance that you will
crash and suffer serious injury. Only use
GM speci c wheel and tire systems developed
for your vehicle, and have them properly
installed by a GM certi ed technician.
SeeBuying New Tires on page 5-62andAccessories
and Modi cations on page 5-3for additional information.
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.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
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