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{ Warning

Mixing tires of different sizes (other than those originally installed on

the vehicle), brands, or types may

cause loss of control of the vehicle, resulting in a crash or other vehicle

damage. Use the correct size, brand, and type of tire on all four wheels.


{ Warning

Using bias-ply tires on the

vehicle may cause the wheel rim flanges to develop cracks after

many miles of driving. A tire

and/or wheel could fail suddenly and cause a crash. Use only

radial-ply tires with the wheels on the vehicle.

If the vehicle tires must be

replaced with a tire that does not have a TPC Spec number, make

sure they are the same size, load


range, speed rating, and

construction (radial) as the original tires.

Vehicles that have a tire pressure monitoring system could give an

inaccurate low-pressure warning if non-TPC Spec rated tires are

installed. See Tire Pressure Monitor Operation 0 359.

The Tire and Loading Information label indicates the original

equipment tires on the vehicle. See Vehicle Load Limits 0 211.

Different Size Tires and Wheels

If wheels or tires are installed that are a different size than the original

equipment wheels and tires, vehicle performance, including its braking, ride and handling characteristics,

stability, and resistance to rollover may be affected. If the vehicle has

electronic systems such as antilock brakes, rollover airbags, traction




control, electronic stability control, or All-Wheel Drive, the performance

of these systems can also be affected.


{ Warning

If different sized wheels are used, there may not be an acceptable

level of performance and safety if tires not recommended for those

wheels are selected. This increases the chance of a crash and serious

injury. Only use GM specific wheel and tire systems developed for the vehicle, and have them properly

installed by a GM certified technician.

See Buying New Tires 0 364 and

Accessories and Modifications 0 307.

Uniform Tire Quality Grading

The following information relates to the system developed by the

United States National Highway Traffic Safety Administration

(NHTSA), 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 (UTQG)

system does not apply to deep

tread, winter tires, compact 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.

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

All Passenger Car Tires Must Conform to Federal Safety

Requirements In Addition To These Grades.


The treadwear grade is a

comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. For example, a tire graded

150 would wear one and one-half (1½) times as well on the

government course as a tire graded 100. The relative

performance of tires depends upon the actual conditions of their use, however, and may

depart significantly from the norm due to variations in driving habits, service practices and differences

in road characteristics and climate.



The traction grades, from highest to lowest, are AA, A, B, and C.

Those grades represent the tire's

ability to stop on wet pavement as measured under controlled

conditions on specified

government test surfaces of asphalt and concrete. A tire

marked C may have poor traction performance. Warning: The

traction grade assigned to this tire is based on straight-ahead braking traction tests, and does not

include acceleration, cornering, hydroplaning, or peak traction characteristics.


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