Buick Enclave: Buying New Tires. Different Size Tires and Wheels. Uniform Tire Quality Grading

Buying New Tires

GM has developed and matched specific tires for the vehicle. The original equipment tires installed on the vehicle were designed to meet the General Motors Tire Performance Criteria Specification, also known as the TPC Spec system rating. When replacement tires are needed, GM strongly recommends buying tires with the same TPC Spec rating.

For the Buick Enclave, the correct tire choice is not based only on size. Tires also influence braking response, steering feel, ride comfort, road noise, traction, stability control operation, and the way the vehicle performs when loaded with passengers or cargo. Choosing tires that match the original specifications helps preserve the driving characteristics that were engineered into the vehicle.

GM's exclusive TPC Spec system considers more than a dozen critical specifications that affect the overall performance of the vehicle. These include brake system performance, ride and handling, traction control, tire pressure monitoring performance, load capability, durability, and other characteristics that are important for safe and predictable operation.

The GM TPC Spec number is molded onto the tire's sidewall near the tire size. If the tires have an all-season tread design, the TPC Spec number will be followed by MS for mud and snow. See Tire Sidewall Labeling  for additional information.

GM recommends replacing all the tires at the same time. Uniform tread depth on all tires will help maintain the performance of the vehicle.

When all four tires have similar tread depth, the vehicle is more likely to maintain balanced traction, stable braking, consistent steering response, and predictable handling. Replacing only one or two tires can create differences in grip, rolling diameter, and wear pattern, which may affect the way the vehicle responds on wet roads, during emergency braking, or when cornering.

Braking and handling performance may be adversely affected if all the tires are not replaced at the same time. See Tire Inspection  and Tire Rotation  for information on proper tire rotation.

WARNING
Tires could explode during improper service. Attempting to mount or dismount a tire could cause injury or death. Only your dealer or authorized tire service center should mount or dismount the tires.

Tire mounting and dismounting require the correct equipment, training, and safety procedures. A tire bead can seat with great force, and incorrect service can cause serious injury. For this reason, tire installation should be handled by a dealer or qualified tire service center.

WARNING
Mixing tires of different sizes, 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 tires on all wheels.

Using mismatched tires can affect traction, braking balance, stability, steering feel, and electronic system behavior. Even when tires appear close in size, differences in construction, tread design, load rating, speed rating, or rolling diameter can change how the vehicle performs.

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.

Radial-ply tires are the proper construction type for this vehicle. They are designed to work with the wheel, suspension, braking system, and vehicle dynamics in a way that bias-ply tires are not. Installing the wrong construction type can reduce safety and may damage wheel components over time.

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, which must be radial, as the original tires.

The replacement tires should also be suitable for the same driving conditions and vehicle use. Tire quality, tread pattern, seasonal rating, load capacity, and performance level should be carefully considered before installation.

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 System.

The Tire and Loading Information label indicates the original equipment tires on the vehicle. See Vehicle Load Limits  for the label location and more information about the Tire and Loading Information label.

Before buying tires for the Buick Enclave, compare the tire size, service description, load index, speed rating, construction type, and TPC Spec information with the vehicle label and the original equipment requirements. Correct tire selection helps maintain safe braking, proper TPMS operation, reliable handling, and comfortable everyday driving.

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 may be affected. This can include braking, ride quality, handling characteristics, steering response, stability, and resistance to rollover.

Different size tires or wheels can also change the relationship between the tire, suspension, brakes, wheel wells, and electronic control systems. Even a small change in tire diameter, width, offset, or load rating may affect how the vehicle operates under normal and emergency conditions.

If the vehicle has electronic systems such as antilock brakes, rollover airbags, traction control, and electronic stability control, the performance of these systems can also be affected. These systems rely on accurate wheel speed, traction, load, and vehicle movement information. Tires or wheels that differ from the recommended specification can interfere with the way these systems respond.

On the Buick Enclave, the tire and wheel package is part of the overall vehicle design. Changing size or type without proper guidance may affect stopping distance, turning clearance, ride comfort, drivetrain operation, TPMS readings, and stability in poor weather or sudden maneuvers.

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.

Wheel and tire changes should be treated as safety-related modifications. The correct combination must provide proper load support, brake clearance, suspension clearance, wheel attachment, tire pressure monitoring compatibility, and predictable handling. Incorrect combinations can create rubbing, vibration, poor fitment, inaccurate speed readings, or reduced stability.

See Buying New Tires  and Accessories and Modifications  for additional information.

Before installing a non-original tire or wheel size, confirm that the parts are approved for the vehicle and that they are installed by a qualified technician. For the Buick Enclave, using the correct GM-specific wheel and tire system is the safest way to maintain the vehicle’s intended performance and protection systems.

Uniform Tire Quality Grading

Quality grades can be found, where applicable, on the tire sidewall between the tread shoulder and the maximum section width. These markings are intended to help compare certain tire performance characteristics, but they should be understood as only one part of tire selection.

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 (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-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.

For the Buick Enclave, UTQG information can help owners compare basic tire characteristics, but it should not replace the vehicle’s required tire size, load rating, speed rating, construction type, and GM-recommended specifications. A tire with attractive grading numbers is not automatically the correct tire for the vehicle if it does not match the proper application.

All passenger car tires must conform to federal safety requirements in addition to these grades.

Treadwear

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. This means the rating is useful for comparison within the test system, but it should not be treated as an exact prediction of how long a tire will last in everyday driving.

The relative performance of tires depends upon the actual conditions of their use and may depart significantly from the norm due to variations in driving habits, service practices, road surfaces, climate, tire pressure maintenance, vehicle loading, alignment condition, and rotation schedule.

A tire with a higher treadwear number may last longer in controlled testing, but real-world tread life can still be shortened by aggressive acceleration, hard braking, high-speed driving, underinflation, overloading, rough pavement, or poor wheel alignment.

Traction – AA, A, B, C

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

This distinction is important because wet-road safety depends on more than straight-line braking. Tread design, tire age, tread depth, inflation pressure, road condition, vehicle speed, and water depth can all affect how the tire performs in real driving. For the Buick Enclave, tires should be selected not only for traction grade, but also for proper fitment and balanced performance in the conditions where the vehicle is used.

Temperature – A, B, C

The temperature grades are A, B, and C, with A being the highest. These grades represent 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. Excessive temperature can also lead to sudden tire failure.

The grade C corresponds to a level of performance that all passenger car tires must meet under the Federal Motor 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.

Heat is one of the major enemies of tire durability. Keeping tires at the recommended cold inflation pressure, avoiding vehicle overloading, and replacing damaged or worn tires on time all help reduce heat-related stress during normal driving.