GM's Tire-Wheel Systems Laboratory puts North American-designed tire-wheel assemblies through stringent tests to ensure they meet or exceed internal, federal and Society of Automotive Engineers criteria.
GM's tire and wheel engineers develop exclusive Tire Performance Criteria (TPC) specifications for each vehicle engineered in North America. This helps ensure tire performance, handling and durability under a variety of driving conditions. Major tire manufacturer engineers work together with GM's tire and wheel engineers during the validation process.
Only those select tires approved through GM's TPC process are stamped with a TPC spec number, so customers can go to a dealership or a national tire brand retail store and order a new tire specifically engineered to go with a GM-specific vehicle.
"Tires are an engineering marvel, with 20 individual compounds and components designed to provide the customer with an optimum blend of performance and durability," said Cowger. "Replacing your tires with anything besides the original equipment Tire Performance Criteria-specified tire can impact many performance aspects of a vehicle, including braking, steering, cornering, ride and handling, noise and vibration, traction and even fuel economy."
Basic Tire Maintenance Tips
A few simple tire maintenance steps can help identify and address problems before needing replacement:
• Check for uneven wear or excessive tread wear.
• Make sure all tires, including the spare, are properly inflated. Inflate tires to recommended pressure. Underinflated tires can reduce fuel economy by up to 3.3 percent, according to the U.S. Department of Energy.
• Properly rotate tires at recommended intervals.
• Properly align and balance wheels.
How To Tell
If You Need New Tires
Tire wear depends on several factors, including driving style and tire maintenance habits. One way to know when to replace tires is when tread-wear indicators appear. A tire's built-in tread-wear indicators are "wear bars" that look like narrow strips of smooth rubber across the tread and appear when it's time to replace the tire.
A new tire is needed if:
• The indicators at three or more places around the tire are visible.
• Cord or fabric is 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 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.
Buying New Tires
To determine what kind and size of tire are needed, check the vehicle label. For GM vehicles engineered in North America, the tires installed on each new vehicle have a Tire Performance Criteria Specification (TPC Spec) number on each tire's sidewall. When purchasing new tires, get ones with that same TPC Spec number to ensure the vehicle continues to have tires designed to give proper endurance, handling, speed rating, traction, ride and performance during normal service on the vehicle. If the tires have an all-season tread design, the TPC number will be followed by an "M+S" (for mud and snow).
For more information, visit the GM Goodwrench Web site at www.goodwrench.com.