A Tire Performance Criteria (TPC) specification number is molded in the sidewall near the tire size of all original equipment tires. This specification number assures that the tire meets GM's performance standards, including the following aspects:

Usually, a specific TPC number is assigned to each tire size.

Caution: Do not mix different types of tires on the same vehicle such as radial, bias, and bias-belted tires except in an emergency, because the vehicle handling may be seriously affected and may result in loss of control. This caution does not apply to the compact spare that is furnished with the vehicle.

When replacing tires, only use tires that are the same size, load range, and construction as the original tires. This can be easily accomplished by using tires with the same TPC specification number as the original tires. The use of tires of a different size or construction type may seriously affect the ride, handling, speedometer/odometer calibration, vehicle ground clearance, and the tire clearance to the body and chassis. This does not apply to the spare tire furnished with the vehicle.

Install new tires on the same axle in pairs. If you need to replace only 1  tire, pair the replacement tire with the tire that has the most tread. This will equalize braking traction.

Although the tires may appear different in tread design, tires that are built by different manufacturers, but have the identical TPC specification numbers, can be intermixed on the same vehicle.