Tire and Wheel Inspection

WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying TPC SPEC

Courtesy of GENERAL MOTORS CORP.

The tires on all new production models have a tire performance criteria (TPC) rating number molded on the sidewall. The TPC rating will appear as a 4-digit number preceded by the letters TPC SPEC on the tire wall near the tire size. A replacement tire should have the same TPC rating.

Fig 2: Identifying Tire Wear

Courtesy of GENERAL MOTORS CORP.

Inspect the tire and wheel assemblies for the following conditions:

Unusual wear such as cupping, flat spots, and/or heel-and-toe wear These conditions can cause tire growl, tire howl, slapping noises, and/or vibrations throughout the vehicle.
Proper inflation to specifications for the vehicle
Bulges in the sidewalls. Do not confuse bulges, which are an abnormal condition, with normal ply splices which are commonly seen as indentations in the sidewall.
Bent rim flanges