For 1990-2009 cars

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.

#### Tire Wear

(1) | Hard Cornering/Underinflation
(2) | Incorrect Alignment/Lack of Rotation
(3) | Incorrect Alignment/Non-uniform Tire
(4) | Heavy Acceleration/Over inflation
(5) | Wear Indicator

Inspect the tire and wheel assemblies for the following conditions:

• | Unusual wear such as cupping, flat spots, and heel-and-toe wear.

| (These conditions can cause tire growl, howl, slapping noises, and vibrations throughout the vehicle.)

• | Proper inflation

• | Bulges in the sidewalls

| (Do not confuse bulges with normal ply splices, commonly seen as indentations in the sidewall.)

• | Bent rim flanges

By inspecting these characteristics of the tire and wheel assemblies, you may discover the cause of the vibration. The inspection will also provide assurance that the vehicle is safe for road testing.