1993 Pontiac Sunbird Owner's Manual - Page 178

\ TREAD WEAR INDICATORS ~~~~ rire inspection and Rotation T make your tires last longer, have o ;hem inspected and rotated the at nileages recommendedin the Scheduled Maintenance Schedule. See Maintenance Servicesin the Index. Jse this rotation pattern. a e r the tires have been rotated, adjust the front and rear inflation pressureas shown on the Tire-Loading Information label. Makecertain that all wheelnuts sre properly tightened. See Wheel Nut Torque in the Index. When It's Time for New Tires One way to tell whenit's time for new tires isto check the treadwear indicators, which willappear when your tires have only 2x2 inch (1.6 mm) or less of tread remaining. You need a new if: tire You can see the indicators at threeor more places around the tire. You can see cordor fabric showing through the tire's rubber. The tread or sidewallis cracked, cut or snagged deep enough to show cord or fabric. The tire has a bump, bulge split. or The tire has a puncture, cut, or'other damage that can't be repaired well because of the size or location of the damage.