1993 Oldsmobile 88 Owner's Manual - Page 250

Tire Inspection and Rotation To make your tires last longer, have them inspected and rotated at the mileages recommended in your MainteIndex under nance Schedule. See the Scheduled Maintenance Services. Use this rotation pattern. After the tireshave been rotated, adjust the fiont and rear inflation pressure as shown on the Tire-Loading Information all label. Make certain that wheel nuts are properly tightened. See the Index under Wheel Nut Torque. CAUTION A Rust or dirt on a wheel,or on the parts to which is it fastened, can make the wheel nuts become loose after a time. The wheel could come off and cause an accident. When you change a wheel, remove any rustor dirt from places where the wheel attaches to the vehicle. an In emergency, you can use a clothor a paper towel to do this; but be sure to use a scraper wire brush or later, if you need to, to get all the rust or dirt off. See the Index under Changing a Flat Ere. I When It's Time for New Tires One way to tell when it's time for new tires is to check the treadwear indicators, which will appear when your tires have only 2/32 inch (1.6 mm) or less of tread remaining. You need a newtire if You can see the indicators at three places around the tire. You can see cord or fabric 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 bump, bulge or split. The tire has a puncture, cut, other or damage that can't be repaired well because of the size or location of the damage. 249