1994 Buick Roadmaster Owner's Manual - Page 260

After. the tires have been rotated, adjust theand front rear inflation pressure as shown on the Tire-Loading Infomation label. Make certain that wheel nuts are all properly tightened. See "Wheel Nut Torque" in the Index. When It's Time for New Tires One way to tell when it's is time for new tires 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 new tireif: You can see the indicators three or more places at 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 bump, bulge or split. a 258