2005 Lexus GX 470 Owners Manual - Page 614

CHASSIS CHECKING AND REPLACING TIRES When to replace your tires The tires on your Lexus have built-in tread wear indicators to help you know when the tires need replacement. When the tread depth wears to 1.6 mm (0.06 in.) or less, the indicators will appear. If you can see the indicators in two or more adjacent grooves, the tire should be replaced. The effectiveness of snow tires is lost if the tread wears down below 4 mm (0.16 in.). If you have tire damage such as cuts, splits, cracks deep enough to expose the fabric, or bulges indicating internal damage, the tire should be replaced. " 1 3 New tread Worn tread 2 Tread wear indicator If a tire often goes flat or cannot be properly repaired due to the size or location of a cut or other damage, it should be replaced. If you are not sure, consult with your Lexus dealer. If air loss occurs while driving, do not continue driving. Driving even a short distance can damage a tire beyond repair. Any tires which are over 6 years old must be checked by a qualified technician even if damage is not obvious. Tires deteriorate with age even if they have never or seldom been used. Replace the tires when the tread wear indicators show. The location of the tread wear indicators is shown by the marks such as "TWI" or "∆" marks, etc., molded on the sidewall of each tire. 589