2003 Toyota Prius Owners Manual - Page 227

D Be sure to reinstall the tire inflation valve caps. Without the valve caps, dirt or moisture could get into the valve core and cause air leakage. If the caps have been lost, have new ones put on as soon as possible. 163.Checking and replacing tires Tread wear indicator 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. 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 Toyota dealer. If an air loss occurs while driving, do not continue driving with a deflated tire. Driving even a short distance can damage a tire beyond repair. 82p004b CHECKING YOUR TIRES Check the tire tread for the tread wear indicators. If the indicators show, replace the tires. The tires on your Toyota 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 lower the tread, the higher the risk of skidding. The effectiveness of snow tires is lost if the tread wears down below 4 mm (0.16 in.). 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. This also applies to the spare tire and tires stored for future use. REPLACING YOUR TIRES When replacing a tire, use only the same size and construction as originally installed and with the same or greater load capacity. 220