2004 Lexus SC 430 User Guide - Page 338

CHASSIS 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. Your vehicle is equipped with 245/40ZR18 or 245/40ZR18 93Y tires: Your Lexus has been fitted with specially developed tires which provide exceptional dynamic performance under general road conditions. However your riding comfort may worsen a little and road noise may increase during driving. Riding comfort and road noise with the run-flat tires may be a little worse than that with the standard tires. You may also notice that your tires will wear more rapidly and tire grip performance will be reduced on the snowy and/or icy roads when compared to high aspect ratio tires, etc. Be sure to have snow tires or tire chains on the snowy and/or icy roads and drive carefully with the speed appropriate for road conditions. NOTICE Low profile tire like 245/40ZR18 or 245/40ZR18 93Y may have greater damage than usual tires to its tire wheel when receiving impact from the road surface. Therefore, pay attention to the following. D Be sure to use with proper tire inflation pressure. If the tire inflation pressure is low, the tire may have greater damage. For detailed information about tire inflation pressure, see page 326 or 329. D Avoid driving onto high, sharp-edged objects and other road hazards. Failure to do so can lead to severe tire damage. 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. 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. 344