2007 Chrysler PT Cruiser Owner Manual - Page 314

314 STARTING AND OPERATING Tread Wear Indicators Tread wear indicators are in the original equipment tires to help you in determining when your tires should be replaced. Many states have laws requiring tire replacement at this point. Life of Tire The service life of a tire is dependent upon varying factors including but not limited to: • Driving style • Tire pressure • Distance driven WARNING! Tires and spare tire should be replaced after six years, regardless of the remaining tread. Failure to follow this warning can result in sudden tire failure. You could lose control and have an accident resulting in serious injury or death. These indicators are molded into the bottom of the tread grooves. They will appear as bands when the tread depth becomes 1/16 inch (2 mm). When the tread is worn to the tread wear indicators, the tire should be replaced.