2005 Jeep Grand Cherokee Owner Manual - Page 267

STARTING AND OPERATING 267 Tread Wear Indicators These indicators are narrow strips 1/16 inch (1.6 mm) thick and are found in the tread pattern grooves. When the tread pattern is worn down to these treadwear indicators, the tires should be replaced. Replacement Tires The tires on your new vehicle provide a balance of many characteristics. They should be inspected regularly for wear and correct inflation pressure. The manufacturer strongly recommends that you use tires equivalent to the originals in quality and performance when replacement is needed (see section on tread wear indicators). Failure to use equivalent replacement tires may adversely affect the safety, handling, ride and fuel economy of your vehicle. We recommend that you contact your original equipment tire dealer on any questions you may have on tire specifications or capability. 5 Overloading your vehicle, long trips in very hot weather, and driving on bad roads may result in greater wear.