2008 Jeep Wrangler Owner's Manual - Page 324

STARTING AND OPERATING 323 CAUTION! After inspecting or adjusting the tire pressure always reinstall the valve stem cap. This will prevent moisture and dirt from entering the valve stem, which could damage the Tire Pressure Monitoring Sensor. Inflation pressures specified on the placard are always "cold tire inflation pressure." Cold tire inflation pressure is defined as the tire pressure after the vehicle has not been driven for at least three hours, or driven less than 1 mi (1 km) after a three hour period. The cold tire inflation pressure must not exceed the maximum inflation pressure molded into the tire side wall. Check tire pressures more often if subject to a wide range of outdoor temperatures, as tire pressures vary with temperature changes. 5 Tire Placard Location (Four-Door Models) Tire pressure should be checked and adjusted as well as inspecting for signs of tire wear or visible damage, at least once a month. Use a good quality pocket-type gauge to check tire pressure. Do not make a visual judgement when determining proper inflation. Radial tires may look properly inflated even when they are under inflated.