2010 Jeep Grand Cherokee Owner Manual SRT8 - Page 275

274 STARTING AND OPERATING Tire Inflation Pressures is defined as the tire pressure after the vehicle has not The proper cold tire inflation pressure is listed on the been driven for at least three hours, or driven less than driver's side "B" Pillar. 1 mile (1.6 km) after a three hour period. The cold tire inflation pressure must not exceed the maximum inflaThe pressure should be checked and adjusted as well as tion pressure molded into the tire side wall. inspecting for signs of tire wear or visible damage at least once a month. Use a good quality pocket-type gauge to Check tire pressures more often if subject to a wide range check tire pressure. Do not make a visual judgement of outdoor temperatures, as tire pressures vary with when determining proper inflation. Radial tires may look temperature changes. properly inflated even when they are under inflated. Tire pressures change by approximately 1 psi (7 kPa) per 12°F (7°C) of air temperature change. Keep this in mind CAUTION! when checking tire pressure inside a garage, especially in After inspecting or adjusting the tire pressure always the Winter. reinstall the valve stem cap. This will prevent moisExample: If garage temperature = 68°F (20°C) and the ture and dirt from entering the valve stem, which outside temperature = 32°F (0°C) then the cold tire could damage the valve stem. inflation pressure should be increased by 3 psi (21 kPa), which equals 1 psi (7 kPa) for every 12°F (7°C) for this Inflation pressures specified on the placard are always outside temperature condition. "cold tire inflation pressure". Cold tire inflation pressure