2009 Dodge Grand Caravan Passenger Owner's Manual - Page 364

362 STARTING AND OPERATING 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 mile (1.6 km) after a three-hour period. The cold tire inflation pressure must not exceed the maximum inflation pressure molded into the tire sidewall. Check tire pressures more often if subject to a wide range of outdoor temperatures, as tire pressures vary with temperature changes. Tire pressures change by approximately 1 psi (7 kPa) per 12° F (7° C) of air temperature change. Keep this in mind when checking tire pressure inside a garage, especially in the Winter. Example: If garage temperature is 68°F (20°C) and the outside temperature is 32°F (0°C), then the cold tire inflation pressure should be increased by 3 psi (21 kPa), which equals 1 psi (7 kPa) for every 12°F (7°C) for this outside temperature condition. Tire pressure may increase from 2 to 6 psi (13 to 40 kPa) during operation. Do not reduce this normal pressure buildup or your tire pressure will be too low. Tire Pressures for High-Speed Operation The manufacturer advocates driving at safe speeds within posted speed limits. Where speed limits or conditions are such that the vehicle can be driven at high speeds, maintaining correct tire inflation pressure is very important. Increased tire pressure and reduced vehicle loading may be required for high-speed vehicle operation. Refer to original-equipment information, or an authorized tire dealer, for recommended safe operating speeds, loading and cold tire inflation pressures.