Tire Pressure

Start the travel day with the recommended pressures for the weight you are carrying, obtained from the tire manufacturer's load chart. Temperature will greatly affect the pressures in the tires. Cold pressure is measured when the tire hasn't been traveled on for several hours or is cold from the trip. But, if ambient temps are high during the day, the pressure will increase. I'd recommend that the cold pressure be obtained in the morning when it's coolest based on your location, and the tire has not been run for several hours and allowed to cool to ambient temperature. The pressure will increase as the tire temperature increases either due to ambient temps and/or due to friction from running. If you set the proper pressure at ambient temperature BEFORE you start your trip, your pressures will be fine throughout the trip.