By Roger Marble
I found a chart that covers how to adjust tire pressure when you are inflating tires inside a heated garage (heated to 65° F) when the truck or RV will be moved to a very cold location. I am hoping that when you study the adjustment you will better understand what, if any, adjustment is to be made with your vehicle’s tires under these conditions.
Cold climate pressure correction
Because the air pressure inside a tire will decrease when the vehicle is taken from a warm environment to a cold one, some adjustments may be necessary when adjusting the tire pressures of a vehicle to be operated in very cold temperatures.
These adjustments are only made if the pressures are verified and adjusted inside a heated garage with an air supply that is also at the higher room temperature. (No adjustment necessary if done outside.)
In extreme cases, the following table should be used to help ensure that the operating pressure and deflection of tires are adequate at the outside ambient temperature.
Using the load and pressure charts in the book, determine the appropriate “Recommended Pressure” required for the axle load. Then find the same pressure down the left column of the table [below]. Going across to the relevant outside ambient temperature you will find the corrected inflation pressure to be used.
- A log truck in Alaska has a front axle capacity of 12,000 lbs.
- The truck is equipped with 11R24.5XZY®3 LRG tires.
- The recommended pressure for this fitment is 105 psi.
- The truck is parked overnight in a heated garage.
- The outside high forecasted for today is -20° F.
- The tire pressures are checked and adjusted prior to leaving the heated garage.
- According to the chart, the tires should be adjusted to: 128 psi.