Friday, November 30, 2018

How Cold Weather Affects Tire Pressure

Cold Weather Affects Tire Pressure

The lingering chill in the morning air here in the Blue Ridge Mountains is a reminder of the need to check your tire pressure.  The ambient temperature outside directly affects cold tire pressure.

How Does Cold Weather Affect Tire Pressure?

From physics, the ideal gas law states that PV = nRT, where P is absolute pressure, T is absolute temperature, V is the volume (assumed to be relatively constant in the case of a tire), and nR is constant for a given number of molecules of gas.  

In plain English what that means for you is that your tires lose about 1 to 1.5 psi for every 10 degrees of temperature change.

For example, if your tires are at a 32 psi setting on an 85-degree Fahrenheit day in the summer, they will lose 5 to 7.5 psi on a 35-degree Fahrenheit winter morning.

Remember to always check tire pressure when the tires are cold (before the vehicle has been driven for any long distance).