Nitrogen in tires?

[Sled Dog]

Your tire pressure can have some pretty significant changes throughout the day. In the fall on cold mornings, my Z will have read out at 29 psi in the tires when its 35 degrees, then later in the day when its 70 and sunny, the tires will be 34-35 psi. In the winter, I just fill the tires and check the pressure when its in the mid 20's and i'm good to go