Effect of Altitude on Tire Air Pressureby Milton Kazmeyer
Keeping your tires properly inflated reduces wear and tear on your car and saves gas. Unfortunately, any substantial change in altitude can affect your tire pressure and lead to problems.
Air pressure is measured in pounds per square inch, or psi. Air pressure is 14.7 psi at sea level and decreases as you ascend.
If you inflate your tires at sea level, the air inside is pressing against 14.7 psi from the air outside. At higher altitudes, the same amount of air will have more pressure because the outside force is reduced.
The result of lower pressure at altitude means that less air will be needed to properly inflate your tires than at sea level, and tires inflated properly at a lower altitude may now be overfilled.
Anytime you experience a substantial change in altitude, you should check your tire psi and adjust accordingly, adding more air when descending and releasing it when moving higher.
It's also important to note that warmer temperatures will cause the air in your tires to expand, increasing the pressure, and colder temperatures will have the opposite effect. Keep this in mind when making adjustments.
- photo_camera Image by Flickr.com, courtesy of Saquan Stimpson