We have previously discussed tire pressure change vs temperature change. The question of tire pressure change due to altitude (elevation) has been brought up on occasion so I guess it’s time to answer that question.
Quick answer: Driving from Death Valley to Denver will result in less than a 3 psi increase in tire pressure IF there are no other changes. So it isn’t a big deal.
Now for the engineers and technically inclined the formula is p = 101325*(1 - 2.25577 * 10**-5 * h)**5.25588 according to info at Engineering Toolbox.
With p (pressure) in Pascals and h (height above sea level) in meters. After unit conversion and if we assume 14.7 psig at sea level we theoretically would have 12.2 psig at 5,000 ft. This decrease in pressure outside the tire would translate to a 2.5 psi increase in the internal tire pressure.
In reality there would be other changes that would also affect your tire pressure as I doubt that you would find the ambient temperature to be the same.
Bottom Line.
If you are checking your tire inflation the morning of every travel day as you should, and adjusting when necessary to meet your minimum inflation as published on your RV tire placard, you will not have any issues as you travel across America, no matter the altitude (elevation) or weather.
Don't forget if you have questions you can submit via email (previously published)
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Post a comment to the June 25 topic "Do you have questions?"
Thanks again for the good info. Roger.
ReplyDeleteAltitude has no effect on tire pressure because altitude is what an airplane flies at. Elevation, on the other hand, will have an effect on tire pressure as discussed in this article. The words altitude/elevation are not synonymous.
ReplyDeletervlovers10100
ReplyDeleteThanks for pointing out the Altitude/Elivation detail. Will try and not to confuse the two in the future
Roger, I know this is an old thread, but as I travel now this comes up. I aired my tires at sea level to 65 psi. But now I am traveling at higher altitudes and they are at 79-71 psi. So I think what you’re saying is I should lower back to 65, cold inflation of course. But if I drop in elevation, don’t I run the risk of being under inflated by as much as 5 psi? I do have a Doran TPMS.
ReplyDelete