Altitude effects on Tire Pressure

Anybody up for Boyles Law or even better the modern ideal gas law?

The state of an amount of gas is determined by its pressure, volume, and temperature. The modern form of the equation is:

pV = nRT

where p is the absolute pressure of the gas; V is the volume; n is the amount of substance; R is the gas constant; and T is the absolute temperature.

In SI units, p is measured in pascals; V in cubic metres; n in moles; and T in kelvin. R has the value 8.314472 J?ÀK−1?Àmol−1 in SI units).

The temperature given in the equation of state must be an absolute temperature that begins at absolute zero. In the metric system of units, we must specify the temperature in Kelvin (not degrees Celsius). In the Imperial system, absolute temperature is in Rankine (not degrees Fahrenheit).

walterK75 said:

I started in Toronto and drove to Colorado. In Colorado the 32 psi tire pressure was now reading 50psi.

Click to expand...

Sorry, the only way you could have gained 18psig going to Colorado was if you were in the Space Shuttle orbiting over Colorado !!

How about using nitrogen instead of compressed air??

Just askin'...

I use a mix containing about 78% nitrogen. Seems to work well.

marchyman said:

I use a mix containing about 78% nitrogen. Seems to work well.

Click to expand...

Actually, 32% nitrox works pretty well too, but watch MOD..... 20.9% nitrox works pretty well too. Kinda like the 78% nitrogen mix. .... just sayin'

Lived in Reno / Sparks for years and used to ride down to the California valley and then back up over I-80 and Donner summit at night in VERY cold conditions. Never gave a thought to tire pressure. Too busy trying to stay warm.

marchyman said:

I use a mix containing about 78% nitrogen. Seems to work well.

Click to expand...

I use 78.09% in mine.