Tire pressure when traveling

N-Trouble wrote:

Tom N wrote:

N-Trouble wrote:

You can use nitrogen in your tires if it makes you feel better as it is more stable than oxygen and will not raise the PSI as much as it heats.

???

Under equal pressures, all gases expand at the same rate. A gas expands by the same proportion as the temperature rises, provided external pressure remains the same.

True however nitrogen is a "dry" gas unlike oxygen which contains moisture, and as a result will not see as dramatic changes in PSI with temperature. This is one of the biggest reasons racers use nitrogen for consistent PSI across varying temps.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=191

Still not correct. ALL bottled gasses are dry whether they be nitrogen, oxygen, argon or just about anything else. Pure gasses by themselves DO NOT contain any moisture. AIR, which is mostly nitrogen/oxygen is what contains water vapor, and even that can be almost dry if run through a refrigerated air dryer.

N-Trouble wrote:

Tom N wrote:

N-Trouble wrote:

You can use nitrogen in your tires if it makes you feel better as it is more stable than oxygen and will not raise the PSI as much as it heats.

???

Under equal pressures, all gases expand at the same rate. A gas expands by the same proportion as the temperature rises, provided external pressure remains the same.

True however nitrogen is a "dry" gas unlike oxygen which contains moisture, and as a result will not see as dramatic changes in PSI with temperature. This is one of the biggest reasons racers use nitrogen for consistent PSI across varying temps.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=191

exactly why Nitrogen is used in race car tires (nascar). I live in the desert and even in summer they are always @ 80psi cold.

I'm going to put helium in my tires.

Pros:
Lighter scales weights
A smooth floating ride
less impact from "road craters"

Cons:
The Hindenberg

Tom N wrote:

N-Trouble wrote:

You can use nitrogen in your tires if it makes you feel better as it is more stable than oxygen and will not raise the PSI as much as it heats.

???

Under equal pressures, all gases expand at the same rate. A gas expands by the same proportion as the temperature rises, provided external pressure remains the same.

True however nitrogen is a "dry" gas unlike oxygen which contains moisture, and as a result will not see as dramatic changes in PSI with temperature. This is one of the biggest reasons racers use nitrogen for consistent PSI across varying temps.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=191

When we say checking the psi cold, according to tire manufacturer that is at 70 degrees. Colder temp equates to lower psi, and warmer is higher psi.

N-Trouble wrote:

You can use nitrogen in your tires if it makes you feel better as it is more stable than oxygen and will not raise the PSI as much as it heats.

???

Under equal pressures, all gases expand at the same rate. A gas expands by the same proportion as the temperature rises, provided external pressure remains the same.

As said ABSOLUTELY NORMAL.

And, Nitrogen will give you VERY little over using DRY, repeat DRY air. Both follow the same gas laws (change in PSI with change in temperature).

But, use those cheap coin operated air compressors at 7-11's that have no dryer and as any first year physics student can tell you, water and water vapor do NOT follow the same laws-- their PSI change with temperature is quite a lot more than for either dry air or Nitrogen.

Nitrogen in tires is an overrated expensive product that gives no real value

Tires warm up when rolling due to friction and internal flexing and such, and the air pressure in them increases in accordance with the gas laws. If the cold inflation pressure is correct for the weight on the tires (which implies that they aren't overloaded), there's nothing to worry about. Indeed, that's the main reason why tire pressures are measured and checked with the tires cold: the readings change with the temperature, and it's practically impossible to reliably get the same operating conditions to check them warm. Also, since underinflated tires run warmer than properly inflated tires at speed, it's possible at times for underinflated tires to have a higher warm pressure than properly inflated ones.

The (cold) pressure will change somewhat due to changes in ambient temperature, and should of course be adjusted as necessary to compensate.

Your fine. Max PSI on tire label is COLD so its expected that PSI will rise with temp.

You can use nitrogen in your tires if it makes you feel better as it is more stable than oxygen and will not raise the PSI as much as it heats.