A little extra service from the Dealer when I visited for my new belts. Now my sensors don't go off any longer because my tires don't have fluctuating tire pressures.

Composition of air (% by volume):

Nitrogen (N2): 78.09%
Oxygen (O2): 20.95%
Argon (Ar): 0.93%
Carbon dioxide (CO2): 0.038%

Others (less than 0.002% each): Neon (Ne), Helium (He), Krypton (Kr), Hydrogen (H2), Xenon (Xe).

 

If you're saying that you filled your tires with nitrogen rather than air, I think you'll find that nitrogen (just like air) will also undergo fluctuations in pressure with temperature. The main reason people would do this is because typical nitrogen cylinders delivered from a local gas service will be moisture free while compressed air typically has a good deal of moisture in it. Nitrogen is commonly used as a "blanket" inside liquid vessels to prevent moisture from contaminating the contents. And since moisture is a common root cause for promoting corrosion of TPMS sensors and the inside surfaces of the metal wheel, some have proposed using nitrogen inside tires as a preventative measure. Good luck and let us know how much (or little) pressure changes you experience.

 

How much was your tire pressure fluctuating that it caused your sensors to go off?? Or do you run at 26 psi or something?

 

The important thing is, you think that made things good. Perception can bring peace of mind.

 

My pressure changes about 3 to 4 lbs from cold to hot using air, If you use Nitrogen you will see less change in pressure. That is why NASCAR uses Nitrogen in the tires to control tire pressure better for the temp changes.

 

good post Bill I learned something thanks

 

Im an aircraft mechanic and we also use Nitrogen in all aircraft tires for this reason and also because at high altitude compressed air tends to expand. Im sure it wont hurt anything if you used 100% nitrogen if you get good dry nitrogen.

 

It wouldn't hurt anything if you get good dry air. Nitrogen does not magically repeal the physical laws of gas behavior, such as a constant volume of gas (interior of a tire, for example) will increase pressure when temperature goes up. http://en.wikipedia.org/wiki/Ideal_gas_law


As far as being an aircraft mechanic, you obviously don't work much with aircraft having pressurized nitrogen vessels, such as brake accumulators. These have a standard pressure at a given temperature (Usually 70F,) but, surprise, surprise, an adjustment for temperature, because nitrogen increases pressure with temperature, like every other gas known to man. It's used in tires because lack of water vapour means no ice formation in the tires at high altitude.

 

Sounds pretty scientific, but it will still deflate...............

 

Time to turn you A&P back to the FAA!

 

Well as far as Nitrogen goes , I havent found a way to get the nitro cart to the parking lot to try it( dont think the Base commander wound like my car on the flightline), But it seems to work good on our T-38's down here!! Before we used Air and they fluxed like crazy, since going to nitro our tires and struts hold better than before so, I think you will be happier? Just have to see?

 

Or, the Dealer just made a easy $40 on me.

 

Did they offer to top off when necessary? For $40 I would think they would. Did they evacuate the 78% nitrogen/21% oxygen that was already in the tire? Just curious what procedure they used.
As far as Nascar using nitrogen, in their case the tires heat up tremendously and a half pound makes a difference in handling at 200 mph. Your tires won't even get hot to the touch, the difference in pressure will be so small that you won't even notice it. Remember, you only replaced 22% of the total with nitrogen.

 

Yes, the Dealership will top off the tires and if I lose the charge from a leak they will replace the nitrogen free.

 

I couldnt put it any better myself...

Yes they do expand, but the pressure differential between sea level and outer space is 14.7 pounds per square inch (psi).

if you was to remove 14.7psi on the outside of the tire, the stresses would be the same if you added 14.7 psi on the inside of the tire.

Most tires can take over inflation of 15psi with no problem.

For aircraft tires there is a larger pressure increase due to heating on landing, (notice big black skid marks on runways). As a gas is heated the pressure increases.

For nitrogen, the theory is that nitrogen is approximately 6 time larger than oxygen, therefore is less likely to leak out or through a tire. Therefore a tire filled will nitrogen will hold the same pressure longer than air. But since air is already approximately 80 percent nitrogen, is the cost justified? Might I add that compressed air or any form of air for that matter contains oxygen. Oxygen is what? Its not only corrosive but will spontaneously combust. Thus the reason many jet powered aircraft has an NIU (Nitrogen Inert unit) that steadily removes oxygen from the fuel tanks and replaces it with nitrogen.

I think I have had this arguement here with some fighter pilot before that has probably never turned a wrench in his entire life. No reason in starting it back up. Have a good one.

 

http://www.gm.com/corporate/responsi...ety/manual.jsp

GM's Position on the Use of Nitrogen Gas in Tires
General Motors does not oppose the use of purified nitrogen as an inflation gas for tires. We expect the theoretical benefits to be reduced in practical use due to the lack of an existing infrastructure to continuously facilitate inflating tires with nearly pure nitrogen. Even occasional inflation with compressed atmospheric air will negate many of the theoretical benefits. Given those theoretical benefits, practical limitations, and the robust design of GM original equipment TPC tires, the realized benefits to our customer of inflating their tires with purified nitrogen are expected to be minimal.
The Promise of Nitrogen: Under Controlled Conditions
Recently, nitrogen gas (for use in inflating tires) has become available to the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technology used in automobile racing. The following benefits under controlled conditions are attributed to nitrogen gas and its unique properties:
The Promise of Nitrogen: Real World Use

Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing. The actual obtainable benefits of nitrogen varies, based on the physical construction and the materials used in the manufacturing of the tire being inflated.
Another potential benefit of nitrogen is the reduced oxidation of tire components. Research has demonstrated that oxygen consumed in the oxidation process of the tire primarily comes from the inflation media. Therefore, it is reasonable to assume that oxidation of tire components can be reduced if the tire is inflated with pure nitrogen. However, only very small amounts of oxygen are required to begin the normal oxidation process. Even slight contamination of the tire inflation gas with compressed atmospheric air during normal inflation pressure maintenance, may negate the benefits of using nitrogen.

 

I have always wondered if more pressure variation was due to the moisture in air, and not a property of the gases. If GM said it, it must be true.

 

You think they are wrong? If so, why?

 

I got the idea to use Nitrogen when I visited my local Dealership to get some work done on the C5. While I was there I visited the showroom and checked out their Z06. I asked the salesman why the valve stems were green, that is when he told me the tires were inflated with Nitrogen. So, naturally I inquired how much it cost to do that for the C5 and since it was not expensive I added it to the tires.

Now to be totally honest, the tires I have on the C5 are not new, nor are the sensors in the tires new. So, to really test the results one should put new tires and new sensors on their C5 and start with a virgin application, IMO.