Are there any problems with the tire pressure sensors when inflating the F1 supercar EMT's with nitrogen. With air , my tire pressure ranges from 29 when cold, to 39 when hot. And this is just on normal around town driving.

 

I believe the point of nitrogen is so that you won't have those variances. To be honest, I'm not sure that it changes much at all. As far as the effect on your sensors, the air you're using now is 80% nitrogen, so I wouldn't expect any problem.

 

I've had nitrogen in my '05 since November and I think it's just great! There is'nt the big sudden temp swings and the sensors work just fine!!

 

Here is a thread that beat that subject to death---> http://forums.corvetteforum.com/show....php?t=1276112

General consensus is that the nitrogen filled tires will react almost exactly the same as air filled tires being that air is almost 80% nitrogen. If you have very wet compressed air, the drier nitrogen might make a small difference.

 

Please measure your tire pressure before driving and then immediately after driving at least 40-50 miles and let us know if what you say is true. Filled with "air" the tire pressure would vary from 30 to 34-35 on a normal day (60 - 70 degree ambient temp.). We want to know if yours goes from 30 to 31-32 as all the nitrogen suppliers would have us believe. Thanks for being the guinea pig...

 

so if your temps are moving that much something is wrong.

 

May I suggest you carry a fire extinguisher?

 

From what I have noticed, it's a more gradual change!! I'm not saying it doesn't change! It may be because it has been a tad cold here in
N.Va, and it takes a little longer for any tire to warm up. But it does seem to be different than with just air.

 

High School physics class on the gas laws: PV/T = P1V1/T1. There is no fudge factor for nitrogen versus air! Pressure is a function of temperature for both and flexing of the sidewalls plus ambient temperature changes dictate pressure not molecular composition.

 

any gas will increase pressure as heat rises. "nitrogen" in tires is just another gimmick to get your money, what possible benefit (measurable and meaningful) could you derive from it.

 

Any air that is compressed from the atmosphere is going to have a certain amount of water included, filling the tires with 100% pure nitrogen eliminate the water, sensors will still read the associated pressures depending on the temp.

 

What you need to do here is to lookup the partial pressure of water vapor as the temperature of the tire gets close to 200dF. You will find that the PP of WV increases dramatically as one approaches the boiling point of water. The difference is that at low-ish tire temperatures (say below 150dF) the PP of WV is low enough to be ignorable, and not so ignorable at higher temperatures.

BUT (the big but) this is only a real concern with tires operated at race-track useage levels, at adult street levels of use there is not really any useful difference. However, at the track, tires filled with nitrogen can start a session at 32 PSI and end the session at 40 PSI while a tire filled with semi-wet air has to start closer to 29 PSI to end up at 40 PSI.

 

TSB 05-03-10-020
Info - Use of Nitrogen Gas in Tires - (Dec 22, 2005)

All 2006 and Prior GM Passenger Cars and Light/Medium Duty Trucks

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:

• A reduction in the expected loss of Tire Pressure over time.

• A reduction in the variance of Tire Pressures with temperature changes due to reduction of water vapor concentration.

• A reduction of long term rubber degradation due to a decrease in oxygen concentrations.
Important: These are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions.



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.


GM Tire Quality, Technology and Focus of Importance
Since 1972, General Motors has designed tires under the TPC (Tire Performance Criteria) specification system, which includes specific requirements that ensure robust tire performance under normal usage. General Motors works with tire suppliers to design and manufacture original equipment tires for GM vehicles. The GM TPC addresses required performance with respect to both inflation pressure retention, and endurance properties for original equipment tires. The inflation pressure retention requirements address availability of oxygen and oxidation concerns, while endurance requirements ensure the mechanical structure of the tire has sufficient strength. This combination has provided our customers with tires that maintain their structural integrity throughout their useful treadlife under normal operating conditions.

Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehicle manufacturer in many areas, including comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load carrying capability of a tire is related to inflation pressure, proper inflation pressure maintenance is necessary for the tire to support the load imposed by the vehicle without excessive structural degradation.

Important: Regardless of the inflation media for tires (atmospheric air or nitrogen) inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance.

 

Thanks MyRedC6, excellent summary.

 

That one is always amusing. Air is 80% N2 and only 20% O2. If the molecular sieve feature were significant, we would end up with only nitrogen in our tires after we topped the pressure off several times because all the oxygen would have leaked out and we would have nearly pure N2 remaining.

So, if it really is a problem it's self correcting, if it isn't a real problem, the claim is pointless.

People filling their tires from a well maintained air compressor in a dry climate will get basically no benefit from N2. People using poorly maintained air compressors in armpit like climates might. It's the water that makes a difference if anything.