What's Your Thought's on Nitrogen Tires

We touched on this subject quite some time ago, Now with the gas prices skyrocketing and no end in site, what do you guys think about Nitrogen Filled Tires instead of Air. They claim it will give you better mileage?

http://news.yahoo.com/s/ap/20060731/ap_on_bi_ge/nitrogen_tires_1

1 mile per gallon doesn't work for me.

I've been running nitrogen in my vehicles for the last year and a half. The thing I noticed the most was that the pressure never needs adjustment. I put in XXpsi and it stays no matter what - even the season changes. As for the mileage, The jist I got from reading the propaganda is that due to the unchanging psi your tires will run better and cooler than using air. I like it and it doesn't cost me any extra cause I bought the tires from a store that only uses nitro.

Normal air is 79% nitrogen.

http://upload.wikimedia.org/wikipedia/commons/6/66/Air_composition_pie_chart.JPG

sounds like another turbonator thing to me. To good to be true.

Hello,
I run to with nitrogen for a long time.
No improvement in milage but a very stable pressure in the tires generaly only one adjustement per year is necessary.
Tires stay cooler.
As Blazer LT says 79% of nitrogen in air but the 21 other % have smaller nuclear nodes than the nitrogen and are the ones going out trough the tire.

What Serge says is correct. The molecule size of Nitrogen is larger that that of compressed air, thereby not allowing any leakage through the beads, sidewalls or valvestems. This results in your tires maintaining a more constant pressure - which could result in a minor to major mileage improvement, depending on how diligent you are in keeping your pressure up to specs.
Some places are offering Nitrogen tire pressurization at no additional cost, and I have noticed some places in MD and PA (USA) that have "filling" stations that are the same prices as an air filling pump.

So really, your tires can only change in pressure by 21% at most if filled w/ regular air.

GM's stance is below.

My thoughts - if it's free, why not. When I got my tires replaced a while back, they wanted to charge me $30 for nitrogen. No thanks. I'll check my tires once a week like I do already.


Tires/Wheels - Nitrogen Gas Usage for Filling Tires

Bulletin No.: 05-03-10-020

Date: December 22, 2005
INFORMATION
Subject:
Use of Nitrogen Gas in Tires

Models:
All 2006 and Prior GM Passenger Cars and Light/Medium Duty Trucks (including Saturn)
2003-2006 HUMMER H2
2006 HUMMER H3
2005-2006 Saab 9-7X

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.

If your spending an extra 30 bux to fill a tire just to get better gas mileage why not just buy better tires in the first place that'll give you better mileage and last longer

Exactly. Not to mention that the aluminum wheels on my Bravada, judging by past history, will eventually develop a slow bead leak and that $7.50 worth of 100% Nitrogen would slowly get replaced with 79% nitrogen from my air compressor....

I've heard the benefit in my area (Alaska) is the nitrogen does not have the same expansion and contraction as "compressed air" leaving you with better inflation in the winter. Slack tires due to the outside air temp of -20 deg F can really effect your gas milage. It's starting to make it's way around this area and I was thinking of getting my tires studded and mounted with Nitrogen to see the winter affects.

Hmm, aren't all gases governed by the same gas laws? Charles, boyle , ect. If the temp rises the pressure has to. Does the Nitrogen control temp better?

Here's another thought, If the pressure rises because of heat, the mileage will probably go up. Simply raisiing the tire pressure higher may give better mpg.

If I had to change tire pressure more than twice a year I would assume it had a leak and get it fixed. Just in case, I am not a big fan of this using Nitrogen.

I have had Nitrogen in my tires before and never saw an improvement worth a rats ass. I did notice how everyone else stated that the psi. stays constant though and that was also the case for me. Just my .02

how do you remove the ambient air from the tire when it is installed on the rim to begin with? otherwise, your not getting a pure fill from the start...

You would have to purge it to keep getting a purer mixture.

You would have to purge it to keep getting a purer mixture.

And how do you do that?

I never see them doing that when they are initially filling a tire with Nitrogen so I guess it is a scam then.

Fill it, let it back out and repeat. 4-5 times might get to 99%.

Anyone spending $7.50 a tire on nitrogen just paid more than the savings they are going to see over the lifetime of the tire.