Absolutely agree with Mike- Nitrogen is a hype.

1. Bottled, pure technical nitrogen- like they use on aircraft, race cars, is PERHAPS marginally better in that it is moisture free, no doubt. It will also not release air in the event of a fire and rupture. (particularly an issue in aircraft at altitude, who wants oxygen if there is a wheel well fire.)

2. Tire store Nitrogen concentrators can only go 94%. And it is as 'wet' as their compressed air from their compressor. total Scam. All the benefits they extrapolate from meager pseudo science fall apart when the true is 6% of the fill is air, and it has the same moisture as their air...

3. Teams use nitrogen since it is easy to buy a bottle, safe if the bottle leaks and really just a 'known quantity'. I would guess just 'pure bottled air, certified moisture free' would be acceptable. (But this isn't sold to my knowledge, since air is many different gasses..)

What I have found incredible interesting is the pseudo-science and half truths around the nitrogen buzz being promulgated by tire retailers, tire retailer organizations and companies that sell nitrogen concentrators.... marketing literature abounds that tells tire retailer they can make $5-10 more per tire with this scam

When I see green valve stem caps I think 'sucker'...

A

 

I stand by my post.
There is simply not enough water vapor in compressed air to make any significant difference in tire pressures when heated.
I've said a dozen times, if you want to use Nitrogen, go ahead. I just think it is a waste of money and incredibly over-hyped.

 

nielsll-

Wait, so is your position that Nitrogen isn't the benefit- that all that 'matters' is to maintain a 100% moisture free fill?

 

From a performance standpoint, the type of gas is unimportant. It is the water vapor in air that creates the unpredictable pressure increase relative to the temperature as the tires reach operation temperature. Nitrogen is relatively cheap and available. It does add safety as Mike mentioned in applications where fire is of concern. Also nitrogen has about 1/2 the permeability when compared to air. So for people who rarely check and adjust their tire pressures, they have a longer periods of safety.

To obtain the real benefit for performance applications, you must start with a dried tire, mount with a non-aqueous agent, totally purge all air from the mounted tire (several times), inflate only with a pure gas. Watch a NASCAR or F1 team to see how they manage tire pressures to 0.1 PSI. The care they take may be unnecessary for most drivers can't discern such small changes. but a dry fill will exhibit approximately a 1/2 psi less difference as compared to a tire filled with compressed air as it goes from ambient to operating temperatures.

 

Can we agree that the nitrogen sold in tire stores is NOT the nitrogen you are talking about (in terms of dryness)?

Interesting... so many places I read folks proclaiming "Nitrogen in my tires and I get NO variation with temperature on the track. Kudos to you for a bit more truth: 1/2psu variance in DELTA. So you can get 87si change with regular tank air, but 6.5psi with a meticulous dry fill.... so half a psi.... hmmm. Good to quantify.


Finally, since air is 78% nitrogen... I find it amazing all the benefits of using 95% nitrogen from tire stores: Safer, better gas mileage, saving money, tires last longer, bigger tats, longer, etc,etc Amazing what 17% more nitrogen gets you...They've taken a few marginal arguments, and constructed an industry around them.

 

I use nitrogen in my car and it it works fine, I usually have to top off the tires once every four to five months. so the pressure does stay consistent.

 

Well, it is a wonderful debate.

All in, I still stand by my position that there simply isn't enough water vapor in compressed air to make any measurable difference in tire pressure or vehicle performance. Even if there were a .5 psi difference, which I sincerely doubt, most of us would have a hard time even measuring it.

When you add in the relative high cost of the nitrogen fill, it simply makes the practice of using nitrogen in tires almost ridiculous. I contend the money would be better spent on some quality car wax, dinner with your significant other, or a donation to your favorite charity.

This "Nitrogen in tires" question comes up frequently, due to the amazing marketing engine that drives the nitrogen business. Hopefully our collective and spirited discourse has served its purpose; to carefully question claims that may not be credible.

 

The best uses for nitrogen are in accumulators and shock absorbers. The reason is not the expansion rate, but the fact that under extreme use and heat, nitrogen being an inert gas will not promote combustion.