Fill Your Tires With Nitrogen

Nitrogen varies a little less than air (e.g. temperature versus pressure), so racers prefer it.

Nitrogen holds less humidity than air, so collectors and others who are keeping cars in long term storage prefer it (reduces dry rot in tires).

Other than that, you don't get much. You won't see much difference in nitrogen versus air performance wise (just a slight bit at the extremes).

 

most go kart drivers use nitrogen down here in there tires

 

And if you believe the advertising, then 99% of all men need "erectile disfunction" pills, too.

---
And Enzo said: Let there be Search Engine And Behold ...

 

I put hydrogen in my tires to make the car lighter.

Ken

 

A lot of tire stores here in the Atlanta area always fill your tires with nitrogen when you have tire work or replacement done....

 

I'd wager they claim the efficiency improvement because N2 doesn't leak out as readily as air, so you won't be one of the (insert really high number here)percent of drivers with underinflated tires.
And its perfectly safe to top off the tire with air if needed, although... you shouldn't need to! "Nitro" is inert by itself, it gets a reputation as being dangerous when combined with "Oxide" or "Glycerine" or "Tri-Toluene(TNT)"

 

I have heard that tire placement/repair center charge $ for nitrogen.

 

I have heard, that using Nitrogen helps to slow the aging of the rubber. It is proported that the O2, in the air, working it's way through the rubber, ages the rubber moreso than being exposed to the atmosphere.

Personally, I use Nitrous Oxide, it makes my tires giggle...

 

But will it take off with a shorter runway?

 

The claim is a safe one when you consider that the average car has underinflated tires due to neglect. Inflating them to a proper pressure with any gas would make a mileage improvement.

On average in my shop cars come in with 25% or greater underinflation. Thats on a Ferrari.

Guess how bad it would be on a Chevy or Toyota.

 

Jokes aside, nitrogen makes sense for track guys who know what they're doing. It responds less to heat cycles so taking or adding a pound of air is a meaningful adjustment.

Ken

 

But that has nothing to do with nitrogen. All you are saying is that proper inflation improves mileage. But proper inflation with plain old air is just as good.

Claiming that nitrogen improves fuel economy is a lie. Claiming that nitrogen is less apt to leak out and cause underinflation is a lie. Claiming that nitrogen will age your tires less is as bad as a lie, because I dare anyone here to give me ONE example of a tire that aged to failure from the INSIDE. The outside is exposed to air, and sun, and that's where aging occurs.

Racers run nitrogen because it is free of water. Race tires get hot enough to vaporise any entrapped moisture, which causes a small pressure increase. Race tires are sensitive enough to pressure that it is worth eliminating that variable. Street tires are not. This whole nitrogen craze is a bunch of hype designed to part you from your money. Air is 78% nitrogen, DUH.

 

My last Chevy, a Corvette, had a real-time tire-pressure system (as well as a cup-holder and cruise control!) so I knew the tire pressure. I'd suspect that newer Toyota's probably have this feature by now, too.

I had to add it to my Ferrari 348, though.

Has Ferrari added such a system to their newer models? Surely. Ditto for cruise control.

Other new technology that needs to make its way into newer Ferraris would be heads-up-displays and carbon fiber wheels (already on Cadillacs, of all beasts).

I want Ferrari leading the pack again.

 

Nitrogen has a lower coefficient of expansion than air and the tires would be less prone to aging by oxidization, but this isn't a perfect seal.

In advanced coldwater scuba diving, we us Argon to fill our dry suits for similar reasons; mostly thermal

 

No it doesn't.

 

The tire rating on the side of my car says 33psi cold. Shouldn't they give you a psi hot? It changes so much depending on driving distance and outside temp. I'd rather know what the proper psi should be running so I get the proper tread wear. So if it goes to, say, 37 psi I know it's not over inflated.....

 

"How hot?"
Are they going to say measure the tread temp every 2 miles until you get to 125 degF at the center of the tread, then set the pressure?
Sure, the vehicle dynamics engineers that developed the car had the tires hot while they were doing handling/NVH tradeoffs, but then they waited for them to cool off and recorded the pressure. Now, when you're driving around town or on a back road you'll have the same pressure the NVH was evaluated at, and when you're running harder and getting the tires hot, you'll have the same pressure they were running on the test track, too. (Of course this is only valid on nice days, when it's cold & rainy out or blazingly hot out you'll be low or high.)

 

I was thinking every four miles..........lol

I have TPMS in my car and keep the monitor on all the time. It would be nice to know the running psi recommendation so that you could adjust the cold psi accordingly at diff. times of the year.

 

Well, I can tell you that NVH and handling people don't work when it's "too cold" out. That means something like below 40 or somesuch. They're a fair weather breed. Plus they say the tires and bushings get too hard and inconsistent with their sweet spot tuning in the 70s-80s. Set your pressures in the garage.

 

This is all a bunch of hooey.

Any two gasses at the same pressure/volume/temperature will change pressure as a function of temperature exactly the same, as described by the ideal gas law PV=nRT. Nitrogen does not change pressure in your tire less than air as a function of temperature.

Furthermore, even if this were not true, air is 79% nitrogen. The difference between the two in terms of temperature would be minimal. The only other major component of air is oxygen.

The only VALID advantage I have ever heard for putting nitrogen in tires is not for the benefits of nitrogen but for the benefits of the LACK of oxygen. Oxygen oxidizes the rubber and will (if you wait long enough) dry rot the tires more than a lack of oxygen. But most people wear out the treads long before that would happen.

Using nitrogen from a high pressure cylinder means that you will have no moisture in the fill, which is advantageous as well. But you can fill with dry air and get the same effect.

Birdman

 

Who goes to a tire store that uses dry air to fill your tires?
Not me. It's the water vapor (who knows how much in any given fill) in the air used to fill your tires that prevents it from acting strictly as an ideal gas.

And can someone explain to me why O2 (the biggest difference between N2 and air) DOESN'T leak out more than N2 will? A quick examination of some online references' volume data makes it look like O2 is a smaller molecule. So please explain why O2 and N2 will permeate a tire at the same rate.

Basically, the info presented by the proponents of N2 fill seems to be factual to me; the benefits may be debateable for a street car, but if it prevents people from losing their air pressure and running around on flat tires that makes it a no-brainer improvement in real world real drivers fuel economy and safety.

I dont' know how the tire stores are ensuring that they purge the air from your tire before filling with N2; that's up to the buyer to decide the efficacy of.

 

that's what i was thinking... it's not like tyres are flat-packed like a franger, they already have 50-80% of the total amount of 'air' in them before you stick a needle in it.

 

That's a big IF.

In my expeience, a street tire will hold air for months without losing significant pressure. If you have to add air more often than that, the permeability rate of O2 vs N2 is not the problem. People run around on underinflated tired because they never check them. Any small difference that pure nitrogen would make vs 78% nitrogen is absurdly insignificant.

 

The compressor condenses most of the air out during compression. It collects in the bottom of the compressor tank and that's the reason why compressors have drain plugs at the bottom of the tank and you are supposed to purge them every couple days of use. Then you can use a water seperator for the minute amount of moisture still in the air. It's pretty easy and cheap. I'm not sure if any of the tire places use it, but I do in my home shop. A water separator is like $100.

You are absolutely right.

Oxygen (atomic number 8) is a slightly *larger* molecule than nitrogen (atomic #7) so in fact, oxygen in theory should seep through rubber SLOWER than nitrogen.

Birdman