[rjardine]

In a few threads recently have noted reference to Nitrogen in the tires as opposed to air.

Then at my last visit to the Dealer noted they have a signed posted indicating a charge of almost Cdn$7 per tire to inflate them with Nitrogen.

But what are the pros and cons??

 

[hfelknor]

It can't hurt, but the benefits to a street car are minimal.

We used Nitrogen while racing. There is less water in nitrogen than air.
Water heats up unevenly and we could never be sure what pressure the tires would be at after they heated up.
Considering the fact that we can induce tightness/oversteer or Looseness/understeer in these machines with about 1/2 pound difference in tire pressure, it is important to get the tires first of all;
to raise their pressures uniformly
to raise there pressures to very close to what the team considers optimum.

There is a non corrosive element, but that has no bearing on a race wheeel. We never kept wheels long enough to worry about corrosion.

Just can't see it helping much on the street.
The street temps constantly change and the surfaces change.
There is just no "ideal" pressure.


But having said that, nitogen is cool and can't hurt.
The biggest advantage I would think is the fact that if you put 33 pounds in the tire (cold), then several weeks, and maybe months, later you will still have 33 pounds. The stuff doesn't "slow leak" like air does.


I don't use the stuff personally.

Homer

 

[rjardine]

Thnx for the explanation, Homer.

I guess I will keep my money in my wallet!!

 

[njjoe]

rjardine-

Do you really want to pay Cdn$28 to inflate your tires?

And how do you recoup that expenditure? Better mileage?...No. Longer tire life?...No. Longer wheel life?...No. Will the car handle any differently?...No. Does it sound cool to tell your friends you have nitrogen in your tires?...Yes.

-njjoe

 

[Corin]

Costco here (Seattle) will inflate your tires with nitrogen for free. If you originally bought your tires from them and filled them with air somewhere along the way, they'll even fully deflate and re-inflate with nitrogen.

Yeah, it's cool. But I certainly wouldn't bother paying for any such thing, and I won't even go out of my way to get Nitrogen. If both are available when I need it, and the cost is the same (i.e. free) then I'd go with Nitrogen simply for the "cool" factor.

 

[TN Ripper]

I have to differ with these opinions. I run nitrogen in my personal vehicle as well as my work vehicles. Better mileage...yes. Better handling...yes. Make you tires last longer.....yes. Here, it only cost $3.99 per tire and they will keep you in nitrogen for free for the life of the tires as well as keeping them rotated. I even have an air tank in the back of my Road Profiler so I can top them off if they get low. Well worth the money and I will not run on standard air mix from here on out. But that's just my opinion; and I could be wrong.

 

[njjoe]

I have to differ with these opinions. I run nitrogen in my personal vehicle as well as my work vehicles. Better mileage...yes. Better handling...yes. Make you tires last longer.....yes.

O.K. you got my attention. Please explain why you believe nitrogen-filled tires provide better mileage, handling, and tire life.

-njjoe

 

[Halo]

Yes, this I'd love to hear as well.

First thing first. "air" is already ~80% nitrogen. What you are replacing is the remaining ~20% oxygen with nitrogen. Depending on the relative humidity when you inflate your tires with "air" there might also be a very slight amount of water vapor in there (~ 1%), and trace amounts of some other gasses (C02 being one of them )


There was some BS at Costco about Nitrogen not leaking out as fast as "air." So, what they're saying is the molecular diameter of N2 is sufficiently different from O2 (it's not) that the leak around the bead and/or valve is significantly different. (Most of the leak is through the valve, the tolerances of which are not measured in Angstroms so both gasses will leak at the same rate ). Thankfully, tires themselves are not appreciably permeable to gasses.

Some other things I've seen written about:
Reducing tire heat and therefore decreasing rolling resistance. WTF? What is the basis for this? Nitrogen and Oxygen have about the same heat capacity. Water does have a higher heat capacity, but, again there is very little water in compressed air (~1%). And all of these gasses behave very close to the ideal gas law at the temps and pressures seen in a street tire.

Oxidation. This one has some truth to it. The INSIDE of the tire and wheel will be exposed to much less Oxygen if inflated with pure N2. So, if you were planning on keeping these items around for long enough to be bothered by the damage caused by this oxidation you should choose Nitrogen. Problem is, of course, you need to put the whole tire/wheel combo into a Nitrogen tank because the OUTSIDE of the thing will still be exposed to air (not to mention road debris, salt, oil, dead animals, paint and other more destructive environmental stuff.)

"But, racecars and jet planes use nitrogen so it must be better." Yes, to the extent that you can run around with a can of portable compressed N2 at very high pressure without a need for a power source or a staged compressor, yes it is better.

Does it sound cool to tell your friends you put nitrogen in your tires?

Yeah, about as cool as having red painted calipers with stock brakes, pads and all-season tires or an //M decal on a 325i.

Personally, I'd like to put Hydrogen in my tires because then when I burn rubber, I'd really BURN RUBBER :2: Or, to bottor from another BS industry, Xenon would be great because then I'd have HID tires!

 

[TN Ripper]

Alright, now keep in mind that I live in West Tennessee. It is not at all uncommon for the outside temperature here to vary 40 - 50 degrees between 2 a.m. and 2 p.m. This makes it quite a headache to maintain a constant air pressure in the tires. It is not that Nitrogen stays cooler than standard air but that due to running at proper inflation ( as compared to under-inflated ); the tires are not reshaping and therefore running at a cooler temp. Even if standard air mix is 80% Nitrogen, that leaves 20% of the gas in YOUR tires subject to more expansions and contractions. Being a more inert gas, Nitrogen really decreases the amount of side-roll that you feel when cornering.

 

[Halo]

Alright, now keep in mind that I live in West Tennessee. It is not at all uncommon for the outside temperature here to vary 40 - 50 degrees between 2 a.m. and 2 p.m. This makes it quite a headache to maintain a constant air pressure in the tires. It is not that Nitrogen stays cooler than standard air but that due to running at proper inflation ( as compared to under-inflated ); the tires are not reshaping and therefore running at a cooler temp. Even if standard air mix is 80% Nitrogen, that leaves 20% of the gas in YOUR tires subject to more expansions and contractions. Being a more inert gas, Nitrogen really decreases the amount of side-roll that you feel when cornering.

First. Nitrogen is not an inert gas. It is just less reactive. Heat nitrogen and oxygen and it will react as it does in your engine with each combustion.

Second. All gasses, be they truly inert gasses or oxygen, nitrogen, water vapor or 'air' behave the same at the temperatures you describe. Their variation from the ideal gas law is negligible below about 100C and 60 psi. The increase in pressure over a given increase in temperature will be the same whether you have pure N2 or N2/O2 mix or Argon or Helium in there. A gas inside a racecar tire may start to see temps over 100C, but that's where gasses just BEGIN to deviate from the ideal gas law. It would have to get significantly hotter before the devations begin to become measurable with consumer grade instruments (like the TPM in the MO).

I'm not saying there isn't a difference in handling between a cold tire (lower pressure) and a hot one (higher pressure). What I am saying is this difference does not vary with the type of gas you have inside the tire.

 

[TN Ripper]

I didn't bother with Nitrogen in those POS GY because I bought the car with 26K miles and it was obvious that they were going to be the first thing replaced. So of course there was a huge difference on the MO because I went to 255/60 Toyo Poxes ST's with Nitrogen. I don't think for a minute that the air is responsible for the incredible performance, it's the tires.

My work vehicle is a different story though. I drive an '01 Chevy Express 2500, 3/4 ton, extended van. Complete with LARGE front bumper containing 5 lasers and 2 accelerometers, 2 onboard computers, 17" gel monitor, printer, 2 drawer file cabinet, power-inverter, etc. It's called a Road Profiler. I check the surface smoothness of all State Highways and Bridges in all of West TN. This is the l...o....n....g van too so performance is just outstanding. ROFLMAO. Every move is ecoed by the rear-end. Without changing tires, I had them refilled with Nitrogen and the improvement was immediately clear. No more swaying in the wind, tires flatening out with each hard encounter. I can detect variances as little as .001 of an inch and obviously need to utilize an onboard Distance Measuring Instrument as well. Calibration of this particular piece of the machine is where I can see the diff. with my own eyes. Previously, if I checked the DMI calibration early and it's cool out; then work for 250 - 300 miles and check it again that afternoon, there would be a vairiance in the DMI factor used. That is no longer the case because the pressure in the tires stays at 70 p.s.i. at all times. When they are cold or too hot to touch, the pressure is 70.

 

[GripperDon]

Seems like I have been here before

First, Be sure to empty your tire of air before filling so it get 100% Filled with the new gas not just a little bit.

Second Use Argon it's improved over nitrogen.

Argon is trully inert.

Argon has much higher thermal conductivity.

Argon is a larger Molecule

I get Argon free.

 

[Enforcer]

Rent a bottle from your local welding shop?

 

[GripperDon]

I remember a kid in colledge that filled his tires with Water

Now that is one bad idea!

 

[njjoe]

Re: I remember a kid in colledge that filled his tires with Water

Now that is one bad idea!

GD-

Please tell me he was not an engineering student.

-njjoe

 

[GripperDon]

I am so old i can't remember.

It could have only been worse it it went down below freezing.

 

[hfelknor]

Damned fool should have put a few packets of jello in the tire first........

Homer

 

[Enforcer]

Well he could have filled them with equal parts of ammonia and bleach.