Nitrogen Tire Fills

[Danyol]

Interesting discussion I heard on the "Speed" channel last night. It was the substitution of pure nitrogen for air in tire fills. They said the tire would hold pressure longer and the pressure would be more stable with temperature. I did a little research

http://www.tirelast.com/id5.html

Anyone have experience of N2 in tires? I work in a lab setting and have easy access to the gas, wondering whether it would be worthwhile.

Mehmet :drive:

[Chads996]

Yep...Nitrogen is used in race tires because it does not expand in the tires like normal air does when the tires heat up. The difference between the two is rather dramatic. Upon trying this at a DE, I only had to adjust the pressures from fill up. I was running Kumhos, and I am not the fastest out there. But, I did notice that when the tires heated up...they did not get greasy at the end of the session. Whereas, before...I would have to bleed off 10-15 psi just to bring the hot tires back to my preferred pressure.

Nitrogen is much more consistant. Really not worth doing for the average DE'er. A full on Cup Car maybe...but the average DE'er won't be maintaining the speeds that racer's are running. Also...the Nitrogen is more applicable to full on race tires like Hoosiers vs. DOT legal R compounds.

Just my .02, hope it helps.

Chad

[JimB]

We use nitrogen at the track all the time. Primarily to regulate pressure as the tires heat up. Unfortunately our tires never have a chance to deteriorate from the inside. :)

The other problem with air is that, unless you are using your own compressor and take great care, you really don't know how much water you are getting in your tires. I don't use nitrogen in my street cars but if it's easy for you to get, go for it. Next best, use your own compressor and make sure you bleed the H20 out regularly. Last resort, the dreaded gas station pump.

Jim

[LVDell]

The Costco (if you can belieive it) here by my place advertises that they use Nitrogen for ALL fills now. I thought that was quite interesting. Looks like my net set will be from Costco :)

[Tool Pants]

I am not going to debate the use of nitrogen in a street car.

But I saw this Boxster at a tech session with green dust caps on the valve stems. The owner bought tires from Costco and said that they use nitrogen and put the green cap on, and it does not cost any more money.

I'm glad the SUV in front of me with tires from Costco has the green cap. :P

[JimPDX]

I am not going to debate the use of nitrogen in a street car.

But I saw this Boxster at a tech session with green dust caps on the valve stems.  The owner bought tires from Costco and said that they use nitrogen and put the green cap on, and it does not cost any more money.

I'm glad the SUV in front of me with tires from Costco has the green cap. :P

<{POST_SNAPBACK}>

Up here in Oregon Costco fills with Helium and gives us blue valve caps. The ride is quite uplifting... :jump:

[Danyol]

Guys,

Thanks for the feedback, sounds like some hype and marketing involved. Interesting discussion though.

On the subject of Helium, I see much less advantage with the gas. The molecule is so much smaller than N2 and O that it will probably diffuse right through the rubber! So tire pressure loss will likely be at a much higher rate than air.

Not sure how helium responds to heat (expansion), it is a fairly inert gas so it would most likely act similarly to N2.

Mehmet ;)

[my996]

I think he was joking. :)

[Tool Pants]

Of course he is joking. Everyone knows that hydrogen has a greater lifting capacity than helium and better suited to reduce unsprung weight. Then you put on a red cap because hydrogen burns. Like the Hindenburg....

[LVDell]

Bad....oh so bad :o

Edited February 15, 2005 by LVDell

[Danyol]

....And everybody knows red cars cost more to insure.

AND you could use the hydrogen in your on board fuel cell, picking up a couple of BHP not loading down the alternator.

[JimPDX]

....And everybody knows red cars cost more to insure.

AND you could use the hydrogen in your on board fuel cell, picking up a couple of BHP not loading down the alternator.

<{POST_SNAPBACK}>

Exactly correct!

[ADias]

Starting w/ air-filled tires, how do you evacuate the air to fill solely w/ dry nitrogen?

[ar38070]

Deflate the tire, then fill with nitrogen, deflate and fill again.

[yoshibo_n]

Hello, all,

It is quite popular to inject pure nitrogen into car tires here in Japan.

Some people say that the noise of the tire will decrease as a result because the frequency element of the noise changes.

In addition, there is a few who insist that riding comfort improves.

I'm not sure whether it is true or not, but it's not unusual to use nitrogen in the gas station in Japan.

It costs you about 10 USD to fill up 4 tyres.

[MJM]

I hope you all realize that the chemical composition of AIR is @ 78% nitrogen.

[RayGT3]

Yup, air is about 80% nitrogen but more important is the water that is also presant. The expansion coefficient of dry air and pure nitrogen is almost identical so the thing about the pressure changes being different relative to temperature holds no water. Speaking of water, that's the culprit. If you put dry air re:-70 deg f dewpoint, into a tire the performance would be identical to that of nitrogen. It's the moisture that adds all that extra expansion to the equation. Point of the message use air to fill tires that is as dry as possible. And yes, nitrogen, out of the bottle, is extremely dry.