OT: Anyone using nitrogen in their tires?

[Me No Nemo]

I've heard, and been reading, about filling auto tires with Nitrogen for better gas mileage. Anyone tried it yet? With both Tom and I driving an hour each way every day I'm looking for ways to cut down on the gas, especially as they're predicting $4.00 per gallon soon!

 

[chrisstie]

Granted this is on a website that provides Nitrogen but the have a florida news cast on it that talks about it

http://www.purigen98.com/

Apparently it takes longer for nitrogen to leak out of your tires thus keeping them properly inflated longer... and properly inflated tires means better gas milage versus underfilled tires.

At least, thats what I've found out. It says Nascar and airplanes use nitrogen in their tires and it just hasn't been available to the public until now?

Sounds neat actually

 

[cstires]

I personally haven't tried it, however I have a good friend that owns his own repair shop and we've discussed it before. It has really good benefits compared to air, however the problem I continue to worry about is that our tires are not manufactured with nitrogen in mind, instead they are manufactured for air, which heats up, expands, increases pressure, etc...

They have the ability to do either at their shop, however they don't fill it with nitrogen unless requested by the customer. I think I'll give it a little more time to see how things go, but it would be nice to put something in the tire that would keep a constant pressure, and not eat away at the tires, rims, etc...; wouldn't it?

 

[chrisstie]

I'm wondering how useful this could be for the average person who drives maybe 10 hours a week tops or so. Lets take that versus a trucker who drives nearly 24\7 except when he's sleeping. I can see the trucker getting more benefit.

Also isn't our air 4\5 N2? What does taking away 1\5 O2 do to really improve it that much?

I am kind of on the fence on this one here

 

[skinnyjoe1976]

another concern is the cost. the dealership i worked at found that it wasn't cost effective and not enough customer interest to invest in the machine. and lets say you get it filled with nitrogen and then take it to another shop and they don't read the label on the valve stem and they put normal air then you would have to take it back to the supplying dealer or shop to evac the normal and recharge with the nitrogen. pretty much a pain. best thing is to check you air pressure weekly with a high quailty air guage and fill according to vehicle specs on the label usually on the driver's door cold. remember tire decrease pressure cold and increase pressure hot. p.s. don't over inflate the tires due to heat expansion and exceding tire specs.

 

[cowboyswife]

This thread reminds me that I need to add air to my truck tires. Thanks guys!

 

[Me No Nemo]

Well, apparently when you get them filled with Nitrogen, they put a special valve on that's blue, so I guess regular air doesn't fill on that. There's apparently a place in Oviedo that does it...I keep my 4-runner serviced and the air in the tires are checked every 3,000 miles, so I know my tires are inflated right. Any other thoughts on how to save gas?

 

[TheGrog]

Being an ex-mechanic and having a number of friends who are mechanics / gear-heads and even one who works as an engineer at Bridgestone. I have discussed this at length with them on a number of occasions.

So, here is Science 101 meets Auto Zone

Yes the air we breathe is around 80% nitrogen, it is the oxygen and CO2 that damages the rubber in the tires. By removing them from the inside, there is less oxygenation done. However, there is limited oxygen inside of the tire and once it is used up, the oxygenation process stops until more is added. The arguement thast the nitrogen slows the deterioration of tires is essentially false. Yes, there is no deterioration inside of the tire, but if you look at some tires worn past the steel belts on the outside, the inside still looks like new!! This is why they strip and retread truck tires.

As far as the leaking goes, all tires will slowly leak air whether it be pure nitrogen or regular air. The tire is sealed by pressure from inside the tire against the metal rim. There you have two totally different substances in contact. They contract and expand at different rates with heat and cold, thus creating micro gaps and letting air out. Nitrogen (N2) is slightly larger a molecule so less of it can get out of these micro gaps, but it does leak. With regular air, all you need is an accurate pressure gague and an air pump. With nitrogen, you have to take it in and trust them to accuratly read it and fill it. No offense to anyone working there, but I would rather trust my own eyes on this.

As far as the tire being manufactured for air and not nitrogen, it makes no difference whatsoever. The expansion and contraction rates are not that different between nitrogen and air to make any difference in the performance of the tire.

Now, the reason that Nascar and airplanes (and NASA) use nitrogen is that they don't want ANY pressurized oxygen around. Those tires can get incredibly hot and they don't want any chance of oxygen being present to allow a fire to happen. Also those NASCAR pit crews will do anything to gain even the slightest edge be it real or urban legend.

So the bottom line is to check your tire pressure monthly and keep it in range. There is a sticker usually on the inside of your drivers side door that has the manufacturer's recommended tire pressure for front and rear tires. Go with that rather than what is on the sidewall of the tire. Do that and your gas milage will be optimal and your tires will last longer!

I'll get off of my soapbox now

 

[TheGrog]

<a href=showthread.php?s=&postid=10071842#post10071842 target=_blank>Originally posted</a> by Me No Nemo
Any other thoughts on how to save gas?

I know of many. My 1991 Camry still gets 29 mpg on the highway! Here are a few tips:

Change your air filter every 6000 miles
Rotate your tires every 6,000 miles
Check at adjust (fill or drain) tire air pressure MONTHLY!!
Replace your oxygen sensor every 25,000 miles
Replace your fuel filter (if your car has one) every 25,000 miles
Replace your spark plugs with high quality plugs every 25,000 miles
Replace your suspension (shocks and/or struts) every 50,000 miles
Have your alignment and brakes checked and serviced if needed YEARLY

Seems like a lot of work, but if you can get another 2-3 mpg out of your car, at $3.50 per gallon that adds up quickly!!! Most people (and a lot of mechanics) forget the little things. Most of these things can be done by yourself at home for a fraction of the cost of what a shop will charge.

Hope this helps!

 

[Me No Nemo]

Thanks for the info! I'll check my service records and see what hasn't been done against your list. Marcye

 

[mflamb]

As a mechanic for the past 31 years, and one that keeps up with all the latest technology and ideas, I have studied the nitrogen idea for several years and have spoken with many engineers from our tire suppliers from Goodyear, Firestone, Pirelli, Michelin, Continental, and others. The concensus is exactly what TheGrog said. Since our air is already 80% nitrogen, the difference is so minimal, that for the average driver, there will be no measureable difference. Good normal maintenance is the key to fuel mileage.

 

[magnoliarichj]

nitrogen does not expand or collapse at diffrent temps. thats the benefit. so if you drive 100 miles in the desert with a tire pressure of 40psi then at the end of that 100 miles the tire pressure is still 40psi. more consistet feel from the car thats why races use it. not drag but lemanns type.

 

[magnoliarichj]

test it. i have.

 

[gpep419]

ive realy ben thinking about this sence all 3 of my cars are bad on gas and have alumium rims. so between the gas and the tread on the tires wearing out i think in the near fucture im going to try it

 

[TheGrog]

<a href=showthread.php?s=&postid=10074168#post10074168 target=_blank>Originally posted</a> by magnoliarichj
nitrogen does not expand or collapse at diffrent temps.

I am sorry, but this could not be more wrong. The universal gas law says different. ALL gasses will expand with increasing temps and pressure & volume are directly related to temp.
PV = NrT (Pressure * volume = # of molecules * universal gas constant * Temperature).

Since the tire volume stays relatively constant as does the number of molecules, the pressure and temp are DIRECTLY related. temp goes up, so does pressure and so forth.

As far as testing it, the only way to get an accurate test read is to measure not only the pressure, but the temp of the gas inside of the tire. Just because the tire rubber is hot does not necessarly mean the gas inside is the same temp. Tire rubber is very insulating and both aluminum (rims) and gasses are very good at absorbing and dissipating heat so any heat to the gas inside of the tire would be quickly transfered to the rim and dispersed whereas the rubber would hold onto the heat. Simple thermodynamics. I've seen this and done this in the lab durring undergrad advanced physics classes.

I'm not trying to flame you, just putting out what I know.

 

[sytanek]

this was kind of funny...I read this thread last night, flew to charlotte this morning and the first billboard i saw was for

http://loveyourtires.com/

Which is a site trying to get people to use nitrogen...lol

ok well it was funny to me, but I guess 4 hours of sleep before having to fly out of town will do that to you.

 

[jay24k]

I'm curious why you would replace some of those items so often? Struts every 50K miles? Kind of a waste if you ask me especially if your current ones do fine. The mechanics at the City all mention how struts "should" last you easily over 100K miles. On my prelude, manufacturer recommends spark plugs at 90K miles. Granted they charge 50 dollars a plug for some reason. For that I'll buy em online.

As far as the nitrogen, I would think it would cost more in the long run. Plus the headache of having to fill your tire so you would have to find a nitrogen place. And most tire places I know for some reason, cannot figure out how to fill your tires up to specs. I get my tires back at 30psi and I have to put in 44 psi

 

[mflamb]

<a href=showthread.php?s=&postid=10074168#post10074168 target=_blank>Originally posted</a> by magnoliarichj
nitrogen does not expand or collapse at diffrent temps. thats the benefit. so if you drive 100 miles in the desert with a tire pressure of 40psi then at the end of that 100 miles the tire pressure is still 40psi. more consistet feel from the car thats why races use it. not drag but lemanns type.

Once again I bow to TheGrog, who is correct. PV=nRT applies to all elements. Now some do expand with heat more than others, and the reason "air" has a higher expansion rate in some tires is the moisture content of the air. In my shop, we have one of the highest quality air dryers on our compressed air system, so the moisture content is at or near zero. Nitrogen is dried as it is produced and is not near as hydroscopic as the oxygen in "air".
Find a quality shop to do your maintenance and problem solved. ALL oil changes done in my shop get air pressure set to manufacturers specifications as stated on the door or door jamb of the car/truck, unless a different psi is requested by the customer and then we set it to that as long as it does not exceed the max psi recommended by the tire manufacturer.

 

[jay24k]

Do you verify that the tire is different? For example, my car comes with 14's stock. However, I have 17's. The recommended psi I think is 34 however my tires are 44. Maybe that is why I can't find any shop that files my tires up to the tire recommendations.

 

[sytanek]

lol, is it printed on the tire? From my past experience most guys don't know what originially came on the cars, they go by what is on the car that moment.