Nitrogen. In your tires.... - GreenHybrid

team_venture · #1 (**permalink**) 10-11-2005, 09:31 PM

NBC 10 in Philly just ran a piece on replacing old-fashioned air in your tires with yes, nitrogen! Less leaking, less pressure fluctuation, better gas mileage, safer handling, probably makes them smell nicer too.

Costco, (hey, weren't they just mentioned in another thread for buying cars?) and a few service stations will do the switch. No mention of price, and of course you still have to maintain proper pressure.

Good enough for NASCAR and NASA, how about you?? Story is located here.

Fred

bar10dah · #2 (**permalink**) 10-11-2005, 09:45 PM

I believe Sam's Club does that service, also. I'm going to have to take a ride down to check it out.

hawkGT647 · #3 (**permalink**) 10-12-2005, 05:10 AM

Quote:

Originally Posted by team_venture

Less leaking, less pressure fluctuation, better gas mileage, safer handling, probably makes them smell nicer too.

I don't think any gains in fuel mileage by switching from air to nitrogen could be measured.

Air is already 75% nitrogen, and I don't see any way it could increase fuel mileage. (not for tires that are kept properly inflated).

Maybe decrease the moisture content, and decrease the breakdown of the rubber compounds from oxidizing.
It is more stable at holding pressure through a temperature change, this is the main reason racers use nitrogen. (The Air Force F-4 Phantom jet I worked on used nitrogen in the struts and tires)

That's all the benefits I can see.

Regards,

Civic Duty · #4 (**permalink**) 10-12-2005, 05:45 AM

Quote:

"Nitrogen is four times heavier than oxygen, so those molecules are bigger and won't be able to escape through small leaks in your tires," said Catherine Rossi, of AAA MidAtlantic.

No - Nitrogen's atomic mass is 14; oxygen's is 16. They both exist as a diatomic molecule in gaseous form, so N = 28 and O = 32. It is actually true that because nitrogen has fewer protons in its nucleus to pull on its electron cloud, nitrogen has a larger size (0.92 angstroms compared to oxygen's 0.65).

Sorry to be picky - I just hate when people, ostensibly in a legitimate position to provide facts, dispense pseudoscience. Even if her final conclusion was more or less correct: nitrogen molecules are bigger.

And hawkGT makes a good point. How much of a difference can it possibly make to replace the 21% of air that is oxygen with nitrogen under normal (i.e. non-thermal) driving conditions? Has anyone actually done this to their tires in this forum?

Schwa · #5 (**permalink**) 10-12-2005, 06:22 AM

I could do it for free since I bought my tires at Costco.

What I read is that oxygen will actually leak through the rubber itself (not small holes) so pure nitrogen in a non-leaking tire will not slowly seep through the tire wall as oxygen would in regular air.

dfgf · #6 (**permalink**) 10-12-2005, 07:49 AM

My tires came with "Nitrogen Inflation" when I replaced them on my Element. Impossible to measure whether or not the nitrogen actually gave me any mileage benefits, as my mileage went down due to the new grippy tires.

The place that I went to was Tire Discounters. They're big in Cincinnati - not sure where else they're located. They list a long list of possible benefits of nitrogen, but increased fuel economy isn't one of them.

Clubford00 · #7 (**permalink**) 10-12-2005, 08:00 AM

The only benefiet is nitro is less likely to fluctuate, problem is the tires themselves leak. And one more thing...PSI is PSI no matter what is in their i mean really...which weighs more,? a pound of lead or a pound of feathers.? lol...PS lets all put Helium in our tires for less friction and better MPG hehe

livvie · #8 (**permalink**) 10-12-2005, 09:30 AM

moisture in the air especially at a tire pumping station is the big culprit in tire pressure fluctuation. remove the all the moisture in the air and you will get good results. using "pure" nitrogen, solves this issue without a fancy water separation filter.

lakedude · #9 (**permalink**) 10-12-2005, 03:35 PM

Hawk is right about air being mostly nitogen anyway.

Livvie has a good point about moisture. If filling with nitrogen has any real advantage it must be that it is water free.

ender21 · #10 (**permalink**) 10-12-2005, 03:40 PM

Quote:

Originally Posted by Civic Duty

No - Nitrogen's atomic mass is 14; oxygen's is 16. They both exist as a diatomic molecule in gaseous form, so N = 28 and O = 32. It is actually true that because nitrogen has fewer protons in its nucleus to pull on its electron cloud, nitrogen has a larger size (0.92 angstroms compared to oxygen's 0.65).

Sorry to be picky - I just hate when people, ostensibly in a legitimate position to provide facts, dispense pseudoscience. Even if her final conclusion was more or less correct: nitrogen molecules are bigger.

So what you're saying is that Nitrogen escapes slower because it's *bigger,* not because it's *heavier.*

And wouldn't it be atomic *weight*, not atomic *mass*? N's atomic weight is approx. 14, and O's is approx. 16 which makes that whole "four times heavier" quote a definite head-scratcher.