nitrogen in passenger car tires?

***********************quote************** Pressure is vital because a properly inflated tire is a safer, more efficient tire. The National Highway Traffic Safety Administration says

most drivers can improve gas mileage by nearly 3 percent by keeping their vehicle tires within the recommended pressure range. The government also estimates the nation loses more than 2 million gallons of gas every day due to underinflated tires

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I suspect that rather than saving energy consumption on a national level, the use of nitrogen in tires would do the opposit. The energy used to accumulate, purify, and compres the nitrogen would exceed the energy wasted by low inflated tires. Moisture is the real culprit that causes unstable tire pressures as the temperatures change. A simple air dryer filter used on the compressed air would solve most of the problem.

Kevin

I don't know about decomposition, but moisture in air greatly affects its pressure change with temperature. That is why racing tires are frequently filled with nitrogen or special "dried" air. With an unknown moisture content one has no good idea of what the pressure will get to when the tires heat up on track.

On passenger cars, the humid air does create a greater temperature change than predicted by simple gas equations. However, the fact that you need to check pressure more often when temps change doesn't seem worth the expense of a dried gas to me.

Bogus is argument that nitrogen molecules are larger and therefore leak out more slowly than air. Air is 80 percent nitrogen already, and oxygen, the other major constituent, is very similar in size and weight to nitrogen.

This is foolish. You should be using helium in your tires. Because helium is ligher than air, it will actually reduce the effective weight of your car without changing the mass. Of course, you have to top the tires off every hour because the gas diffuses through the rubber, but that's just the price you pay to be part of the leading edge of technology.

--scott

And you will have to adjust the mix of helium as you change altitude. That car could just go floating off into the sunset!!!

Another thing to note, is that if the oxygen leaks out of the tire faster than the nitrogen, the tire will act like a crude molecular sieve of sorts. You keep filling the tire with air at some 78% nitrogen, the

21% oxygen leaks out leaving the nitrogen, you top up with air, etc. and you end up with like 99% nitrogen after a while.

Pete C.

Heh heh...

Circa 1970, we did just that... filled the tires with gas(oline) vapor. WE used those "Engineair" kits, which screwed into a spark plug hole, and pumped the tire full of carbureted mix as the engine idled.

I believe they have been outlawed in most states, now. Then again, maybe not:

Helium filled boots are your best bet. You'll save on fuel, and on speeding tickets!

Don't be a peon; use neon or Freon, which we all agree on!

What does it sulfur? Ammonia novice at this, so I can only take a gas at it.

But you'll lose traction. So a RWD car should have helium in the front and co2 or xenon or radon in the back then? ;)

If there are any of you that are as old as I am, let's test your memory.

Which service station chain had a marketing ploy in which they claimed to use Pink Air to fill your tires?

I think you should take these bad puns and barium.

--scott

You argon a get yours for punning. Perhaps the pun police will conduct a radon your premises. You'll be booed if you're xenon the streets.

In particular, they speak of ozone damage. Ozone is a triatomic form of oxygen, and is considerably more reactive than diatomic oxygen. It usually forms when oxygen is subjected to electrical discharge, such as near high voltage transformers, lightning, electrostatic sources, etc. There are also chemical sources.

I did not mean to directly relate the oxygen to the damage. It is indirectly related through the formation of ozone and the further reaction of the ozone.

Nitrogen also has a lower rate of expansion than oxygen. the benefit is that when you inflate your tires to 35 p.s.i to go racing, the pressure wont change as much when the tires eat up. although since the air we normally put in is 79% Nirtogen anyway, it dosent really matter that much for u and me.

BTW, ive heard of some racing teams filling their tires w/ helium to lighten them by 6-8 ounces. i guess every little bit helps eh...

Okay, but you still don't have nearly as much ozone generated inside a tire as you do outside, where there are sunlight, ultraviolet light and electrical arc discharges. So even if there's significant ozone generation inside a tire, the outside still stands to take the most damage, the inside comparatively little.

just curious - why so much activity on the subject, does anyone see an advantage to using it in personal cars, and if so - what is it?

mho v=83e

No way! Cars are too heavy to float. They'll just flip over, wheels pointing up.

UV radiation also creates ozone from O2. But how much UV radiation or lightning goes on inside a tire?