nitrogen?

[dogstar]

i was reading some ads and i came upon this little bit of scrawl.

"Have you checked out Nitrogen yet?.... If not, now is a great time to consider filling your tires with Nitrogen, as your summer vacation approaches.

Consider some of the benefits...
• Increased Tire Life
• Better Performing and Safer Ride
• No Air Pressure Leakage
• Better Gas Mileage
• Cooler Running Tires

Right Now... We have an introductory special.
Fill all 4 tires for only $19.95
A Saving Of $5.00!"

now if this is true, it could be a real good deal, but cmon... nothing is perfect, what are the downsides?
how can nitrogen increase your tire life and make your tires perform better?

[Dangerous Ken]

Sounds like the points are just as valid for simply the Proper Inflation of the tires, with Air, not Nitrogen.

But this bullet point is humorous - '*No Air Pressure Leakage'

If the tire is filled with Nitrogen... (thus no Air :rolleyes: )

I used to use nitrogen in cold taps for beer instead of C02 because it is 'insoluable' in beer. i.e. some kegs get too 'foamy' with CO2 pressure.
Point is if Air doesn't leak out of the tire, Nitrogen wouldn't either.

Ken

[BillyM]

Atmospheric air is mainly nitrogen.

...up-side to pure nitrogen is that it has lesser expansion properties than air, if I remember correctly. ..nice for racing because your cold and hot pressures differ less.

--BillyM

[Supra GTR]

Pure nitrogen.. if done properly (evacuate air out of tires and then reinflate with nitrogen) does not have oxygen.. thereby no oxidation of tires nor wheels.

We did run nitrogen in race tires... especially Hoosiers because they vary noticeably in performance with the slightest change in pressure and temperature. Nitrogen is less susceptible to variances than air.

If you can get nitrogen for free.. do it. If you have to pay.. stuff it.

Downsides:
- Trying to find a shop that will properly evacuate your tire and refill it with pure nitrogen.
- Price
- if improperly inflated.. you get the same damn results as an improperly inflated tire with plain air.
- if you happen to run low on nitrogen due to a slow leak (valve core, valve seal, foreign objects in tire), you'll have to go back and pay money to refill
- can't just refill at any gas station.. defeats the purpose of having nitrogen in the tire.. so much for long trips


Upsides:
- less expansion and contraction due to temperature variances, thereby giving you consistent performance
- pure nitrogen has less moisture than air
- oxidation of rubber on the inside is negated (but you still have to deal with UV and oxidation of tires from the outside.. thereby giving you different contraction/expansion rates with the outer vs. inner wall.. so the wear is still the same on the outside).

Is it worth it? You will have to justify that on your own. Personally, until every gas station in North America has it, I'll just sit back and fill my tires with good old fashion polluted, allergen filled air. .. unless I'm going racing on a consistent basis.

Regards,
James R

[dogstar]

some good points... and basically what i thought, its mostly hype. :)

[StanS]

Prolly the water vapor in air's the culprit. Some may condense at times or evaporate when internal tire air gets hot giving different amounts of gas in tires at different times (hot/cold) so pressure variation in tire would be greater with temp. Best solution is to move to the desert or dry the air that goes into your tires.

[Funkycheeze]

we use nitrogen on the racing car tires, we carry a little bottle around to top them up if they get low, and evacuate them with a vacuum system before inflating the first time

basically there are five main benifits

-no oxygen, so the wheels and tires so not oxidize on the inside
-because there is only nitrogen in the tires, and it is a relatively 'big' molecule compared to other gases found in normal 'air' it does not leak nearly as much
-the TV properties of nitrogen are alot better than that of air, as in it expands less with increased temperature
-the heat capacity of pure nitrogen is greater than that for air, and it transfers heat faster across the tire and into the wheel
-no water vapour in there either (can have big effect on oxidation and temperature expansion)

again, it needs to be done 'right' - one of the tire shops in town does it right, but it costs like 10 bucks a wheel, plus then you need to pay to get it refilled if you lose pressure, and also i like to increase the tire pressure in a street car when it gets used on the track

bottom line is that its the way to go on a racing car, where the small benifits will pay off, but its not very practical from a consumer/street driving standpoint

[dogstar]

hmmm, i should get my brother to sneak me a bottle of nitrogen from the welding gas supply company he works for. ;)