Nitrogen in tires

[pokerfan]

What a freakin' scam this is. I'm seeing it more and more with gas heading to $4. Just another way to lighten your wallet up to $10 per tire.

[Wcross]

1. I used to test tires for a living, we used nitrogen for some of the testing.

From what I understand it doesn't expand/contract as mush as plain air. I don't know why it would be a great benefit other than slightly increasing your tires lifespan (maybe).

[pokerfan]

2. It's not that it doesn't expand/contract

as much as air. All gases behave the same according to the gas laws. It's that air has a moisture content that is equivalent to the atmospheric humidity at the time it was compressed. This means that it expands/contracts in a predictable fashion, which is probably why you used it for testing. But the difference is negligible for the average driver. The Nascar and Formula-1 guys notice it because they care about even fractons of a psi. But the average driver won't notice a thing except they get fancy looking green valve stem caps.

[quip]

3. Especially since regular ol' air is already composed of 78% nitrogen in the first place...

[Wcross]

9. My assumption was based on what I observed.

We would fill a tire at room temperature & then place them in heated rooms (100 degrees) for conditioning. The air filled tires would always gain 5-10 pounds of pressure where the nitrogen filled tires usually did not gain more than a pound or two. I defer to your knowledge on the subject, I just assumed it was because of the lower expansion/contraction.

Me, I am sticking with plain old air!

[pokerfan]

14. Hmmm... I'm not a tire expert

but I just don't see what special property Nitrogen possesses that an Nitrogen/Oxygen mix doesn't.

5-10 pounds, huh? 100 degrees F? It gets over that here in the summer. I think I would notice that.

[Wcross]

15. Ooops, forgot to mention we only used it in TBR tires.

TBR- Truck & bus radials. The normal inflation is 100-120 psi. The passenger tires (never tested those w/ nitro) usually only gain 3-5 pounds of air when warmed up.

[pokerfan]

17. OK, world makes sense now

Yeah, at the size and pressure of those tires, it makes sense that they would use Nitrogen. That's a whole lot of compressed oxygen in them tires.

[Wcross]

19. They are quite spectacular when they fail.

I have only enjoyed being in the test cell once when one blew. Even in the office area people would jump when one went off- it was always fun when newbies or visitors were there! That job convinced me to NEVER buy a convertible or linger too long next to an eighteen wheeler on the highway.

[DS1]

4. I understand it leaks less

but the only other useful application is in racing for the extreme heat.

Still, I've never seen a nitrogen pump, and I wouldn't bother anyway.

[pokerfan]

16. Consumer Reports did confirm that

there was about a third less leakage but stressed the point that both gasses leaked somewhat and Nitrogen is not an excuse to check your tires on a regular basis.

[AngryAmish]

5. They used to fill heavy equipment tires with nitrogen

(My pappy was a CAT mechanic) Anyway he told me they did it because it would not support combustion. It was a safety thing.

[pokerfan]

6. Yeah, that I can buy

but you never hear that used to justify it for average drivers.

[DainBramaged]

7. It's pure bullshit for normal people

If you don't properly evacuate the tire, or add air later on, it contaminates the nitrogen and makes the effect null. It is just another "100 mile per gallon" consumer scam.


If people would JUST check the air in their tires once a month and bring them up to the spec on the doorjam, their gas mileage would improve or at least not decline from the resistance of a low tire (s).

[pokerfan]

10. A buddy of mine bought tires from Costco

which came with Nitrogen. He was in the middle of nowhere when he noticed a tire running low. He pulled into a station and the gas jockey (they still have those in Oregon by law) said that they didn't have Nitrogen. My buddy said that it was ok and to just fill it with air. The kid said that he couldn't because the resulting mixture would be explosive! :rofl:

Yeah, you sure don't want to mix Nitrogen and Oxygen. :eyes:

[trof]

8. So...none of you guys rotate the air in your tires?

jeez

[JustABozoOnThisBus]

11. Sure. Every time I drive.

That air rotates like crazy!!

:rofl:

[pokerfan]

12. Only when it's time to change the halogen fluid

[DainBramaged]

13. After I balance the wizz pins and framus jam.

Every time.

[trof]

18. See my OP on the subject. It's important.

[DainBramaged]

20. I did, that's why I equalize the wazoo brackets too.

[Blue_Tires]

21. it is used in most racing applications