Nitrogen filled tires

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It is a myth that nitrogen isn't effected by temperature. It follows the ideal gas law like every other gas. PV=nRT temperature goes up, pressure goes up.

The "R" value is a correction factor (since no gas is actually ideal).

R for Air = 0.287 kJ/kg.K
R for N2 = 0.297 kJ/kg.K

so very small difference if any when it comes to pressure change due to temperature. If you filled 2 of your tires with N2 and 2 with air (clean and dry) you wouldn't be able to tell the difference by looking at the pressures on your dash display.

Nitrogen also holds moisture just fine, but is typically delivered "dry" in cylinders (or generated on-site), so you don't need to worry as much about the oily wet air from a poorly maintained and abused shop compressor (this is probably the biggest advantage to N2 fill-ups).

Finally, just think about this, if O2 does leak out faster than N2, then wouldn't you essentially be left with just N2 after refilling your tires a few times since the O2 will leak out faster leaving the N2 behind? So don't pay for what will happen naturally.
That's why I said "the theory" behind using it. I didn't say it was true, lol
 

RST Dana

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Michelin must like nitrogen. When we lived in SC, a friend that worked at a plant told me Michelin has a free nitrogen station in the employee parking lot. I took all my vehicles over as well as my bicycles. I’m not sure if it made any difference, but I gave it a go.
Tire Discounters here in Ohio offered it when we arrived here. Since our arrival, cost/maintenance has some locations to no longer offer it for free. Mgr said once the equipment has any issues, it is removed.
 

bill1013

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This is like the octane debate. Some say higher octane, premium gas, is a total waste of money. Regular gas is better on the wallet and the higher octane doesn't really improve your mileage or engine performance. It comes down to a matter of choice of the consumer. I, for one, use the higher octane on the premise it burns cleaner, gives a little extra boost in performance and helps keep the engine cleaner. I get 15 MPG with 87 and 18 MPG with 92. My choice. As to whether air is better than nitrogen it's the same. There are some advantages, whether small or imagined. As I've previously stated they use nitrogen on aircraft because it, supposedly, doesn't contain or hold water and it is non-combustible. If I owned a multi-million dollar plane, or any vehicle of that cost, I would go with the nitrogen as it is readily available in the industry. Why would I "cheap" out and used compressed air as even if you run it through dryers and separators you never get all the water out. So it all comes down to personal choice, cost and market availability. I would suppose if it were cheap & widely available I would use it, but until then I'll stick with air and deal with it's repercussions when they occur. Aloha!!
 
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I use nitrogen as a shielding gas when I weld. I also use it to pressure test HVAC lines for leaks or while brazing HVAC lines to keep contaminants out.

Never in my tires though
 

grouch

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Nitrogen is something that was used for a reason then the marketers got hold of the idea. Yes, it does expand less than regular air, although regular air is 90% or more Nitrogen. However, if a car is on fire, the tires will expand and as the outside burns thinner, they explode. With pure Nitrogen, it won't give extra oxidizer (oxygen) to the fire. It blows the flames around, but it doesn't add to them. It might even slow the fire by a minuscule amount.
 

rlistenb

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Nitrogen filled tires are certainly better than 'plain air'. Is it worth the price? Totally depends on the price and the person.

The molecules are larger so tire holds air better as they age but the main benefit is simply that your tire pressure does not change much with 'hot' vs. 'cold' tires. When my vehicle had this, I had tire pressure within 1 'pound' from a cold start in winter through a long drive. In the hot Texas summer, it would move as much as 2 'pounds'. Very little considering normal 'air filled' moves 5-6 'pounds' on a 1 hour drive during the Summer.
 

EddieC

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I scoff at the nay sayers that don't have first hand experience.

Nitrogen has been a good thing for me. Our '08 wheels were becoming an issue with slow leaks. My tire dealer fixed them twice for no charge and the problem just came back 6 months later each time. I had the choice of replacing the corroding alloy wheels with new "take-offs" for a pile of money or belly up for the $40 nitrogen treatment for all 4 tires with free top offs until the tires eventually needed replacing. My tire dealer said the nitrogen was the only dependable fix for my wheels and he was right. It's been 2 years now without any pressure loss.

So it IS a good thing but don't overpay. Like I wrote. $40 for the lifetime of the tires.

Here's a thought; what if the new rims are manufactured at a less than optimum quality control so nitrogen is needed in the new vehicles to minimize leaking?

Anyways, spending $75,000 and up and probably well over list price by choice, so $50 to $100 more is the breaking point?
 
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rico387

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Nitrogen matters in race car tires. They operate within such an extreme envelope that an adjustment of a half pound of air pressure is a significant change.
 

Hrocks

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Nitrogen matters in race car tires. They operate within such an extreme envelope that an adjustment of a half pound of air pressure is a significant change.
Exactly. I used to do a lot of track events back in the day. It's like any other sport...if you get proficient enough at it, very minor adjustments can make a "big" difference in performance. Running on a road course at 10/10th with race tires, one can really feel the difference of a couple of PSI gain after a number of laps. Unfortunately, I couldn't afford, nor did I really need nitrogen. It would have been a fun bench racing bragging point. As an amateur you simply learned what each tire needed in terms of cold air pressure. You knew that you were going to pick up 2-5 PSI depending on the track temp and the tires you were using. Although I retired from track events, I now use nitrogen!! I've bought my tires at Costco for about the last 10 years, and they automatically include nitrogen, balancing and lifetime tire rotations (includes rebalancing) every 6k miles.

I would agree 100% that the dealer "green cap" upcharge is a major rip off. I guess they had to come up with some new add ons after they had to abandon Scotchgard.
 

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