I would put some scientific explanation here as well because i was very skeptic about this subject as many say it's useless and did some deep research to find out what is really up with this thing and when/where is it good for. This is what i found out and how i explained it for myself.
How Nitrogen differs from air(consisting of 73% of nitrogen) - Air has Hydrogen in it, in low quantity though, but still.
Now the big difference comes into play in moist and/or hot climate, as condensation water accumulates in compression tanks, it does so in your tires as well. In extreme cases tire techs have even found bucket of water in a tire used for 4 years after taking off from a rim(figuratively speaking).
This water or moisture(depending how long and much there are in your tire) is the main concern, this is what makes tires heat up more slowly, unevenly, change pressure big time with temp changes or even unbalance your tire going sub zero temps(READ: minus temps in C).
So you will have biggest benefits using Nitrogen in your tires when you live in England, where it rains every other day :D
And least benefit in eg Egypt or somewhere in middle of desert on a sunny dry day.
gains from nitrogen
*even and very fast warm up for tires
*even wear
*more stable pressure through out very big ambient temp changes(example from +30C to -20C)
*and debatable but possible, scientist say that because of Nitrogen molecule being bigger, it doesn't escape the tire from microscopical holes in rubber form so fast than Oxygen does.

You do realize that all of this is complete nonsense, used as pseudoscience to market nitrogen filled tires. Not sure what your point of hydrogen being in the air is, but the amount of free hydrogen not bonded to water in the atmosphere is so minuscule its a non-issue. Tire warmup would be the exact same as atmospheric air. The issue of water in the air is resolved by air driers that are installed on most shop compressors. Having a bucket of water in a tire is silly because you would certainly feel that driving down the road and most peoples tires don't last 4 years to begin with.

Nitrogen fill is snake oil that tire shops use to try and up-sell you to increase profits.

I did an experiment with Nitrogen and race tires for a college class a couple years back. I have a lot of data that proves and disproves a lot of BS about Nitrogen filled tires. I figured I would pick a few quotes to reply to and then share a little.
Pretty much this, but let's be specific. First, the whole point of using "pure nitrogen" is that it is two things: A large(er) molecule and a dry molecule (not part of H20). The very very very very very tiny difference between pure nitrogen and "regular air" is that the other gasses that make up regular air smaller molecules and they are molecules that naturally bond/attract/create moisture.

So why do we want dry air or pure nitrogen? That gets answered below.
Been to Phoenix in August? Dry "air" is pretty easy to find. But all joking aside, even if you could scrub all moisture from the air OR you're using a tank of pure nitrogen it's all sort of irrelevant. Explained below.
This right here. But the claims below are proven wrong in testing or should be further explained (RED):
The science is sound Malt, it's the practicality that isn't.

So I did testing with multiple 100% pure nitrogen tanks, 3 sets of race tires, multiple race weekends, tires that were dry mounted with dual valve stems for proper purging and ones that were mounted normally and I took every measure to ensure no moisture and no "regular air" was inside my race tires. I did comparison testing, session after session on multiple tracks/multiple weekends and back to back with tires that used regular air, lube-mounted etc.

NO DIFFERENCE, in fact sometimes the predictability in pressures was worse with the Nitrogen tires. But why? The answer is controlling the environment is practically impossible. Even with dry mounting tires, even with dual valve stems and lots of purging, it's insanely difficult to ensure not one molecule of moisture is inside that carcass and even if after all of that Nitrogen still expands/contracts with temperature pretty much just the same as regular, low-moisture, air. I'm sure that NASCAR and F1 teams are better at controlling what's in their tires and I'm sure they have different results but I also know, because Matchette explained it once that it's also a function of safety because Nitrogen is inert and not flammable.

I've scoured data from other racers/teams that have done the same testing, taken the same data and experienced the same results.

2 questions remain:

Question 1: So why do lots of racers have Nitrogen tanks in their trailers?

Answer: convenience. That's it. They are cheap to fill, and you can fill LOTS of race tires on 1 tank-full (like a 100 or so!). No pumps, no compressors. They are used because they 'simplify the weekend' and that's a very important function of racing; simplification.

Question 2: Is there ANY benefit putting nitrogen in my tires, especially if I'm not racing and don't care about the convenience of an air tank?

Answer1: Without moisture you greatly reduce corrosive properties that may exist to damage the inside of the wheel or the wheel rim, but this is not common enough to be much of a concern for most drivers.

Answer2: If you somehow are able to take the necessary steps to ensure no moisture and only 100% nitrogen are inside your tire then you may see a benefit on your daily driver where your tires won't deflate as quickly. However, due to how often we change tires, set pressures etc, the time frame to realize any benefits from Nitrogen's "large molecule" advantage will most likely not be realized. And when Malt says "Snake oil" that's why. The juice isn't worth the squeeze.

Answer 3: Long haul truckers who drive to lots of time zones and elevation changes and industrial machines. In this case they would use expensive machines to purge, measure and eliminate moisture from a tire while replacing the gasses.

Finally: I will be adding a Nitrogen tank to my enclosed trailer for the race track because I, too, like the added convenience. :D

I agree with everything you've said in principal with a few small caveats.

Yes, Nitrogen is inert and non-flammable. Air is non-flammable as well. What normal tire fills have is oxygen which is an oxidizer. That's sort of a silly reason to condone nitrogen fills though because compressed air is exactly the same makeup as atmospheric air, just under pressure.

BUT WAIT!... tires are under-pressure which means you get lots of oxygen if a tires blows, which fuels the fire right?! Not exactly. Not sure if any of you have much experience with vehicle fires and tires exploding due to flame impingement but the main concern there is the explosive force of the rapidly expanding gas, not the sudden on rush of normal air providing an oxidizing agent and nitrogen filled tires will have exactly the same effect as a normal air filled tire in that regard. I'm quite sure that I've dealt with hundreds (if not thousands) more exploding tires due to fire than 99.9% of the forum goers here. ;)

As for filling tires while at the track...

http://www.bicycletouring101.com/get...eFloorPump.jpg

Weighs less, takes up almost no room, free to use, no refill cost, no electricity requirements, not limited by hose length from the trailer, etc...

Far superior to electric compressors or carrying around gas cylinders IMO. :thumbup:

Race teams use nitrogen. Not because it's expensive.

But Jeez, don't put it in your street car. Buy flowers for the wife instead.

Unless your driving a race car or flying a plane, don't bother.

All in my opinion.

its free @ my costco and i can easily tell them to top off my tires. If it takes me the same amount of time at a gas station, i'll rather get it done with Nitrogen.

You have a pretty good sense of humor. Heck, speaking of simplicity, let's just inflate the tire by blowing in the valve stem with our mouths!

We'll, i don't mind opposition, as a reply to MALT and rice_classic, i do agree there are no significant benefits of nitrogen over dry air. But not every country and gas station have air dry system in their compressors, actually i would believe i haven't seen anyone using such in Estonia. Checking the weather channel i see relative humidity of 90%, so i don't want to fill tires with that air right now, considering the pressure and density rise in tire as it's compressed, therefore can hold less humidity and condense water starts to form.
But as for testing, maybe autoX is not the best Technic to test such thing, i would propose drifting to be much more adequate Motorsport because this is where tires get some heat, i myself, have measured measly 180 degrees C from 10-15min practice run. Sadly i don't have have proper weather to do tests myself(all icy and slippery - less heat buildup).
About someone running 4 years with same tires, quite common as not all people in a world drive 80k in a year because they live in much smaller country and don't have long distance travel to work daily, to get for an example, the tires this car ships with should last approx 65'000 km(yes i know, on a prius maybe), but still, now if you are some grandfather visiting his son every week and drive 50km for that. Some countries even see snow and have separate tires with rims for winter, again your summer tires should last forever - considering not drifting daily. So please, let's keep our minds and heart open toward fellow FRS/GT86/BRZ owners, we are all good, smart, all-knowing and beautiful.