Nitrogen in tyres.

[Deleted User 0001]

Howdy from the North. Just put nitrogen in all my tyres, recommended pressures. $30 at Bob Jane's. Go check after sale at any time, free FYI Nitrogen is an inert gas and does not increase/decrease with temperature, therefore only needs a check every 3 months, if that. Better tyre wear Ex. Aircraft Engineer

[Hillbilly]

The only thing that nitrogen does in car tyres is lighten your wallet. It is used in aircraft because it doesnt expand at height like ordinary air does. There is no noticeable benefit in your car

[staz88]

Yep, it's a cash grabbing gimmick.

[NuffNuff]

from memory on a track its more consistent in pressure rise due to heat. air is inconsistent pump to pump due to water etc

on the street, useless.

any water vapour or air ruins the fill

[alexaescht]

any water vapour or air ruins the fill

Haha yep, and I really doubt they pull a vacuum on the tires as they seat them on the rim to ensure there's no air in there before the nitrogen fill. Air is already mostly nitrogen so you're wasting your money paying $30 for a fill that's probably not even pure nitrogen.

[jimmedy]

I opted for Nitrogen when I got my tires switched onto to my new rims not long after delivery of my car - but it was 'only' $4 a corner, and so @ $16 I thought what the hell.

Now whether or not it's the Nitrogen or whether it's just that my tires are really well mated to the rims and my valves are great too - but I lost only 1 psi in 1 tire over the first 11,000 kms. The other 3 were at the same psi I drove away with on fitment when I went back for a rotate / balance / align.

I got them to bump it up further from 38 all round to 40 psi, which they did for free, and yet again, I checked at the servo the other day and they were only down at 39 after another 12,000 k's. I probably let more air out with the servo hose that got out of its own accord.

My rationale is that it gives me a little more predictability as I like to run the pressure very high but I don't want too many further fluctuations due to temp.

So, certainly I take the claims of the people making a lot of money off this with a grain of salt (and $30 seems a stretch). But for $16 I went for it... *shrug*. If anything they'll keep getting my business every 10,000 for my rotate / balance / align because their original fitment was top notch.

[Sydneykid]

As high school science tells us, atmospheric air is around 78% nitrogen, so there are no miracles in increasing that to 99.99% nitrogen. For example it won't reduce pressure drop over time, stop leaks or reduce punctures.

We use nitrogen in the race car tyres for consistency, as pointed out above there is variability in the air pumped straight from atmosphere, particularly humidity. The other, but related issue, for using nitrogen is the reduced pressure increase as a result of increases in tyre and wheel temperature. In some categories, during a race, we can expect upwards of 10 psi increase in pressure partially due to the separation (into hydrogen and oxygen) of any water vapour present. Using bottled pure nitrogen removes the possibility of any water vapour. In addition nitrogen expands at a slightly slower rate than atmospheric air. Hence we get 25% to 30% less tyre pressure growth during a race.


My view, there are good reasons for using nitrogen in race car tyres, not so much in road car tyres.


Cheers
Gary

[ill0gitech]

Nitrogen has a larger atomic size, therefore it doesn't leak as quickly as oxygen does

Not worth the money in my opinion, particularly when you get sales spiels like the above. "Bring your car in every three months" sounds like a way to get money out of you every three months, as well as "Oh, you need a wheel alignment" and "you're tread is a little low, so we replaced your tyres, that will be $2,000.
Whilst I'm interested in the observation from Jimmedy above, I don't recall ever having issues with needing to constantly check tyre pressure a lot, or considerable drops in PSI that wasn't related to a puncture.

[Hillbilly]

Unless you create a vacuum before you pump up with Nitrogen surely you are going to have a fairly large % of air in there already.

So why dilute the nitrogen and what advantage are you going to get whilst still having the air in there.

Seems like is all marketing to me.

[Sydneykid]

Unless you create a vacuum before you pump up with Nitrogen surely you are going to have a fairly large % of air in there already.
So why dilute the nitrogen and what advantage are you going to get whilst still having the air in there.
Seems like is all marketing to me.

For race car tyres we have several different processes. A simple double purge and refill gives 98% of the desired result ie; only leaves 2% of non nitrogen in the tyre. On some cars we have 2 valves, 180 degrees opposed, we fill from one with nitrogen while leaving the other open. That gives a 99% result. We also have an ex air con vacuum pump which when used to purge to minus 20 psi gives a similar 99% result. The results are judged by the tyre pressure increase when compared to a from zero fill (ie; at fitment) with nitrogen.


Cheers
Gary