Nitrogen Filled Tyres

[Dicky Blighter]

Had a couple of new tyres on the Skoda last Friday and was suprised to be asked if I wanted them filled with Nitrogen or Air.
I know the boy racers swear by nitrogen as do F1 teams but always doubted if it made any difference as air is nearly 79% nitrogen anyway.
Man in the tyre place says it really does make a difference - less loss of pressure in winter, tyres run cooler and therefore last longer. Still somewhat sceptical but as it was free and they will top up free anytime you want I had it done and will see if it really does make a noticeable difference.
Anyone here use nitrogen and are you convinced it works?

[spunkymonkey]

Haven't used it, and not convinced at all that it's a real benefit for normal use.  The theory is that nitrogen doesn't pass through the rubber, whereas the smaller oxygen molecules do.  That's why a wel-fitted, newly inflated, tyre will lose pressure quite quickly - the 20-ish % oxygen will disappear through the rubber.  

But then you top it up (you do check your tyre pressure regularly, don't you?  ;D ) and add that 20% back, in the form of (roughly) 80% nitrogen and 20% oxygen.  So the oxygen content is now 20% of 20%, or 4%.  On the second top-up that reduces to 20% of 4% which is 0.8%.  Your tyre is now filled with around 99% nitrogen anyway.  Which is why a well-fitted tyre that's been on for a while doesn't go down any more.

As for the running cooler etc - that only applies if you allow your air-filled tyre to run flat and don't check / top it up. Of course, if you're hairing around an F1 track, you don't really want to be pulling in for those top-ups or risk losing any pressure but if you drive like that on the road you deserve to crash and burn  8)

On the other hand, if they offered it for free, then absolutely no reason why not!

[willcolumbine]

It's a scam to get more money out of punters. As you say, air is nearly all nitrogen anyway. Also, they don't suck every last bit of air out of the tyres before filling with nitrogen so at best you're going to get about 90% nitrogen in there! But hey, if it's free, go for it!

[Deleted User]

[StagNL]

For normal road use it is as Old Triumph Guy suggests, equal to snake oil.   Better put: you won't notice any difference and you are not in a situation to benefit from it.  Heck, I'd wager that boy racers won't even benefit from it either.
Yes, nitrogen is bigger so will be less likely to seep through the pores in the tyres.  Doesn't happen overnight and as mentioned, proper maintenence (pressure checks) will reveal any pressure loss.
I can fill mine with N2 at work for nowt as we have a N2 generator thingy there but I haven't felt the need yet.
But hey, if you do notice a difference, let us know.  I'd welcome it if I was proven wrong.

The reason racing teams use it is thus:  Air, as you know, often contains moisture in it.  Pure N2 from a nitrogen generator will have no moisture.  When setting up the racecar one wants to be able to calculate what the tyre pressures and temperatures are going to be at race speed.  One wants these to be at their optimum performance.  Moisture (water) throws a spanner in the works for the air is of unknown humidity - air could come from any locale.   The moisture content is thus unknown and causes uncertain expansion rates therefore calculations become guesswork.   Much easier to fill with moistureless N2 and have good calculation.   Also less time is wasted figureing out the race pace pressures.  Time that can be put to good use elsewhere on the car setup.
Running a forced induction engine has similar results on predictability and consistency.

[spunkymonkey]

Nice bottle - almost enough to make me buys some ;D

It's a little harsh calling nitrogen for tyres snake oil though because it does work in very specific applications.  More like antibiotics for the flu - they do have uses, just not that one ;)

[Hugh]

2047 wrote:

Nice bottle - almost enough to make me buys some ;D

It's a little harsh calling nitrogen for tyres snake oil though because it does work in very specific applications.  More like antibiotics for the flu - they do have uses, just not that one ;)

Yes if you want to drive your Veyron at top speed on a track or race in a F1 car the rest of the time it's a con.

[TimW]

908 wrote:

Yes if you want to drive your Veyron at top speed on a track or race in a F1 car the rest of the time it's a con.

Hey Hugh

It's not a con if it's free! ;)

Hope your feeling better.

[Dicky Blighter]

Agree if it cost me it's a con but willing to give it a go for free, rather suspect I won't notice any difference. Can see the point with the moisture but I use a scuba cylinder to pump my tyres and thats filtered and dried air anyway.
Now if I filled the tyres with helium it's going to make the car lighter and therefore instant extra horsepower ;)

[Nick Jones]

I had a bit of fun baiting our local Quik Fit manager while waiting for them to not fix my AC.  Had to give up when I realised he didn't know (or care) that air is 78% nitrogen anyway.....  :-/  I always found air works well enough  :)

Nick

[Lord Sorbington]

Dicky_Blighter wrote:

Now if I filled the tyres with helium it's going to make the car lighter and therefore instant extra horsepower ;)

What if the car floats away?

[Hugh]

339 wrote:

Hey Hugh

It's not a con if it's free! ;)

Hope your feeling better.

Hi Tim if it,s free thats ok then I am ok and looking forward to Sat  :)

[Dicky Blighter]

sorbs wrote:

What if the car floats away?

Hadn't thought of that - means less grip on rear tyres so all that extra HP goes to waste  :(

[Richard B]

Dicky_Blighter wrote:

Now if I filled the tyres with helium it's going to make the car lighter and therefore instant extra horsepower ;)

Wow, think of the improvement in unsprung weight!

[Deleted User]

I was told that Vauxhall do all new cars with Nitrogen as standard, its also on the Kwick Fit web site http://www.kwik-fit.com/tyre-technology.asp

[gilesdive]

Aircraft tyres are sometimes filled with nitrogen. If there is a fire caused by overheating brakes or similar, when the tyre pops, instead of suddenly getting a nice fresh supply of oxygen, it just gets a faceful of inert gas.

[Deleted User]

Soooooooooo………


My Vit like all Vits is rather front heavy


Soooooooooooo……

If I fill my front tyres with helium will it give me the perfect 50/50 balance? 8)

[Lord Sorbington]

Kwik Fit automatically assumed that I'd want my Audi's new tyres filled with Nitrogen and charegd me £1 per tyre for it.

If still rides as if it has square wheels.  Maybe if I transfer the original 1969 air from the tyres of my 2000 (I had it captured and put into the new tyres) the Audi would have a better ride?

[Dicky Blighter]

bobyspit wrote:

I was told that Vauxhall do all new cars with Nitrogen as standard, its also on the Kwick Fit web site http://www.kwik-fit.com/tyre-technology.asp

From Kwik Fit link-
'Nitrogen is completely safe. And by using it in a mixture with oxygen ........'

Nitrogen mixed with oxygen? that'll be called air then ;D
Try breathing just ntrogen and see how safe it is then  :(

[ferny]

I like this bit;

"And by using it in a mixture with oxygen to inflate your tyres the theory is that it’s possible to negate the issue of slow deflation, which is caused by oxygen slowly infusing through the tyre wall from the atmosphere."

Erm, so they advertise that your tyres won't go down, but fill it with stuff which they say causes it? ;D

[Deleted User]

Dicky_Blighter wrote:

From Kwik Fit link-
'Nitrogen is completely safe. And by using it in a mixture with oxygen ........'

Nitrogen mixed with oxygen? that'll be called air then ;D
Try breathing just ntrogen and see how safe it is then  :(

Roll up! Roll up!

Get your Kwik Fit special Nitrogen-Oxygen gas! Only £1 a bag!

[spunkymonkey]

Mmmmm, Kwik-fit  :-/

Following on from the same quote from that link:

Quote:

And by using it in a mixture with oxygen to inflate your tyres the theory is that it’s possible to negate the issue of slow deflation, which is caused by oxygen slowly infusing through the tyre wall from the atmosphere.

Now, maybe I'm reading wrong but surely the phenomenon of "oxygen slowly infusing [...] from the atmosphere" would cause your tyres to magically inflate by themselves?  I can see why diffusion to the atmosphere might be a theoretical problem, but the simple matter of percentages will negate that in a few top-ups anyway!

If the Schumacher Wannabes out there want to pay extra for stuff like this then fair play for selliing it.  I just wish they wouldn't debase science in the marketting like that - why not be honest and run a campaign like:

"Nitrogen - you'll think you feel the difference cos it cost you more than air"

[Deleted User]

2047 wrote:

M
Now, maybe I'm reading wrong but surely the phenomenon of "oxygen slowly infusing [...] from the atmosphere" would cause your tyres to magically inflate by themselves?  

No, the tyre is at a higher pressure than the surrounding air.

[Clive]

And why would that stop it?? I am guessing they are relying on osmosis ;)
Pressure differential? pah, that's nothing compared to the go-fasterness of the blurb.

[spunkymonkey]

380 wrote:

No, the tyre is at a higher pressure than the surrounding air.

I know that and you know that, but that would cause oxygen to diffuse from the tyre, not  infuse from the atmosphere.  The two are exactly opposite in effect because infuse and diffuse are equivalent here - both indicating a movement of gas in the direction stated  :P