Nitrogen in tyres

[sapphireblack]

During a recent visit to an ATS for an AC regas I got talking to one of the tyre fitters. I learned they offer nitrogen tyre inflation for £2 a wheel. They told me the advantage of this is that it doesn't leak like air, meaning less frequent pressure top ups and checks are necessary, though I wonder what you do if not near a so equiped facility.

I always thought this was hogwash but maybe I shouldn't be so dismissive and invest £8?

As an aside, I still winch every time I see tyres placed upright on the outside face of an expensive alloy wheel when it's being 'soaped' for fitting. Not so bad with a new tye perhaps though even that's been rolled on the ground. Grit can Inflict nasty scratches which no tyre facility, other than wheel refurbishers, i've visited seems to understand. Their normal practice is simply bad practice.

[Leslie]

Nitrogen and oxygen molecules almost same size so should leak the same but oxygen can cause alloy corrosion though but remember air is mostly nitrogen anyway.
You pays your money and make your choice.
I put my refurbed wheels on cushions on the floor and watch over them and ask them to be very careful lol

[sapphireblack]

Points taken

I will never understand the mentality of an operator putting any tyre onto a possibly grit laden wheel and turning it to soap both side of the rims. With a grit laden tyre as well it's just painful to watch. I have my own methods similar to yours, but others would just laugh at the 'crazy old man'.

[Leslie]

They are only mint the once after refurb, removing of tyres is more risky to the finish I found than getting them fitted.

[sapphireblack]

They are only mint the once after refurb, removing of tyres is more risky to the finish I found.

True but i try hard to maintain that status.

I'd not mentioned if before but during the cars recent dealership visit, this happened

20221021_143537.jpg (128.79 KiB) Viewed 1811 times

All easilly sorted as it was a main dealer, they paid for its full refurb although I had to remove and refit the wheel as powder coating isn't undertaken by them, it had to be outsourced to the business who'd done the set originally. Overall not much fuss although a tad inconvenient.

[X5Sport]

Official guidance on the use of N2 Nitrogen….

Inflating tyres with nitrogen (N2)

All series
Situation:
The question is regularly asked, whether inflating the tyres with nitrogen instead of air has any benefit with respect to a ”gradual loss of tyre pressure”. This process is also known as diffusion (diffusion is the movement of miniscule particles, especially atoms or molecules).

Statement

Some companies regard inflating the tyres with nitrogen as a way of selling the customer a feature that has no practical benefit whatsoever with respect to diffusion. As nitrogen has larger molecules, it would indeed be logical to argue in favour of inflating the tyres with nitrogen instead of with air. However, the improvement achieved is only marginal because air is anyway made up of about 78 % nitrogen.

Composition of air:

78 % nitrogen (N2)
21 % oxygen (O2)
<1 % inert gases
0.03 % carbon dioxide (CO2)
The reduced rate in the drop in pressure inside the tyre is just a few hundredths of a bar over several months. Inflating the tyres with nitrogen does not relieve the driver from his duty (described in the Owner's Handbook) to check the tyre pressures regularly. Nitrogen is used in aviation and in motor racing because, in the event of an accident and the associated risk of fire, no additional oxygen should be fed from the tyres.

Affected vehicles:
All series
Procedure:

Recommendation

BMW does not recommend inflating tyres with nitrogen. Should individual customers wish to have their tyre inflated with nitrogen, their wishes may be accommodated.

[sapphireblack]

Well thats clear and concise, I'll save £8.00

[IanP]

I thought nitrogen was used in tyres as the pressure is more stable as nitrogen is dry. Dry compressed air would be as good for road vehicles

[X5Sport]

The key bit is as you say - the dryness. Wet air expands much more (liquid to gas expansion) and this is I think what gets missed in discussions. Dry air or dry Nitrogen expansion with temperature is about the same, but introduce humidity and all bets are off.

[Alan Gunn]

I get the use of the tyre machine at a m8's garage so do my own.
Admit it takes me ages and they laugh at me but i don't mind entertaining them 2 for half an hour lol.
Mine get Welsh air in them.

[StuBeeDoo]

I'm not great at sciences, but to me you would only get any benefit if the tyre were to be fully evacuated of air before filling it with nitrogen. I've seen my local tyre place do "nitrogen fill" and the operation is just the same as normal air fill.

I'll get my coat.

[X5Sport]

I'm not great at sciences, but to me you would only get any benefit if the tyre were to be fully evacuated of air before filling it with nitrogen. I've seen my local tyre place do "nitrogen fill" and the operation is just the same as normal air fill.

I'll get my coat.

Spot on, and you’d have to find a Nitrogen pump (or have your own supply) every time you needed more added when (for example) carrying a heavier load - kids, outlaws, cement, patio slabs..

[Leslie]

Anybody want some snake oil I have a few gallons lol

[StuBeeDoo]

snake oil

That ^^^ was my first reaction when I started reading this thread.