Nitrogen in tyres

[jdrrco]

Our local tyre place offers "Free Nitrogen Inflation" for all tyres costing over £50.

Just as a matter of interest, what is the advantage, if any, of filling tyres with nitrogen?

 

[Seamster15]

Its lighter than air? I think!

 

[DieselE]

The coefficient of expansion of Nitrogen is lower than air. I guess the advantage is that they will be less sensitive to changes in temperature.

Apparently, aircraft tyres are filled with Nitrogen. So, if you're planning to take your E Class to the top of Everest it's Nitrogen for you. At ground level, I'd have thought the bother of having to go back to the garage to have them topped up would outway any advantage.

 

[scumbag]

its more to do with the moisture content in air. Air increases and decreases with humidity, so you dont get consistant pressure, with nitrogen you do. so if you check your tyres in the morning, then again at night you may see a difference. but it is minimal.

thats the reason its used in racing formulas. it will be of little or indeed no benefit to road car tyre performance.

thats said, i have it in mine and they do keep the pressuse at the same level without needing adjusting, but they didnt need adjusting with air in either. i just have my own nitrogen supply at home.

 

[jdrrco]

The coefficient of expansion of Nitrogen is lower than air. I guess the advantage is that they will be less sensitive to changes in temperature.

Apparently, aircraft tyres are filled with Nitrogen. So, if you're planning to take your E Class to the top of Everest it's Nitrogen for you. At ground level, I'd have thought the bother of having to go back to the garage to have them topped up would outway any advantage.

Was planning on conquering Everest in it, but not got winter tyres on at the moment...

Suppose there could be something to be said for the pressure remaining more consistent with less temperature fluctuation, but, as you said, every time you top up, you'd be reducing the proportion of nitrogen in tehm anyway.

Thankfully the dealer put new tyres (£145 each) on the car before I got it, so don't need to change them yet, but just saw it advertised and wondered what the point was.

Thanks for replies.

 

[Satch]

Nitrogen is retained better by rubber membrane tyres than oxygen which tend to leach out over time. Also no oxidation of the tyre internals and the nitrogen is dried so no water vapour either.

That is it really apart from a load of BS when people try to charge extra for Nitrogen fill. The expansion thing is a bit of a myth. Some effect but not material for normal beings as air is about 79% Nitrogen anway.

 

[pineer35]

it is if you think £50 is an advantage. ??

 

[grober]

Nitrogen purity?

I would be looking at the analysis certificate for the nitrogen supply. It may have some small print such as " may contain impurities including Oxygen, Argon, Carbon Dioxide, Water vapour and trace hydrocarbons!
but if its good enough for the space shuttle its good enough for me! http://www.airmichelin.com/space.html

 

[gaz_l]

Engage brain before typing..

Cheers,

Gaz

 

[mercmanuk]

the reason they put nitrogen in aircraft tyres is to stop possible blowouts on landing,my father used to work as service manager on a aircraft hanger at m/cr airport.all the fitters used to fill their car and motorcycle tyres with the stuff..

 

[scumbag]

Our local tyre place offers "Free Nitrogen Inflation" for all tyres costing over £50.

Just as a matter of interest, what is the advantage, if any, of filling tyres with nitrogen?

Tell you what. you can pop round to my house and i can fill your tyres for free with Nitrogen. then you can make your own mind up. Takes about 10mins.

Bring your own tea bag and you can get a cup of tea too. I charge rent on cups tho. £800 a drink! have had to put this charge up as the lowering weight by folding your seats ideas seems to be very unlucrative!

 

[springer]

Nitrogen

Hi there,

I would be interested to know what equipment you have that produces nitrogen or do you have in bottles.

 

[Dieselman]

My understanding is that nitrogen is used in tyres because it has better spring charecteristics than air. Some manufacturers fill cars off the assembly line with nitrogen I believe.

 

[Sp!ke]

I thoughs the molecules were bigger than air molecules so less chance of your tyres deflating over time.

 

[scumbag]

Hi there,

I would be interested to know what equipment you have that produces nitrogen or do you have in bottles.

Bottles? BOTTLES? thems cylinders, man!

I have 2 x 10ltr tanks of the stuff and a Harris reducer. Rented from Energas! it is connected to a standard tyre inflater jobby thing. its primarily for filling other stuff, but if you turn the reducer down to around 2 bar or so, up goes the tyres!

 

[jdrrco]

Sorry if I put this in the wrong place, but I thought that as it was about tyres in general rather than tyres on an MB in particular, it belonged in the "General" section.

My knuckles consider themselves duly rapped!

 

[JonLittlechild]

I do a lot of kart racing and the teams with real budgets use Nitrogen in their tyres (we don't, we're a poor team!). When you use air, you also get the moisture in the air into the tyre and the expansion of the moisture is very sensitive to temperature. This means that the pressure of the tyre is also very sensitive to the tyre's temperature.

In racing, the tyre pressure/temperature balance is critical to the correct functioning of the tyre - as little as a single PSI can add or remove significant time to your laptimes, so it's a balance that has to got right.

Because the moisture in the tyre causes the pressure to fluctuate with tyre temperature tyre pressures have to be set once the tyre is up to working temperature which on some makes can take twenty minutes (and this really needs to be done every few hours during testing). When you use Nitrogen, tyre temperature has a geatly reduced effect upon tyre pressure because you don't get the moisture in the tyre. The immediate benefit is that the pressure you set on a cold tyre is pretty much the pressure you get on a hot one. This means setup of the pressures is much easier, but it also means you've removed one of the variables (pressure) from the tyre pressure/temperature equation as you're driving which makes it easier to keep the tyre conditions consistant.

There may be other advantages to using Nitrogen but air is 78% Nitrogen anyway, so I would expect that the main advantage gleaned in the racing world is the moisture content issue.

Nitrogen in road cars? If it's free, why not. But you'd never notice the pressure consitancy benefits on the road. Maybe on the track, if your track driving was good enough.

Jon

 

[1998K]

I thoughs the molecules were bigger than air molecules so less chance of your tyres deflating over time.

I don't think so!

 

[JonLittlechild]

Air is 78% Nitrogen and 21% Oxygen. From a quick glance at a periodic table and a vague recollection of my a-level chemistry, I think Nitrogen molecules would be fractionally smaller than Oxygen wouldn't they? If so, the smaller molecule theory doesn't hold up.

Jon

 

[Satch]

Air is 78% Nitrogen and 21% Oxygen. From a quick glance at a periodic table and a vague recollection of my a-level chemistry, I think Nitrogen molecules would be fractionally smaller than Oxygen wouldn't they? If so, the smaller molecule theory doesn't hold up.

Jon

http://www2.ubu.es/quim/quimorg/polimeros/trab_pub/gas-meg.pdf

Ah yes, of course. Should have known that.

Oxygen seems to diffuse through certain types of polymer quicker than Nitrogen under lab conditions but in a road tyre? Who knows.

This seems pretty good common sense to me

http://www.bridgestone.com.au/tyres/products/car/care/nitrogen.asp

If it is free, fine. But unless using for a specialist applications not worth paying for.