Mazda Rotary Club

General => General Technical => Wheels & Tyres, Suspension & Brakes => Topic started by: peterwolds on February 15, 2010, 09:39:31 AM

Title: nitrogen
Post by: peterwolds on February 15, 2010, 09:39:31 AM
wifes just had new tyres on car garage has put nitrogen in,said doesnt leak-constant temperature-better mileage fuel consumption.
not heard this before , if works anything to help reduce petrol consumption will get in FC\'s tyres.
Title: nitrogen
Post by: colin777 on February 15, 2010, 09:57:21 AM
ya its very popular in oz, its like 20 bucks for 4 tyres but your right with what ya say
Title: nitrogen
Post by: trotter on February 15, 2010, 10:05:51 AM
Yeah, Pete.

Regular air is really susceptible to expansion / contraction with changes in ambient temperature (thats why tyre pressure goes down in winter and the feds recommend you check it). Nitrogen isn\'t affected as much so you get better mileage from running on correctly inflated tyres.

As far as leakage goes, you will still get some - nitrogen makes up 79% of air anyway so im not convinced by this argument tbh mate.

Either way, Nissan uses it in the new GT-R so you can make your own mind up!!
Title: nitrogen
Post by: peterwolds on February 15, 2010, 10:10:45 AM
£2.00 per tyre isnt bad T,done at hull exhaust centre
Title: nitrogen
Post by: Prof on February 15, 2010, 10:43:50 AM
I was wondering about this - the Police apparently use Nitrogen filled tyres.
 
The argument is that Nitrogen molecues are larger than Oxygen molecules and so less easily pass through the porous rubber of the tyre under normal inflation pressures.
 
But since Air is 4/5 Nitrogen anyways, you could probably achieve the same goals (fuel economy) by just checking tyre pressures on a regular basis.
Title: nitrogen
Post by: d6277n on February 15, 2010, 01:29:00 PM
I\'m with Prof on this one - nitrogen is the main component of air and as a gas it will still undergo volume changes with temperature. You wouldn\'t expect them to be that different to those in air either.

You might see less oxidation of the rubber compounds inside the tyre over time (not that this is a major problem), but I really can\'t see much point other than for garages to rip you off - and given how cheap bulk nitrogen is they really shouldn\'t be charging extra. Oxygen is so similar in size to nitrogen that I wouldn\'t have thought there would be a detectable difference in diffusion rate either.

If you\'re looking at some ultra high performance application (F1, say) then maybe - as it\'s a pure gas it will be easier to model the pressure changes when you want to simulate it and it is likely to be more predictable in it\'s behaviour, but for a road car...?

Chris.
Title: nitrogen
Post by: HypoThermia on February 15, 2010, 02:08:49 PM
If you\'re happy with the results and are willing to payy then not a problem.

Having said that, a top up is all you\'re getting. There will already be air/water vapour in there from the tyre fitting, I doubt they collapsed the tyre to 0 psi to remove it...

Ian.
Title: nitrogen
Post by: Jono FD3 on February 15, 2010, 09:01:39 PM
Quote from: HypoThermia;672537If you\'re happy with the results and are willing to payy then not a problem.

Having said that, a top up is all you\'re getting. There will already be air/water vapour in there from the tyre fitting, I doubt they collapsed the tyre to 0 psi to remove it...

Ian.

This is very true matey!!
The only way around this would be to fit the tyres in a seald room which is filled with nitrogen, but then dreathing may be a problem:Yawn
Title: nitrogen
Post by: clive on February 15, 2010, 09:38:45 PM
As far as I know Nitrogen or pure air is used to stabilise tyre pressures because as the heat builds in the tyres the pressures go up partly due to the (contaminated) air inside which when your racing can lead to a change in the handling characteristics of the car. i.e. more or less under-steer or over-steer.

In Nascar special tyre bleed valves have been used in an effort to bleed off the increasing tyre pressures that build in the course of a run in an effort to give a more stable predictable tyre.

One of my own cars was a pig for tyre pressures and half way through a race the handling would change quite dramatically and for a lot races it slow the car considerably in "part two" of the race till we learned to compensated for it.

Personally I would say that having normal standard air in the tyre will increase fuel economy because as the pressure builds this leads to less contact area and less rolling resistance and thus better fuel economy.

So where does this leave us ?,

Well if you have just won your 56 million and have last years F1 Mclaren to play with, then go for it so you don\'t crash when the tyres heat up

However if you have a road car take two ten pound notes and put one in each ear to keep you from hearing the sales idiot from telling you to buy the latest money saving gimmick  :Giggle:Giggle

(hope this helps)
Title: nitrogen
Post by: AtomicRex on February 15, 2010, 10:12:34 PM
I\'m with Clive on this one...dont bother!
 
I use the stuff in my own race car....and the effects are amazing!  Standard air contains moisture....and it is this that causes huge pressure differentials within a race.  So predicting the ideal tyre pressure becomes a guessing game, and involves starting 5-10 psi below ideal on the opening lap.
 
One would hope you aren\'t driving the same on the road as we\'d be driving on track, so I doubt you are going to see the same extremes.  Stick the money in the tank, and go have some fun :)
Title: nitrogen
Post by: AndersE on February 15, 2010, 10:39:36 PM
Nitrogen is used in some emergency vehicles, and in racing also. One positive effect is if in an accident there is a fire, the nitrogen suffocate the fire. So nitrogen is all positive.
Title: nitrogen
Post by: trotter on February 16, 2010, 08:53:48 AM
Quote from: AndersE;672676Nitrogen is used in some emergency vehicles, and in racing also. One positive effect is if in an accident there is a fire, the nitrogen suffocate the fire. So nitrogen is all positive.

Assuming that the fire blows the tyres out I presume? (Which I grant you in most cases will be true!)
Title: nitrogen
Post by: AtomicRex on February 16, 2010, 09:10:30 AM
Yeah but fart and house fire come to mind!
Title: nitrogen
Post by: trotter on February 16, 2010, 09:19:17 AM
Quote from: AtomicRex;672720Yeah but fart and house fire come to mind!

*sniggers at the back*
Title: nitrogen
Post by: peterwolds on February 16, 2010, 09:44:09 AM
Quote from: trotter;672714Assuming that the fire blows the tyres out I presume? (Which I grant you in most cases will be true!)
might be useful for you T after your blow out :rollin
Title: nitrogen
Post by: trotter on February 16, 2010, 12:24:22 PM
Quote from: peterwolds;672733might be useful for you T after your blow out :rollin

Unneccessary *Mod Edit* ;)