View Full Version : Nitrogen Tyres

21-08-2003, 04:40 PM
a thing in my junkmail recently had a special offer for filling ur tyres with Nitrogen. It says that it makes the ride smoother/better etc and they dont need to be topped up as often etc.

I've never heard of doing this before . Has anyone else ? and do u know if its actually worth the $$, or a crock of ****e ? The pamflet didnt have a price so i dont know how much, it just had a deal to get ur fifth tyre done for free.

Somehow a tyre full of nitrogen next to my fuel tank doesnt sound like a good idea to me :?

21-08-2003, 04:49 PM
see here!


Cosmo Dude
21-08-2003, 07:30 PM
The atomic Blah Blah may be that air bleads from tyres faster than Nitrogen. It is cheeper to check once a month at the servo than buy nitrogen.


21-08-2003, 11:44 PM
Yeah im running on nitrogen,have been for about 4-5 months now :P I took the car in for a pressure check last week which was recommended after a few months,and there was a few psi less than originally put in the tyres,which isnt to bad :P
I have noticed that the steering feels a little lighter,havent noticed much with the ride feel but :?
It cost me $4.50 a tyre to have them inflated with the nitrogen,which isnt that much really,and if its gunna save on tyre wear from less heat i think its well worth it,especially when riding on 18inch tyres :wink:
I wouldnt be worried about the nitrogen near you fuel tank Dogo,its not flamable(as far as i know),i think your thinking of hydrogen :wink:
I dont think they would be recommend it if it was dangerous,and had a risk of explosion,if it did why would they use it in the formula 1 cars which run highly flammable race fuel :P

22-08-2003, 09:24 AM
I had my tyres filled with Nitrogen when I got my last set of tyres on. The ride is definetly softer (easier for me to notice @ stock height i guess).

I was told a big speil about the benefits of Nitrogen, the main points were that it doesnt expand/contract like Oxy so in theory you should not have to add pressure at all unless you get a puncture of a bleeding valve.

It was only $5 a corner so if it means i dont have to fill the tyres up at the servo for 6mnths... meh $5 is nothing :)

Cosmo Dude
22-08-2003, 07:38 PM
Filled up my tyres and cost me$0.00
I would call it a placebo.


22-08-2003, 09:41 PM
All I'm gonna say is they could fill yer tyres with fart gas/helium/dope smoke and you'd be hard pressed to pick any difference on a road car with the exact same tyres back-back.

23-08-2003, 08:30 PM
Thats not true.
I also have the nitrogen in my tyres and there is a difference.
With 18" mags and 3" lowered the ride is noticeably softer which
was definitely worth $20 to me. If anything I think it makes the
ride a little too soft it gives a slightly pillowed driving sensation
I dont know if its just me being used to direct responsiveness of
Go-kart like suspension.


24-08-2003, 08:10 AM
sounds like a good idea then!

anything to make my ride softer on 18s goes into my good books :)

24-08-2003, 09:14 AM
my neighbour has a compressor for filling up his diving tanks with air. however as hes a deep sea/cave diver they dive using gas called nitrox. im not sure on % oxygen and %nitrogen but im guessing he could turn off the oxygen filter and get just nitrogen. ill ask him! haha those compressors are big $$ too

cheers mike

24-08-2003, 01:41 PM
OK, I gotta ask the question....

am not hijacking but....

If you want nitrogen to make ride softer coz your ride is too hard with the suspension/lowering/big wheels etc.....
Why the frig did you make is so hard in the first place??
*I'm clueless*

Please don't take offence, but it seems silly to me to make everything so hard and then have to make it softer again.......
I just don't get it......

Kitty in the 4WD Astina!!!


on a side note... completely irrelevant.... but if you get new tyres and fill them up with nitrogen, will the different chemicals react with the rubber, especially the side bits where the tyre is thinner? Am figuring that tyres are manufactured/engineered and designed with putting regular air in.... would the different chemicals in the rubber compound react differently with the higher nitrogen content? If as everyone says, that the tyres don't deflate or go down as normal tyres do, why?
Are the nitrogen molecules larger than air molecules and don't go through the 'gaps' in the rubber like air does? So, if they are larger and don't go through and air, which is made up of a cocktail of chemicals does go through......
doesn't the process of a tyre deflating and being filled and deflating and being filled mean that the tyre naturally 'filters' out oxygen, helium, hydrogen and the other gasses mean that your tyres are going to, by a process of elimination, end up with a higher content of nitrogen anyway? What other chemicals in air, as well as nitrogen, are too big to escape through the rubber? Is this part of why tyres crack? Why do tyres crack?

I have cracked.....

And have I essentially answered my own question?

Where is Dr Carl or Dr Julius Sumner-Miller or even Dr Deane Hutton from the Curiosity Show when I need them.......

Kitty the Konfused!!

24-08-2003, 02:17 PM
Hey Kitty ive said it b4 and ill say it again,get off the funny drugs :lol:
The reason the ride is harder is because when you fit bigger wheels you need to decrease the tyre profile to comphensate for the bigger rim to keep the speedo in correct calibration,so it makes the ride harder cause there is less tyre between the rim and road :P
And also the lower you go suspension wize the firmer the ride gets pretty much :wink:
So now you would be able to see why we would be prepared to try and make the ride softer by adding nitrogen :D
I dont think many of us are prepared to stay with our 14 inch rims just to have a softer ride,these are the sacrifices we make for a modified vehicle :D

24-08-2003, 02:38 PM
errrr just to ask a dumb question here....

If you replace the tyres and fill the new tyres with Nitrogen then surely you've removed your ability to make a accurate assessment over what is making things squidgier?

Don't get me wrong I can spount on about the benefits of using just about any gas but air for a 'track' or 'race' environment, but on the street where you have a far greater variance of surface conditions I doubt the worth, espeically as most of the benefits of the Nitrogen come up when you're running a tyre in a high stress situation with sustained high temperatures.

A street tyre simply isn't designed for that kind of application anyway and as such all you're doing is trying to band-aid the 'problem'.

Cooking a street tyre typically involves either not caring for it properly through underinflation OR having a poorly though out suspension setup that induces 'hot rings' ie uneven temperature across the carcass.

Oh and I'd like to think that people who take there cars and tyres seriously enough to pay $20 for an alternative filling gas would check there tyres at least once a forthnight to make sure that there's no slow leaks, dodgey valves etc .... Or even porous alloy or tyre...


24-08-2003, 10:35 PM
Er... what they said....

Now everyone is losing me....

(am going to ask Aaron later about some of his points but...)

I am not and do not say that everyone should stay with 14" to have a softer ride.

I can understand that bigger wheels and lowering the suspension make the car look better and the lower suspension makes the car handle better, but.....


Keep the terminology simple for me here.....

There has to be a mid point?

Yes modifying cars is compromise/sacrifice etc.....
But doesn't there come a point where your modification for handling improvement won't give you much extra unless you are booting it?
ie/ turbo etc? or racing?
(am having mental visions of Astina's out there taking on The Fast and Furious boys with flames and stuff..... :shock: )

I am way out of my depth now with my knowledge, but the point I was sorta getting at, was that

you take with one hand and give with the other....??

you take the softness out of your ride with bigger wheels and lowering your suspension

so you give by puttin nitrogen in your tyres...

I wonder if there is middle ground somewhere that is going to give you the best of all things without so much fussing.....

I do not say that what you guys are doing is bad/wrong/evil/satanic/insane(well maybe sometimes :wink: )
or in any way do I judge you.... quite the reverse, your cars are wonderful, and I am jealous :oops:

I am trying to understand what I thought I saw as an illogical chain of steps....

To me...
Wouldn't it make sense to get middle sized tyres, not stay at 14" or go to 18" but why not 16"?
Why go 3" lower from standard, but only go 1.5"?

I am genuinely asking here because I want to know what it is that makes the ride so Hard
(I read that to mean uncomfortable)
in the first place.
What changes do you make... what alternatives are there?
And is it only the nitrogen in the tyres that soften
(make more comfy)
the ride?

I am the gal that wants heated seats here....
how do you think my butt is going to react to a Hard ride??

:shock: :shock: :shock: :shock: :shock: :shock: :shock:

Kitty the "heads too full it's gonna explode" Kat

24-08-2003, 11:13 PM
Three main reasons why people lower their cars.
1 Better cornering due to less body roll, this is also the cause for a harsher ride because the springs are A. Stiffer (also to resist body roll and to stop the car from scraping the ground). B. Shorter which gives the car less distance to bounce (less of a cushion for the ride). C.To keep the wheels on the road.
2 for looks, we all now the standard Astina looks like a 4x4 and a lowered one looks Hot.

As for nitrogen and oxygen they are very similar elements. Nitrogen is lighter because it has 1 less electron, very small weight difference :!: . Still a softer ride could be felt through all four wheels. Does anyone know why nitrogen would keep pressure in tyres for longer???

24-08-2003, 11:46 PM
joely... The main reason people lower their cars is for looks...

They then reap the side benefits in handling.

Lowering a car doesn't imply or mean that you need to loose compliance in the suspension. Indeed many lowered spring sets sold 'off the shelf' are actually 'softer' for part of their travel than a stock spring in an attempt to make the car driveable when lowered att he extremes...

I could shuffle into the garage, dig through some boxes and find some of the texts I have on suspension and handling theory but it's too cold and I can't be bothered.

A car doesn't handle better if it's sprung incorrectly for the surface. Likewise if there's too much roll stiffness the car won't turn properly, either on initial turn-in or on mid-corner power application. The same applies on the opposite situations.

To move this post a little back on topic, the whole goal of making a road car handle is to strike a balance where the damper rates of the shocks can be adjusted (or lies by design) within the middle of the appropriate scale to suit the poundage (compression tension) of the springs. the tyres also perform this function as well. which is why sidewall construction and tyre pressure play such an important part in making a car 'handle'.

In theory 'air' in the tyres changes pressure more than 100% nitrogen does when temperature changes. ie heat air and it gets 2x as big whereas nitrogen may get only 25% bigger. (example only).

The tyres don't go flat becuase the molecule of Nitrogen is in fact larger than a lot of the molecules that make up air (air being Nitrogen, Hydrogen, Oxygen and Carbon mainly IIRC).

Think of it like this:
Air is a mix of sand, grit and small gravel
Nitrogen is a small gravel

Your rubber tyre is like a sieve or screen. (yes it has tiny tiny microscopic holes in it molecules and hence int he actual tyre).

If you fill the sieve the molecules smaller than the holes will flow or 'work' their way through it over time (becuase it has to gett hrough 5-10mm of layers of sieves) The grit and the small gravel won't. Hence it stays in the tyre for longer, why only longer? beucase theres always slightly bigger holes, contamination in the gas, chemical reactions breaking down the gas over time etc. Valves always leak a little bit...

If you kept inflating a tyre with air as it got lower you'd evenutally have a mix in it that was naturally higher in Nitrogen and other larger gas molecules than what leaks out....

25-08-2003, 12:01 AM
i get it except the small gravel and slightly bigger holes bit

04-09-2003, 10:05 AM
after having a chat to my neighbour (who dives using enriched nitrogen or nitrox as its better known) i now know that the air we all breathe and that comes out of your everyday airhose already contains 79% nitrogen!!!
how much diffrence that 21% makes im not so sure now

just filling everyone in!

cheers mike