33 replies to this topic

[Ethel]

Since air is about 4/5 nitrogen 2% is quite a huge difference - I wonder if it's down to water vapour

If you put nitrogen in a road tyre you wouldn't be able to convince the mafia you've drowned by sucking on the spare tyre valve after they've shoved your car off a pier.

Atomic weight of nitrogen 14, oxygen 16

[Teapot]

My neighbour paid £1 a pop for a squirt in each tyre (he has a Nissan saloon) at his service garage and was told it would improve the ride & handling, decrease tyre wear, improve fuel consumption and probably make the car invisible near speed cameras for all I know. I was wondering if it was like the "magnet on the fuel line" trick but from what people have said here I can see there is a basis of fact among the racing fraternity.

[mdickson]

We used to use it in the Civic race car when I was in Synchro. A lot of the BTCC teams use it as they don't have problems with the tyres having to get warm to get up to pressure as the pressure does not change dramatically with temperature. So yes they are an advantage if you are driving a race car but I don't think there is much point on a road car. I wouldn't use it in my wheels as they leak from time to time and dont want to waste the money paying for it.

[tuktuk]

a quid a tyre at kwik fits, thing is... how do you know what exactly is in youre tyre could be helium for all we know

[R1minimagic]

It's just a gimmick really for a road car, main benefit is less variation in tyre pressure as the tyres warm up which is quite important on a race car but pointless on a road car.

I think the pressure variation is more to do with water vapour in the air that expands as the temperature inside the tyre increases. Oxygen wouldn't have a measurable effect or nothing like as much.

Also a small benefit from a lighter wheel/tyre as nitrogen is 28 and oxygen 32 g/mol.

[level7]

Does anyone here add nitrogen when inflating their mini tyres? What proportion?

I don't mean nitrous oxide, by the way

every tyre I have is pumped up with nitrogen (I am currently working in refrigeration so I get it free) I use dry nitrogen and have never had any problems with it. The reason for using Nitrogen is because it it an inert gas so is not affected by heat so much (your tyres wont be at a lower pressure when its cold out) and so you use less petrol due to lower losses through low tyre pressure.

[cambiker71]

Have a read, it's not only for racecars...

Uniflate Nitrogen Info

[Robert]

I had the tyres filled with Nitrogen on my daily driver last time they were changed. It didn't cost much, so I thought I would give it a go.

I didn't notice any change in fuel consumption but I did notice that they require topping up with air slightly less often. In fact, the tyre place guarantee that they will hold their pressure for two years (at least for Summer tyres).

All in all, I'd say if it is cheap then it is worthwhile - but it isn't a must have.

[maggies_minder]

Does anyone here add nitrogen when inflating their mini tyres? What proportion?

I don't mean nitrous oxide, by the way

every tyre I have is pumped up with nitrogen (I am currently working in refrigeration so I get it free) I use dry nitrogen and have never had any problems with it. The reason for using Nitrogen is because it it an inert gas so is not affected by heat so much (your tyres wont be at a lower pressure when its cold out) and so you use less petrol due to lower losses through low tyre pressure.

anyone else find that level7 avatar eye catching lmao

Edited by maggies_minder, 31 March 2010 - 11:54 AM.

[Ivor Badger]

Since air is about 4/5 nitrogen 2% is quite a huge difference - I wonder if it's down to water vapour

If you put nitrogen in a road tyre you wouldn't be able to convince the mafia you've drowned by sucking on the spare tyre valve after they've shoved your car off a pier.

Atomic weight of nitrogen 14, oxygen 16

But you would be under the water with increased pressure, this would raise the partial pressure of the oxygen in the breathed from the tyre and more than negate the extra 2% nitrogen.

You have given the original reason for the use of N2 in your first sentence. Using dry N2 was attributed to the Williams GP team from around 1982 with KeKe Rosberg, (Nico's father). They used to fill the tyres with dry nitrogen to remove the moisture and reduce the tyre pressure difference from tyre temperature during the race. It seemed to give much improved speed towards the end of the race. There were no tyre warmers in those days.

[chappy]

as far as i knew (i read it about 5 years back in the legendary magazine that is MAX POWER! (i was young okay))

Air contains more water vapour than nitrogen. The vapour eventually gets through the tyre and so the tyre deflates faster, than a nitrogen filled tyre as there is less/no water vapour as there is not vapour to escape.


Hope that makes sense!

[R1minimagic]

Nitrogen is NOT an inert gas!! Lol

And your tyres will be at lower pressure when cold!

If you heat a gas up it expands, if you cool it it shrinks, ever heard of the Ideal gas law/Boyles law??!!

[Ivor Badger]

Nitrogen is NOT an inert gas!! Lol

And your tyres will be at lower pressure when cold!

If you heat a gas up it expands, if you cool it it shrinks, ever heard of the Ideal gas law/Boyles law??!!

What is Ideal gas law? Boyles law is volume/ pressure relationship

[R1minimagic]

pv=nRT

[alicetheauto]

It is LESS effected by temperature, I think, as someone put up exact figures earlier from first hand experience on the track. For a small (relatively) low powered car such as an a-series powered mini is it going to be that noticeable (especially on 10s or 12s) on a road under normal conditions? Nothing like as noticeable as a new set of plugs or an oil change! I think I shall save my 4quid and keep using air.