R36 - Nitrogen

[R36Driver888]

My fellow R36 owners don’t be fooled by the title…

Due to some recent rim damage ( I wish Brisbane had proper drive ways) and that workman cleaned up after themselves as I believe someone in Brisbane is missing a nail..

During the repair the salesman talked up the benefits of using nitrogen to fill up your tyres… I must say at first I did not notice anything but I do now see between a 30 – 45km gain when it comes to refuelling plus it supposed to promote even tyre wear which is a good thing given the replacement cost…

Anyway food for thought my friends.

[Swallowtail]

Call me a cynic, but how on earth can nitrogen in your tyres (assuming a constant given pressure) be proven to improve your fuel economy by 6 - 8%?

As you say food for thought, but nothing I have read to date has convinced me of the value. Just my 0.02...

[R36Driver888]

Call me a cynic, but how on earth can nitrogen in your tyres (assuming a constant given pressure) be proven to improve your fuel economy by 6 - 8%?

As you say food for thought, but nothing I have read to date has convinced me of the value. Just my 0.02...

I am just quoting on what i am seeing on the dials... ( It should be noted that this is not based on city driving ) Brisbane to the GC and back twice a week..

I'ill give you change for you 0.02!

[passatpout]

My old man had nitrogen-filled tyres on his Merc, and didn't notice much of a difference with it running his normal day to day stuff. The big thing was that the tyre caps were green.. but he also wasn't going to go to the hassle of keeping a nitrogen cylinder at home for checking tyre pressures.

There's a few reasons why I reckon it's not worthwhile..

First up, standard, normal, everyday breathing air comprises around 79-80% nitrogen, around 20% oxygen, and the rest is other gases such as carbon dioxide, helium, etc, in trace amounts.

Secondly, the tyres (at least my Dad's) weren't evacuated prior to filling with nitrogen, which means that a fair proportion of the gas within is air, rather than pure nitrogen. I'd also hate to think what damage would be done to tyres if a vacuum was drawn within them anyway.

Finally, from a gas/thermodynamics perspective and ideal gas law, there isn't much difference between air and nitrogen anyway from a behaviour perspective.

[blutopless2]

i think the main reasons for using nitrogen in tyres is...
its dry... moisture in the tyre speeds up degredation.
more pressure stable... less pressure fluctuations and slower migration of gas through the tyre.

[Timbo]

You're noticing a placebo effect...maybe even contributing to it. The reality is that unless you are completing the exact same drive under the same conditions a whole range of factors might be at play. Perhaps previously your tyres were simply under-inflated?

Consider this in relation to nitrogen inflation: for it to have any real effect (given normal air is 73% nitrogen) the tyre fitter will have had to have removed ALL the air in the (deflated) tyre before filling it with nitrogen. In practical terms, that's not easy to do and I'd need to be convinced the corner tyre store had the equipment to do it.

I suspect the 'nitrogen inflation' is a way for tyre stores to gather a few more $s in a low margin business, and that's really the summary of benefits.

[Maverick]

i think the main reasons for using nitrogen in tyres is...
its dry... moisture in the tyre speeds up degredation.
more pressure stable... less pressure fluctuations and slower migration of gas through the tyre.

And those things matter if you're filling a race car or aircraft tyre where you want 100% consistence and cost is not an issue. Not so much a car tyre mounted on an alloy wheel.

In the car as the remaining 20% of the gas leaves the tyre (leaving the nitrogen behind) you refill with more air from the servo which mixes with the now enriched nitrogen content and so on so the tyre should end up a higher proportion of nitrogen each time you fill the tyre.

There is a heap of research available on the interweb that will confirm that nitrogen in cars is a waste of money as it offers no benefits and is just a money maker for the outlets that sell/push the product.

During the repair the salesman talked up the benefits of using nitrogen to fill up your tyres… I must say at first I did not notice anything but I do now see between a 30 – 45km gain when it comes to refuelling plus it supposed to promote even tyre wear which is a good thing given the replacement cost…

The gain will be related to the tyres having more pressure in them than before (ie before you had them refilled they were a lower pressure and/or your driving style changing and/or the engine has settled in). Nitrogen can't offer better fuel economy, your tyre is either inflated to the correct pressure or it's not and it's no substitute for regular tyre checks.

[Preen59]

Ok now i'll have to go back to my Kart racing days..

We tried Nitrogen and there was a vast difference between regular (atmosphere) air and pure Nitrogen.

I was a skeptic too beforehand, considering the fact that ~75% of atmospheric gas is Nitrogen...

It makes a difference- A hell of a difference.

I used it for around 12 months of solid racing at a lot of big meetings etc. What i did was wrap a ratchet strap around the tyre with the valve removed and squash it in as much as i could, to decrease the volume inside as much as possible, refit the valve, then inflate with nitrogen.

What i found was that you would go out with cold tyres (at lets say, 22 in the fronts and 24 in the backs) and normally you would come in at 24/26 hot if you had the setup sweet and the track had some bite. That was as close to cold pressure as you were ever going to get.

Now, throw in some nitrogen.. I found that the hot pressures were generally about .5psi higher than cold, and the tyre was more consistant throughout the session. This meant that you could go out with "hot" pressures and have good grip early without frying the tyres and having them go off mid race.

End result was it worked on a hot day when there was some grip down and was absolutely useless in cold weather on a cold track (never even bothered trying it in wets!). After a while i went back to using normal air again as i really couldn't justify the expense of the bottle rental etc for the marginal advantage it gave me..


Anyways, i don't know what it will do for street tyres as i've never been bothered to try it in them (I think its a waste of time), but it definitely does make a difference and quite a noticeable one.

[Swallowtail]

I'm confused... - "a hell of a difference"... "useless in cold weather"... "never even bothered trying it in wets"... "went back to normal air"... "couldn't justify the expense"... "marginal advantage"... "quite a noticeable difference"...

Or is it you that seems confused? LOL...

[Maverick]

I'm confused... - "a hell of a difference"... "useless in cold weather"... "never even bothered trying it in wets"... "went back to normal air"... "couldn't justify the expense"... "marginal advantage"... "quite a noticeable difference"...

Or is it you that seems confused? LOL...

You missed "I think it's a waste of time" and "I don't know what it will do for street tyres" and "never bothered to try it"