http://tirenitrogen.typepad.com/techinfo/Ford%2520Baldwin%2520TireAging%2520%25232.pdf

Paper on oxidative tyre failure (Its specific to tread separation, but the conclusions may be generalisable)

N filling is mentioned towards the end. They find a 70% reduction in rubber degradation compared to air, so there's reason to believe it would extend tyre life IF you didn't normally wear out your tyres, which of course most people do.

It seems possible, though, that tyre performance/properties might be conserved better up to the point where they wear out.

As they point out, you can't get the oxygen below 5% without repeated purging, which I suppose the supplier/customer might not be willing to shell out for.

I don't know what the current situation is in the UK, but here in Taiwan some tyre sources supply it free as an aftersales service.

A Ford dealer I know tells me they have a "club" to supply N, for a one-off lifetime fee of 100NT. Thats about 2 quid.

I'm told if you have a Costco card they'll also supply N free even if you didn't get your tyres from them.

They can't be making money from that, but N is cheap to make (fractional distallation of air) and I suppose its a goodwill thing.

Edited by edlithgow on 11/03/2013 at 05:22

Collos25 wrote:

"Tests by the TUV in Germany show the opposite their conclusion it has no effect whatsoever. "

Interesting. You got a reference for that?

All I can find is

ec.europa.eu/enterprise/sectors/automotive/files/p...f

2003 TUV Report “Survey on Motor Vehicle Tyres and Related Aspects".

173 pages and N doesn't seem to get a mention.

(I havn't tried Googling in German, though, which I suppose might be necessary)

Hier, z.B.

http://www.berlin.de/special/auto-und-motor/werkstatt-inspektion/2119183-2215627-reifengas-ist-stickstoff-besser-als-druc.html

They say it only really makes any sense for high pressure tyres or when there is a danger of fire.

NO NO NO... you are all wrong.

It keeps my tyres in far better condition, they last longer through no oxidation and they run cooler.

the fact that I have to pump them up very two months so loosing all the ebenfits and replace them after three years is utterly irrelevant.

I FEEL I have done the right thing by spending money.. so I have..

:-)

Air works superbly and its free at most garages.

Well I have been using air in my tyres since 1974 and will continue to use it.

Even if pure nitrogen was significantly better than air you are only putting it inside the tyre, the outside still has to cope with good old fashioned fresh air.

I rarely have to top up my tyre pressures thus the much talked about loss of oxygen through the rubber is not significant enough to affect me in the real world.

Sunlight and ozone are the proven factors that degrade rubber but since most tyres are worn out before that becomes an issue after 6 years old I don't think it a topic worth discussing.

If nitrogen were really beneficial and became popular it would no longer be free. Garages charge for air on their forcourts.

The biggest danger to tyres after sunlight is car drivers.. Kerbing in particular.

I'd say running underinflated in particular. 66% with 1 or more tyres 30% under in this 2001 US survey. I'd guess you could get similar numbers in other countries.

http://www.nhtsa.gov/Cars/rules/rulings/TirePresFinal/FEA/TPMS3.html

That tends to undermine any "built-in" maximum age based on age-at- failure statistics, since a lot of the tyres will have been abused during thier service life .

As an (ex-)professional scientist, I have enjoyed this thread, with all the contributions from some masquerading as scientists.

As another (ex) professional scientist, I know that words (especially lots of scientific words) don't work with most people.

Lots of confidently expressed opinions here, hardly any evidence. Opinions are so much easier.

Here's some pictures.

(Animation of internal oxidative tyre failure. Scroll down to the middle of all those words. Its a bit slow, but then so's internal oxidative tyre failure.)

http://www.safetyresearch.net/safety-issues/tires/

Edited by edlithgow on 13/03/2013 at 14:44

As an (ex-)professional scientist, I have enjoyed this thread, with all the contributions from some masquerading as scientists.

As another (ex) professional scientist, I know that words (especially lots of scientific words) don't work with most people.

Lots of confidently expressed opinions here, hardly any evidence. Opinions are so much easier.

Here's some pictures.

(Animation of internal oxidative tyre failure. Scroll down to the middle of all those words. Its a bit slow, but then so's internal oxidative tyre failure.)

http://www.safetyresearch.net/safety-issues/tires/

Must be true if there are pictures and an animation.

There you go. (I love it when a plan comes together).

Well I have been using air in my tyres since 1974 and will continue to use it.

Even if pure nitrogen was significantly better than air you are only putting it inside the tyre, the outside still has to cope with good old fashioned fresh air.

I rarely have to top up my tyre pressures thus the much talked about loss of oxygen through the rubber is not significant enough to affect me in the real world.

Sunlight and ozone are the proven factors that degrade rubber but since most tyres are worn out before that becomes an issue after 6 years old I don't think it a topic worth discussing.

If nitrogen were really beneficial and became popular it would no longer be free. Garages charge for air on their forcourts.

I see why this is of little interest to you, and, I'd have thought, probably of little interest to the majority of drivers.

But here's the thing: Not everything is about you, (or even about the majority of drivers).

There are people who don't wear out thier tyres. They might keep a classic as a pet, or tow a trailer, horsebox or caravan occaisionally. They might have an off-roader or camper as a second vehicle, or they might just not drive very much, and/or drive fairly sedately when they do. Like me.

These people may be interested in stretching the life of thier tyres, and (despite the forcefully expressed opinions to the contrary) the evidence available to me suggests that an inert gas fill, perhaps in combination with an exterior UV/ozone protective coating, may allow them to do so.

Accordingly, I don't personally find your lack of interest very interesting. You are of course free to find my lack of interest in your lack of interest uninteresting, but if you post your lack of interest on every topic you are uninterested in, you'll either need to have very wide interests, or you're going to be very busy posting.

Well I appear to have hit a nerve here, think our friend from Taiwan or wherever must have the world monopoly in nitrogen.

For your info I own a classic which does about 2000 miles a year. I take the tyres very seriously since those 4 small patches of rubber are all that keep me on the road and alive. Putting nitrogen inside when they are surrounded with air containing impurities and moisture is pointless, painting unproven home made treatments onto them is just asking for trouble and is stupid. I do not even bother painting any of the special wonderful snake oil products on the market onto them, they are just a waste of money.

What I do is what every responsible car owner should do, When I buy tyres I ensure they are of recent manufacture and not old stock then I replace them after 6 years even though they will be only about 1/2 worn.

I then check the pressures regularly and check for nails, cuts etc, just like you should on any tyre.

The cost of a set of tyres is peanuts in comparison to the other costs involved with running a car, if you resent paying money to keep your car safe you should not be on the road, you are a potential danger.

The cost of a set of tyres is peanuts in comparison to the other costs involved with running a car .

Really? With some of the flashier models it can approach a grand. You must spend rather a lot if you only do 2000 miles a year?

Insurance £200

RFL £120 (6 months)

MOT £50

Fuel £400

Service (materials only) £50

Total £820 (plus any repair costs)

A set of tyres costs approx £300 thus over 6 years that is £50 a year. £50 is 6% of my other annual costs.

As I said, its peanuts.

On my road car a set of tyres lasts approx 30,000 miles if I rotate them front to back.

Over a year I spend the following

Insurance £250

RFL £30

MOT £50

Fuel £950

Service £150

Total £1430 (plus anyrepair costs)

A set of tyres is approx £600 which over 4 years is £150 a year,

Thus my tyres cost about 10.5% of my other fixed costs which is still very reasonable in my opinion.

Tyres look expensive when you buy a set but as a percentage they are small part of your motoring costs. Considering that they are your only contact with the road and have a very hard life personally I think they are cheap.

So from your viewpoint the nitrogen question is irrelevant, as you will replace your tyres long before they are worn out, at 2000 miles a year, or even 4000 ?

I am also conscious of the well-worn adage that tyres are one's only contact with the road, but I use my judgment (and my MoT tester's) to decide when to replace. On topic, using nitrogen is a foible.

Nitrogen is irrelevant in tyres regardless of the mileage.

I too use my judgement on when to replace and that is based on not only my own eyes but the advice from the manufacturers.

Its not just cracking that needs to be considered. As rubber ages it gets harder and grip deterioates. When I am out on the road I want a car that performs as safely as it can, on old hard rubber your safety is compromised.

Even on my daily driver I never let the tread war down to the 1.6mm legal limit.

So from your viewpoint the nitrogen question is irrelevant, as you will replace your tyres long before they are worn out, at 2000 miles a year, or even 4000 ?

I am also conscious of the well-worn adage that tyres are one's only contact with the road, but I use my judgment (and my MoT tester's) to decide when to replace. On topic, using nitrogen is a foible.

Sadly, the well-worn adage that tyres are the only contact with the road doesn't strictly apply in my case, since my cars tend to spend quite a lot of time supported by axle stands. They don't wear out either, though they oxidise a bit.

In contrast, the other well-worn adage, (worn treadbare in this thread) that nitrogen is irrelevant/a trap for the gullible, etc, is (apart from a reference in German) without visible means of support.

As I said before, the evidence seems to support internal oxidation as an important age-related tyre failure mechanism. Much of it comes from reports produced by, with or for the (US) National Highway Traffic Safety Agency.

[Search for “What NHTSA Applied Research Has Learned From Industry About Tire Aging” (MacIsaaac, 2003) if interested. Its a pdf of a powerpoint, and so may be more digestible than a research paper. I can't get to the URL]

Although they are a non-commercial organisation, I don't necessarily take them as an unimpeachable source. Their initial interest arose from the Ford Explorer/Firestone tyre failure episode, which may not be typical, and in which they were alleged to have been “asleep at the wheel”. As govt. bodies are wont to do, they lobby for more regulation (of tyre service life, for example). This might color their view of the evidence. They also seem to be more closely allied with motor manufacturers (in particular Ford) than with tyre manufacturers. This is natural, since tyre manufacturers have been hostile to service life regulation. OTOH, Fords fraught history with Firestone suggests they are anything but a disinterested party.

These caveats aside, this is the best evidence I've seen. If internal oxidation is a (or according to the NHTSA, the) main cause of tyre age-related failure, its intuitively likely that measures to prevent it will reduce the effect of tyre ageing. I've quoted research that supports this for nitrogen filling and for butyl rubber linings.

The other locally well-worn adage, that the outside of the tyre is in any case exposed to atmospheric oxygen, is true, but does not conflict with internal oxidation as a (or the) main failure mechanism.

This air is only at atmospheric pressure, and in operation the outside of the tyre stays cooler than the inside, so oxidation is slower. Since I generally run tyres at higher pressures than recommended by the car manufacturer, the pressure differential may be especially important in my case.

Inert gas filling may be a foible. At worst, it seems to be a harmless foible, and the available evidence suggests it may do some good.

I'm preconditioned to go with the evidence and discount unsupported opinion. If anyone is aware of contrary evidence (in English), I'd be interested in seeing it.

"Since I generally run tyres at higher pressures than recommended by the car manufacturer, the pressure differential may be especially important in my case."

So you know better than the manufacturers makes your other arguments a bit weak.

Nope. Its a simple fact.

It has no impact on the validity of my other arguments. Nor does your comment.

I think I'll give my case a rest at that, if that's the best y'all can do,

You can flog a dead horse underwater, but you can't make it think.

Edited by edlithgow on 20/03/2013 at 14:31

You could probably cut :"Well, it’s certainly true that I’m a “potential danger”. No argument there." out of context too, perhaps adding something clever like "Wow, yet another sensible comment".

(If you don't think it makes you look a bit of a prat, that is.)

Feel free.

Free here in Germany at every petrol station if you are so concerned about the cost you could always get a foot pump.Seeing the tyre has over 50% open to impure air putting nitrogen inside is a complete waste of money,thought up by tyre centres to relieve gullable people of a little more money.

Edited by Collos25 on 12/03/2013 at 10:54