Advanced Tyre Technology

[AMG4ME]

Advanced tyre technology has reached the public, last week I fitted my AMG CLK55 with Dunlop Sport SP9000's all round.
I was offered and accepted a Nitrogen replacement to the normal air inflation at an extra cost of £10.
I am trialling this, the benefits advertised are as follows.
1/ The tyre internal temperature remains more constant, less expansion and contration of the volume.
2/ Less likelyhood of tyre pressure loss, they say tyres require checking less often, about every three months, call me old fashion but I check mine at least once a week.
3/ Up to 25% less tyre wear, increasing the longevity of the tyre and decreasing costs.
4/ Increased fuel efficiency.
Sounds good, if it's good enough for Micheal Schmacher and Formula One technology then it's good for me.
AMG4ME
The car is averaging 27.8 mpg.

 

[zeberdee]

How Much!!!!

So do you spend most of your time driving on the limit?

1) Is valid, but only really if you're driving the car in such a way you get a significant amount of heat generated in the tyres. Pressure variation in a road car tyre is minimal compared to a race car. Dry air also has a more constant expansion / contraction rate since it is water vapour in the air that causes the undesired effects. (And is cheaper than nitrogen)

2) Is also true to an extent, but you still need to check your pressures regularly.

3) & 4) Are nonsense! The only benefit would be if previously you never checked your tyre pressures and consistently drove with under-inflated tyres.

So none of that is advanced tyre technology at all! Tyre technology is in the construction of the tyre and the compound of the rubber - that's when it gets interesting!

Enjoy your new tyres

 

[mlc]

two comments:

1. Why should a different gas in the tyre be less likely to leak?

2. If you can get 27 to the gallon out of this car youre not driving it right, just lend it to you uncle mark and I will get it down into single figures for you

Enjoy!

Mark.
1972 350 SL
2003 230 SLK
and a variety of Fords for the real world

 

[Myros]

the normal air we all use in our tyres

is about 80% Nitrogen anyway. Now if they had filled your tyres with laughing gas, that would make me smile. and you, when you checked the pressures.

 

[SLinKyjoe]

i have nitrogen in my tyres. cant be bothered in using a filter and compressor for drying air and normal garages dont dry it so air will expand and contract as a direct result of the humidity levels as well as ambiant temperature.

the only reason F1 cars have it is to reduce the effect that moisture so they can keep the tyres at a more effectively pressured level.

makes no difference to car tyres used on the road. i did mine coz i have some Nitrogen to do it with. and it went for a few laps of silverstone.

you still need to check your tyres regular. it will make no difference to wear or fuel economy. correctly inlfated tyres work not matter what gas is used to inflate them.

 

[Blobcat]

two comments:

1. Why should a different gas in the tyre be less likely to leak?

The Nitrogen atom is larger so less likely to escape through the rubber, or thats the theory. Sounds like snake oil to me .
Seen this on the web for £1.50 per tyre

 

[mlc]

The Nitrogen atom is larger so less likely to escape through the rubber, or thats the theory. Sounds like snake oil to me .
Seen this on the web for £1.50 per tyre

Err. this is a bit worrying cos this means that the Physics must have changed since I was a boy.

Air is approx 4/5 Nitrogen, 1/5 Oxygen and around 1% of assorted other gases. Nitrogen and Oxygen are next to each other in the preiodic table with Oxygen the heavier atom.

Unless their are other factors that I am not taking into account I would have expected the atom size to be very similar, what am I missing?

Mark.

 

[mioba]

If it isnt broken dont fix it.
Air has been used for hmm how long now with no problems. This Nitrogen thing just seems like someone is trying make money by fooling people of its "benefits".
IMHO

 

[jberks]

To quote blackcircles

Nitrogen has long been the accepted gas medium for filling aircraft tyres, racing tyres and heavy mining and construction vehicle tyres. Nitrogen is used for safety reasons and to ensure that tyres are always at a constant pressure. Compressed air, the traditional medium for inflating car tyres, contains both oxygen (21%) and nitrogen (78%).
The rubber tyre is like a membrane, through which oxygen permeates three times faster than the nitrogen. The result is that the oxygen slowly leaks out through the rubber walls, and the under-inflation leads to higher tyre wear with a consequent decrease in safety and comfort, and higher fuel costs.

So basically, if you check your tyres regularly there should be no problem and its not necessary.
However, it is an interesting point. How do you check your tyres? Every gauge I use gives me a different reading! I use a pencil gauge which is around 2psi less than the one on my pump. I assume the pencil gauge is more accurate but I don't really know. Either way, I'd rather be 2psi higher than lower and I don't inflate to the maximum figures. I tend to pick a value around the middle of the range. After all, it sits at 80 during the week and is a shopping trolly at the weekend.

 

[Myros]

next question

do the take the tyre off the wheel, and then take them into a nitrogen filled room to re-mount and pressurize them. If not, how can they ensure a 100% nitrogen fill.

 

[Blobcat]

Err. this is a bit worrying cos this means that the Physics must have changed since I was a boy.

Air is approx 4/5 Nitrogen, 1/5 Oxygen and around 1% of assorted other gases. Nitrogen and Oxygen are next to each other in the preiodic table with Oxygen the heavier atom.

Unless their are other factors that I am not taking into account I would have expected the atom size to be very similar, what am I missing?

Mark.

Oxygen atom size 0.14nm
Nitrogen atom size 0.15nm

That extra 0.01nanometers makes all the difference

 

[jberks]

Actually, according to the info, The nitrogen stays in the tyre and the oxygen seeps out (though I doubt the rubber make up is so specific that a 0.14nm molecule will escape but a 0.15 one will be trapped).

So, by simply topping up with a conventional compressor on a regular basis (as we all do anyway), over time, the oxygen content will reduce as the molcules escape and proportionately and we end up with a nitrogen filled tyre for free!

 

[SLinKyjoe]

just to add a bit. nitrogen in the air we breath has moisutre in it. the nitrogen in the 230bar cylinders doesnt.

so if you fill you tyres with that, it will remain at a constant pressure irrespective of the humidty levels outside of the tyre, air in them will not. obvioulsy the tyre will increase pressure due to heat, but if you are using dry, or breathable air or nitrogen it will expand less as the moisture content is reduced. Dry air is filtered, and it still accepts an element of moisture but it is greatly reduced to normal compressed air.

bear in mind, motoGP riders and F1 drivers use tyres pressures to point something PSI. not like us who use whole psi.

ie, my tyres currently have 38psi in the rear and 35in the front. and F1 car will be 21.7psi. and they may reduce it to 21.4psi for the next set of laps. it is this difference that moisture can affect. not a whole PSI. Thats why its used in racing.

its also used in aircraft tyres, when the wheel goes through the air, pressure differentials of high altitude flying the difference is reduced thus meaning your tyres dont explode or deflate if you use nitrogen. bear in mind they are charged to 200psi so it makes a difference.

i filled mine with nitrogen as i have a nitrogen cylinder in my garage and you set the gauge at 2 bar and shove it on your valve. up goes the tyre. easier than using the compressor. Pure lazyness, thats all.

road use. nitrogen will make very little difference. and it cost £90 a year for the cylinder rent, and about £600 for the gauges etc. then you need £20 or so to fill the cylinder when its empty etc.

 

[Myros]

Ah , but that still doesn't get rid of the

Oxygen and moisture which was in there before you gave it a Nitrogen charge, unless you have the tyre mounted in a pure Nitrogen filled environment. Academic as you say with road tyres, which is probably why I won't be sticking any in mine.
I am impressed that you have your own Nitrogen supply though. Makes a change from showing people your etchings......

 

[davidsl500]

I am impressed that you have your own Nitrogen supply though. Makes a change from showing people your etchings......

oooerr, do you want to come home and check out my cylinder...


2 Bar only gives you 29-30 psi so how do you get the rest in Slinkmaster? ( blow it up to 2.5psi and let some out?)

 

[television]

a
I am impressed that you have your own Nitrogen supply though. Makes a change from showing people your etchings......

I spent a huge chunck of my life showing people my valves and tubes.

Malcolm

 

[mlc]

I spent a huge chunck of my life showing people my valves and tubes.

Malcolm

Yes and look what's happened to you, (from memory) 4 wives, heart bypass, poor eyesight, general ill health and you're only 29 years old

hard to beleive that a thread about someone been conned out of a tenner can drift like this, I love this forum!

Mark

 

[SLinKyjoe]

the harris guage on the cylinder is a reducer, it will reduce the 230bar down to anything between 0bar and 15bar. obviously at 0bar nothing comes out.

so you twiddle the twiddly bit till the gauge shows around 2bar and blow your tyres up. take about 30secs. you then need to check the tyre using a guage. i have a leccy one thats reasonable accurate. if you havent enough in you twiddle agin and blow again and check again.

if you have too much, you let a bit out.

As for Myros. yes you will still have air and that air will have moisture in it, but its reduced in content and therefore has less effect. IN F1 and Motogp, they blow up the tyres to max to check the tyre intergrity. then they let it all out again and start again. the theory is it pushes out at least some of the air that was in before.

my tyres have held the pressue since i did them in March. however, the air that was in them before never needed topping up either. so i am not sure about that idea of not checking them regular. seems like bad practice that does.

and if you put a bit more in them than you normally do. ie around 3-4psi, you will gain from a bit better fuel economy. dont know how much. but what you do is lose a small amount of road contact as you reduce the rolling resistance slightly, so unless you are really making an effort and pushing your tyres into the road, you may find, in cold and wetter conditions, that you lose traction a bit earlier.

Michelin eanergy tyres did the same and asked for people to pump that up quite hard to gain benefits. you also make the tyre harder which reduces your comfort. air or nitrogen will do the same as the pressure in the tyres is caused by the amount of it you put in and not what you put in.

 

[C220GJS]

Just to take this one step further, is it feasable to inflate tyres using hydrogen gas , therebye reducing unsprung weight ;as it's lighter than air as we all know. I know it's highly inflammable and got a lot of bad press from the R101 disaster, but we're driving about sitting on top of 16 gallons of highly explosive liquid anyway ,so why not?
Anybody got any rational or informed views on the subject or have I just made it plain to everyone just how insane I really am?
Geo.

 

[mlc]

Just to take this one step further, is it feasable to inflate tyres using hydrogen gas , therebye reducing unsprung weight ;as it's lighter than air as we all know. I know it's highly inflammable and got a lot of bad press from the R101 disaster, but we're driving about sitting on top of 16 gallons of highly explosive liquid anyway ,so why not?
Anybody got any rational or informed views on the subject or have I just made it plain to everyone just how insane I really am?
Geo.

Dear insane of Scotland

I am sure that someone will do the calculation, however I feel sure that the weight of the gas in a tyre will be very low in comparision to the weight of the wheel in total, so I think the difference caused by using a lighter gas will be insignificant.

I do however think that I have just stuck my neck out on this one

Mark