R36 - Nitrogen

[Rocket36]

That's one reason plans use it. The other significant reason is the extremes of cold and hot planes landing gear experience. Nitrogen isn't as affected by extreme changes of temerature as much as air.

People can all think what they want and do what they want though. But at $5 a tyre every 6 months (which is nothing really), it's all a bit of a moot point.

I've explained the reasons why Nitrogen is better than air for me so I'm not going to flog a dead horse just because some people can't accept that, or don't understand that.

[Lance B]

The interesting thing here about all this discussion is that there has not been one shred of evidence (that I could find) shown by either side of the argument as to any actual A/B tests. It has all been pure speculation and anecdotal evidence. I can see the possible reasons why nitrogen may work and I did try it many years ago, but my trial was a little inconclusive and so I thought that the cost and inconvenience was not worth the effort. I did notice two things, though:
1) The pressure fluctuation from cold to hot seemed less than with normal compressed air.
2) The tyres didn't seem to lose as much pressure over time, but I was trialing it from winter to summer and this may account for the perceived non-pressure-loss, ie the tyres may have permeated air through the tyre but as the weather was getting warmer the pressure drop was possibly negated.

[Timbo]

there has not been one shred of evidence (that I could find) shown by either side of the argument as to any actual A/B tests.

Good point. The reason is because it's hard to produce any noticeable effect in road use. If there were significant benefits (eg, fuel economy), you'd bet the likes of Toyota would fill Prius tyres with N2 at the factory.

It's just a little more cash for the tyre sellers, folks. By all means, donate if you wish to

[Maverick]

The interesting thing here about all this discussion is that there has not been one shred of evidence (that I could find) shown by either side of the argument as to any actual A/B tests. It has all been pure speculation and anecdotal evidence. I can see the possible reasons why nitrogen may work and I did try it many years ago, but my trial was a little inconclusive and so I thought that the cost and inconvenience was not worth the effort.

One of the biggest issues I have with Nitrogen is that it lulls people into a false sense of security and stops them from checking/topping up tyres at the servo. Even if they check with a tyre gauge they may delay topping up tyres because of the cost. Regular checking of tyre pressures unless you have an in wheel TPMS is critical for safety (and even with the TPMS you should still do visual checks).

I did notice two things, though:
1) The pressure fluctuation from cold to hot seemed less than with normal compressed air.

This is easily proven to be false, there's info on this over the last few pages.

2) The tyres didn't seem to lose as much pressure over time, but I was trialing it from winter to summer and this may account for the perceived non-pressure-loss, ie the tyres may have permeated air through the tyre but as the weather was getting warmer the pressure drop was possibly negated.

This one is true but only very slightly, there have been a number of long term tests done in the US and they found that nitrogen is not worth it.

Tires - Nitrogen air loss study
Nitrogen in tires - Q&A

"The test started on September 20, 2006 and the final measurements were taken on September 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely. No evaluation was done to assess the aging claim."

But many people swear by products that do nothing or spend big dollars to get minimal gains on different products so each to their own however I do have issues with the tyre places pushing nitrogen as some magic elixir that many drivers will see as a way to never have to check the tyre pressures with the resulting problems (faster wear, blowouts etc).

[R36Driver888]

One of the biggest issues I have with Nitrogen is that it lulls people into a false sense of security and stops them from checking/topping up tyres at the servo. Even if they check with a tyre gauge they may delay topping up tyres because of the cost. Regular checking of tyre pressures unless you have an in wheel TPMS is critical for safety (and even with the TPMS you should still do visual checks).



This is easily proven to be false, there's info on this over the last few pages.



This one is true but only very slightly, there have been a number of long term tests done in the US and they found that nitrogen is not worth it.

Tires - Nitrogen air loss study
Nitrogen in tires - Q&A

"The test started on September 20, 2006 and the final measurements were taken on September 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely. No evaluation was done to assess the aging claim."

But many people swear by products that do nothing or spend big dollars to get minimal gains on different products so each to their own however I do have issues with the tyre places pushing nitrogen as some magic elixir that many drivers will see as a way to never have to check the tyre pressures with the resulting problems (faster wear, blowouts etc).

Wow I am blown away by everyones responses some good some bad at the end of the day I think all comments where useful....

Do nitrogen - don't do nitrogen it doesn't matter so long as everyone is having fun driving their VW... p.s. R36 loves to eat the new MPS...

[V6Passat]

Sorry Maverick, but while Nitrogen has a lower molecular weight, 28 Vs O2 with 32, the molecule size is actually larger thus it does not permeate thru the rubber walls as fast as O2.

And the science behind it...Link

ok....my brain just went into melt dowm!!

[Lance B]

One of the biggest issues I have with Nitrogen is that it lulls people into a false sense of security and stops them from checking/topping up tyres at the servo. Even if they check with a tyre gauge they may delay topping up tyres because of the cost. Regular checking of tyre pressures unless you have an in wheel TPMS is critical for safety (and even with the TPMS you should still do visual checks).

Most who use nitrogen are probably more fanatical about their cars and would check regularly, like I do. I am quite fanatical about correct tyre pressures when I was using it.

This is easily proven to be false, there's info on this over the last few pages.

Actually, this has not been proven to be false, just that there is some evidence on both sides of the argument. My evidence suggests that there is less pressure fluctuation between hot and cold pressures.

This one is true but only very slightly, there have been a number of long term tests done in the US and they found that nitrogen is not worth it.

And I am sure just as many that show that it is.

Tires - Nitrogen air loss study
Nitrogen in tires - Q&A

"The test started on September 20, 2006 and the final measurements were taken on September 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely. No evaluation was done to assess the aging claim."

But many people swear by products that do nothing or spend big dollars to get minimal gains on different products so each to their own however I do have issues with the tyre places pushing nitrogen as some magic elixir that many drivers will see as a way to never have to check the tyre pressures with the resulting problems (faster wear, blowouts etc).

[gldgti]

wow, what a discussion.

i thought i'd just add this little bublle of thought to the mix - we're all talking about nitrogen an comparing it to air right?..... thing is, nitrogen isnt the variable here, its the AIR. the atmosphere is a mix of many gasses, and i'd bet my last couple of bucks that one one making the biggest difference to tyre pressures (and that causes the fluctuations seen) is good old water vapour. i'd even theorise that the drier the air you use, the less fluctuations you'll have.....

[Maverick]

Actually, this has not been proven to be false, just that there is some evidence on both sides of the argument. My evidence suggests that there is less pressure fluctuation between hot and cold pressures.

This has been proven to be false, I posted the science behind why earlier and if dry compressed air is used the "benefit" of nitrogen tyres weighing 2.5 grams less per tyre disappears. The only slight difference can come about from there being some additional moisture in the tyre if the tyre is not filled with dry compressed air but on the flipside seeing as the tyre is not removed, cleaned out and filled 100% with nitrogen I fail to see how nitrogen works any better

"N2, being a lighter molecule, diffuses out faster. Having less weight, it also improves handling as there is less rotating mass - but not by much. If we assume a tyre has a volume of about 24 litres and is at 2.5 atmospheres pressure, then the weight of dry air in it will be 72.5 grams. (with air at 80% relative hummidity, it will be about 71 g). Fill it with N2, and it will weigh 70 grams. So you save a whopping 2.5 grams out of maybe a total tyre weight of 10 kg. Olympic cyclists fill their tyres with He to save a few grams - but then a few grams means 0.01 second which might be the difference between a medal or not.

A gram or so of ice in the tyre may cause issues, providing you drive around corners at 300 km an hour within a few seconds of starting the car and before it has melted and evaporated.

As the tyre warms up, the air or nitrogen will expand. If the tyre is at 20 C and then warms up to 40 C, then the air or nitrogen will expand by 1-((273+(40-20))/273) = 0.07 or 7%. If the tyre is at 35 psi at 20 C, it will increase to 37.5 psi at 40 C. Filling with different gases will make no difference as they all expand the same amount if raised by the same amount. If anything, using a denser gas such as S8F will take longer to heat up due to the higher specific heat (amount of heat required) to take it from 20 to 40 C (or whatever) but then will stay warmer longer."

And I am sure just as many that show that it is.

You have consumer organisations, government organisations, motoring organisations and various magazines and so forth all debunking Nitrogen.

You have tyre stores, nitrogen sellers and people who also promote slick 50 pushing Nitrogen with wild claims.

Each to their own but I'll stick with science and back the former group

[Maverick]

wow, what a discussion.

i thought i'd just add this little bublle of thought to the mix - we're all talking about nitrogen an comparing it to air right?..... thing is, nitrogen isnt the variable here, its the AIR. the atmosphere is a mix of many gasses, and i'd bet my last couple of bucks that one one making the biggest difference to tyre pressures (and that causes the fluctuations seen) is good old water vapour. i'd even theorise that the drier the air you use, the less fluctuations you'll have.....

Spot on, covered somewhere on page 2 and I think 1 and maybe 3 as well.