[Jeroen]

Originally Posted by ais

Again, I suggest you try these things personally, observe over time, and then provide us feedback from such experience.

When it comes to cars, there is very little I have not tried over time. However, I am not a great believer in extrapolating personal experiences. There is always a lot of bias in it, and one own's experience is in nearly always, just way, way too little to consider something factual.

If you have a personal experience on a technical matter and you can back it up with a solid engineering, physics and or chemical explanation, that makes it more worthwhile.

Of course, just my experience. Don't take too much notice. Obviously.

Originally Posted by Redex

Paying to fill your tyres with nitrogen is a SCAM !!!!!

Amen to that.

l

Originally Posted by Redex

Hi,

There is no evidence in the entire gamut of applied physics or chemistry that any particular gas is going to produce a tangible benefit to the dynamic performance of a tyre, or reduce the failures. Cornering, braking, steering, rolling resistance, ride quality - they’re all irrelevant to which gas you use.

Yep, that is my thinking and experience too.

Commercial airline tiers get filled with nitrogen. The FAA required so in the late 80s. This was due to several accidents (at least three I believe) with air-filled aircraft tires. That was also the decade where carbon brakes made their intro onto commercial airliners. And those babies run very very hot during braking. In fact, they don't work well, unless they are very hot! As compressed air is highly flammable, a rim with a carbon disc brake and a tyre filled with air is not a good combination.

Also, these aircraft tires run cold and hot enough for some of the small differences between air and nitrogen to become relevant. E.g. more consistent pressure.

Aircraft tyres go from ambient temperature to 300oC in the space of 1-2 seconds. But in cruise, they are at -40oC / -50oC. So a much broader range than in a car.


Now, those who have been reading my posts on TeamBHP for the last 11 years or so, know I am a very nerdy engineer, who likes to dabble a bit in science now and then.

What do engineers and scientists do, when the experiences (measured or otherwise) do not agree?

There are several options:

The theory could be wrong of course. Even some of Einstein's laws turned out not to be applicable to all situations. Happens to all great scientists.

We might require some new theories or fundamental insights. Although I am not that (yet) familiar with Quantum Mechanics, I dare say what we are facing here is a very simple physics/chemistry issue that does not require any new fundamental research into its behaviour! I could be wrong of course. Still, I am fairly optimistic on us the science here being dead on!!

The other possibility is that the experience as reported is incorrect. That could be for all sorts of reasons. Some are technical, some are not so technical.

Take your pick.

Jeroen

[ais]

Originally Posted by Jeroen

When it comes to cars, there is very little I have not tried over time.

Frankly, there is no point in debating this, research, conjectures and science, when science itself ultimately relies on proving theories through experiment. If one has tried both air and nitrogen and found no difference, fine. If nitrogen has not been tried thoroughly, nothing stops anyone from doing so. Here a simple experiment as suggested twice above will serve the purpose of convincing participants either way.

By the way, a similar doubt came to mind about RON 91, 95 and 97. So with the help of friend Karan of KS Motors, we dynoed my car with RON 91, then after 5-6 tank refills from empty to full with RON 97 dynoed it again- we found no difference in WHP!

Likewise, I suggest filling each side tyres of the car with air and nitrogen simultaneously and observe for a couple of months. If both behave identically, I'd be happy to switch back to air and save myself the bother of going to pumps having nitrogen! Cheers!

[Jeroen]

Originally Posted by ais

By the way, a similar doubt came to mind about RON 91, 95 and 97. So with the help of friend Karan of KS Motors, we dynoed my car with RON 91, then after 5-6 tank refills from empty to full with RON 97 dynoed it again- we found no difference in WHP!
!

We have a dedicated thread on high RON fuel, which I frequently visit. We have some members who will claim huge performance increases. You will find me on that thread pointing out that huge performance gains are simply not possible.

Depending on your engine, you might get a bit of gain, or none as you did, or actually get a slight degradation. It is all backed up by simple theory of how engines work and fuel chemistry. There are a million YouTube out there all coming to the same results. (Little or no gain, or getting slightly worse).

If you want to prove or disapprove a theory you need to show indisputable data. Which means it needs to go beyond “personal experience”. So you need to record the actual data of different sensors, the time, other relevant parameters etc.

We have threads on synthetic oil, high RON fuel and nitrogen filled tyres. They all have one thing in common. An abundant supply of personal experience, but also a complete lack of creditable data.

Jeroen

[Redex]

By the way, a similar doubt came to mind about RON 91, 95 and 97. So with the help of friend Karan of KS Motors, we dynoed my car with RON 91, then after 5-6 tank refills from empty to full with RON 97 dynoed it again- we found no difference in WHP!

Sadly the above statement demonstrates that you do not understand some of the basic fundamentals about physics and chemistry relating to motor vehicles. Neither do you seem to understand the terminology.
The "RON Number" has nothing to do with the energy content or power output of the fuel. The energy content is the same for all Ron numbers.
The RON number relates to a fuels "knock resistance" or detonation. Higher compression engines need a higher octane number fuel than lower compression engines otherwise knocking/detonation becomes a problem that can damage the engine and even reduce power output.
The Octane (RON) number has nothing to do with the heat or speed of combustion. Use the Octane (RON) fuel recommended by the car manufacturer. Lower Octane fuel may damage the engine, higher Octane fuel will not damage the engine but it is a waste of money as it will not make any more "WHP". You have already proved this point with your experimentation.
High performance cars use a higher Octane number so they can run at higher compression ratios and thus produce more power.
By the way, Ethanol has a higher Octane number than petrol. It won't make the car go any faster, in fact Ethanol blends have less energy than petrol and make less power.
Top fuel racing engine use Ethanol/Methanol (lower energy content) but run with compression ratios up to 16:1. Blended Ethanol fuel can have a RON value of 120 to 135 (still with a lower energy content than petrol). A typical car runs at between 8:1 and 10:1 compression ratio.
Higher compression means more fuel and air burnt at each cycle, that means more power. The engine needs a higher RON number fuel to avoid detonation. This allows for higher compression ratios and greater ignition advance producing more power.
I like your approach of practical testing, but with a little more knowledge and research you could save yourself a lot of effort. If you want more power increase the compression ratio or use AVGAS UL 91 (it has a higher energy content than Ethanol blended UL 91).
Personally, I would just go to a bigger engine for more power.

[ais]

Originally Posted by Jeroen

We have threads on synthetic oil, high RON fuel and nitrogen filled tyres. They all have one thing in common. An abundant supply of personal experience, but also a complete lack of creditable data.

When we see research and data on the internet, even then we check it practically to verify if it correct and applicable to us. In my experience and that of others here, it is evident that tryes hold constant pressure longer with nitrogen than air. Points on increased comfort may be subjective, but more than one person has mentioned them.

So for the 4th time, I'm requesting you to verify the "data" by using air and nitrogen simultaneously on each side of the car. In a couple of months, we can have your notational data on which tyres lose pressure earlier. The experiment is already controlled because there are 2 tyres with each type of fill. So that would be the most "credible data" for you, and us.

Kindly post observations on comfort etc. Data on tyre wear etc cannot be obtained as that process of degradation takes time and would be completely subjective in 1 or 2 cars.

As for RON affecting WHP, I simply wanted to check what my car does, and whether it is worth using a higher RON fuel or not. So I used my PERSONAL EXPERIENCE on how the car behaves while the fuel tank was being flushed of RON91 with repeated refills of RON 97. Then we dynoed the car GATHER CREDIBLE DATA rather than relying on the internet (including Team-BHP threads). Turns out no gain. Lost 1 WHP instead.

Here is the data from Dyno on 2.9.22. 91 RON.



Here is the data from 2.11.22. 97 RON.



Engine is tuned to 91 RON. In fact, this RON yield a higher torque by far much earlier- 80@1500RPM, 118 @2000RPM compared to 40 of RON 97.

The experience on engine knocking, stalling, fuel efficiency would all be subjective and personal, so deeming that as irrelevant and redundant.

Hope my point of view and practical approach is clearer now. I too use the internet, but only for preliminary research. Then as required, use that info as a backdrop and verify myself what works and what doesn't.

Hopefully I'll be posting a thread on all mods and upgrades on the Polo soon. You'll be surprised as to what lengths I've gone to to verify internet conjecture and information about suspensions with EXPERIENCE. After installing the B12, I've checked KW Street comfort with N1 Racing, Cobra springs and Sachs shockabs with Garfield and now going to try B8 with OEM springs with another Polo owner. Just to know what works best on Mumbai roads etc.

So it's about practical experience as well. I'm not measuring the compression and rebound data, and there may be a million videos on the internet about such suspensions, but ultimately readers who want a suspension upgrade on their Polo (or maybe other cars) will gain from my practial experiences!

We have digressed from this thread's topic, but hopefully the point of finding a balance between a practical approach as well as accumulation of data and research is delivered.

Hope this helps.

PS- Redex, I just read your post. Yes, I agree with you. I knew about what RON does and therefore tuned the car to RON 91 instead of OEM RON 95 as 91 is easily available. At that time, the tuner had explained these details. So had KS. I still wanted to check out for myself! Thanks for the details on Ethanol though- I am wiser now!

[Redex]

Hi,
not intending to be controversial or argumentative, just looking at the "real" benefits of nitrogen. I can only see 3.
1. Lower pressure loss (negated by using correct tyre pressure testing intervals),
2. The sudden release of compressed air during a vehicle fire "fanning" the flames with 21% oxygen as opposed to mostly inert nitrogen. Nitrogen which will contain at least 6% oxygen as explained earlier. Possibly the only justifiable reason for filling with nitrogen, although the rush of "nitrogen" will draw a large quantity of air along with it, reducing the benefit.
3. A weight saving of 6gms in total !!!!

It is already agreed and accepted that nitrogen looses pressure at a very slightly lower rate than air filled tyres, backed by scientific proof, common sense and fact, nitrogen "molecules" are 2.7% larger. However, the rate of loss from an air filled tyre is so minute that the benefit is insignificant/negligible. That's why we have been using air for nearly 140 years.
Sorry cannot do your practical test. I am "surprised" a serious petrol head would consider using a vehicle for at least 2 months without testing tyre pressures. I am not prepared to run my car for over 7,000 kms without checking the pressures. Far too dangerous.I check mine once a week, about 900 kms.
At the recommended pressure test interval advised by most manufacturers of 2 to 4 weeks the losses from air filled and nitrogen filled tyres will be virtually zero.
Unless the tyres are damaged or punctured, which is the WHOLE POINT of checking regularly.
As for the feel of the ride quality, purely subjective, not backed by real world scientific data. It's entirely up to you, if you "feel" any improvement carry on. I put that in the same category as people who experience dramatic improvements in noise, vibration, easier starting and more power after a simple routine oil change.

Regards Neil

[ais]

Originally Posted by Redex

Sorry cannot do your practical test. I am "surprised" a serious petrol head would consider using a vehicle for at least 2 months without testing tyre pressures. I am not prepared to run my car for over 7,000 kms without checking the pressures. Far too dangerous.I check mine once a week, about 900 kms.

I put that in the same category as people who experience dramatic improvements in noise, vibration, easier starting and more power after a simple routine oil change.

Where have I suggested that pressure not be checked? As a serious/hardcore petrol head, I've invested in a TPMS that tells me the pressure on demand. As mentioned, any drop below or rise above the preset limits will ring an alarm on the phone. How did you miss that bit when the picture of the readout is posted! Now Im shocked and saddened that someone who studies theory so much can miss that cruicial fact! I strongly suggest you invest in a TPMS. Sensairy is good.

On the contrary, you'll need to check the pressure regularly and note down-

1. Start of experiment pressure- say 30 PSI front, 29 PSI rear (left - air, right- nitrogen). (Since you don't have a TPMS or temperature reading- every time we check pressure with a guage, some air will be lost. You may want to start with a couple of PSIs more than usual to compensate for this).

2. Check after a long drive that you do regularly. Most likely the tyres with air will show a higher pressure

3. Check cold pressure after a week and repeat every week until the pressure drops a couple of PSIs below what you normally maintain.

We are looking to ascertain whether air filled tyre lose pressure faster than nitrogen.

While you're at it, you could check if there is any difference in how the left and right feel over rough surfaces.

Given how simple the above is, kindly consider. As it is, you're checking pressures every week.

And yes, an oil change from mineral to synthetic did result in a noticeably smoother engine for me in a Baleno. A change from dirty to new oil will obviosly result in a better performance. A simple car wash also results in a reduction in vibrations for a short while, probably because the bushes are lubricated with moisture.

So yes, some drivers like me 'feel' the car. I'd rather let the car give me info, not the internet or physics and chemistry books. That tyre noise I mentioned earlier was so minute, that a passenger with better hearing than mine could not hear it. The VW mechanic and the Michelin expert also could not notice the tyres outside edge blip until I showed them this against a laser pointer. I wonder what the theory behind this is- there is no deformity, no impact on the rear right while driving, no bald patch, no uneven wear. Tyres were 1 year old when bought, so might be a storage issue. Fact is, I noticed.

[Gansan]

Originally Posted by Gansan

I too got it done once during service long ago, but found during the monthly air filling that the drop in pressure was the same whether I filled air or nitrogen, and lost interest, convinced it is just a gimmick!

Having said this, I still do often fill nitrogen at my regular petrol pump during air checks, because the pump will be much less crowded due to the charge involved (Rs 10 per wheel). And also because they charge a fee, I feel the pump gauges will be better calibrated than regular air pump gauges.

I have read aircraft and F1 car tyres are filled with nitrogen for safety purpose, but they will be filled with really dry nitogen, which will not be possible in fuel stations or tyre shops.

[Redex]

As already agreed nitrogen does retain pressure longer than air. That's a fact and I have never disputed it. There is plenty of statistical and factual evidence to support the claim.
Providing that tyre pressures are checked every 2 to 4 weeks there is no benefit filling with nitrogen as the the ever so slightly lower leak rate will make no practical difference. At some point maybe 3 times a year for nitrogen and 4 times a year for air, the tyres will need inflating. I can get air at every garage. Can you get nitrogen at every garage or will you have to top up with air if the level is dangerously low.
The vast majority of people do not have TPMS or even a tyre pressure gauge, they don't know the pressure until they attach the tyre pump. What difference does it make if they have to add 1.2 psi instead of 1 psi. The safe range for tyre pressures is measured in single psi units in the real world.
The type of gas used does not matter in the slightest, read Boyles Law. The most important factor is correctly inflated tyres. That's what really affects handling, noise, quality of ride, braking, safety, rolling resistance , fuel economy etc etc etc.
Finally. YES nitrogen does leak at a very very slightly lower rate than air. In the real world for the average road user it will make no difference at all. I finish this discussion with a quote from Continental 3rd largest tyre producer in the world.

Continental Tyres statement on nitrogen :

So, now we come to the big question: is nitrogen right for your tyres? The fact of the matter is that inflating tyres with nitrogen is not necessary for typical everyday use on a passenger car. It might even be considered a frivolous waste of money.
To be clear, inflating tyres with nitrogen is not harmful. Moreover, the PSI stays steady in the long term. (Tyres filled with regular air lose pressure through permeation a little more quickly.)
But for the most part, nitrogen makes absolutely no difference when it comes to a loss of pressure caused by tyre punctures, tyre bead leaks, valve leaks or other mechanical leaks. There’s no discernible benefit over air-filled tyres, and that includes performance factors such as rolling resistance, fuel economy and tyre aging.

Enough said.

Regards Neil

[Jeroen]

Originally Posted by ais

So for the 4th time, I'm requesting you to verify the "data" by using air and nitrogen simultaneously on each side of the car. In a couple of months, we can have your notational data on which tyres lose pressure earlier. The experiment is already controlled because there are 2 tyres with each type of fill. So that would be the most "credible data" for you, and us.

There is absolutely no point in doing that. People and organisations, far more experience than me or you and with much more resources at their disposal have done these tests many times over. Comparing my own results against professionals and professional organisations is just laughable. Why do you think you know it better than those who have invested time and money in doing this sort of stuff for a living?

I have run very extensive engine and engine component test programs in the past professionally, across the wold. On my own I could not even get anywhere near. The fact that you suggest that your own experience or mine for that matter after conducting such test is relevant shows a lack of understanding one's own ability to conduct a proper unbiased, repeatable, accurate, unambiguous test.

Originally Posted by ais

Hopefully I'll be posting a thread on all mods and upgrades on the Polo soon. You'll be surprised as to what lengths I've gone to to verify internet conjecture and information about suspensions with EXPERIENCE.

Cant wait to see your thread. I love anything technical. Detailled work and explanations on cars I love. I might give it a try some time myself. Actually, I might have written the odd post about some of my spannering adventures.

Originally Posted by Redex

It is already agreed and accepted that nitrogen looses pressure at a very slightly lower rate than air filled tyres, backed by scientific proof, common sense and fact, nitrogen "molecules" are 2.7% larger. However, the rate of loss from an air filled tyre is so minute that the benefit is insignificant/negligible. That's why we have been using air for nearly 140 years.

Good summary Neil!

Originally Posted by Redex

As for the feel of the ride quality, purely subjective, not backed by real world scientific data. It's entirely up to you, if you "feel" any improvement carry on. I put that in the same category as people who experience dramatic improvements in noise, vibration, easier starting and more power after a simple routine oil change.

Originally Posted by ais

And yes, an oil change from mineral to synthetic did result in a noticeably smoother engine for me in a Baleno. A change from dirty to new oil will obviosly result in a better performance. A simple car wash also results in a reduction in vibrations for a short while, probably because the bushes are lubricated with moisture.
.

I have seen many posts about members reporting a noticeable difference after an oil change. Be it just a regular oil change, or from Mineral/semi to Synthetic.

If you experience a noticeably smoother engine, and less noise and vibration after any oil and filter change, the most likely reason is you had the oil/filter change performed too late. Your engine was really struggling with the old oil and filter. If you want to make claims as to synthetic oil makes an engine run smoother, you cant compare an old used oil, to a new synthetic oil.

You need to get at least two identical engines, with identical usage, mileage and perform an oil flush, install new filters and new oils. Now compare any difference between these identical engines, one running on mineral/semi and one running on synthetic. In a blind test you will not be able to tell which one is which!

Originally Posted by Gansan

I have read aircraft and F1 car tyres are filled with nitrogen for safety purpose, but they will be filled with really dry nitogen, which will not be possible in fuel stations or tyre shops.

Correct, I mentioned this before. If it is free (as it appears to be for some) or relatively cheap, it can not be highly pure nitrogen. It is just to expensive to manufacture. As I mentioned earlier, you should not use 100% pure nitrogen on tyres anyway. The ideal mixture is a bit lower.

Originally Posted by Redex

Enough said.

Yep!!

Jeroen

[Cresterk]

Originally Posted by SS80

Is there a real-world difference between the two air-filling options? I mean a major portion of our normal air is nitrogen. I also highly doubt if a petrol bunk machine can extract pure nitrogen from the air. May be possible in a lab, but not at this scale and place.

From what I recall, the point is to remove as much oxygen and water vapour / moisture from inside the tyre as possible. This is done by machines that have a purge option by sucking out the air and refilling the tyres with nitrogen multiple times simultaneously. You can recognize these machines by the 'N2P' written on them.


I got mine done at an HP pump for free.

The average tyre shop/garage where they just deflate it and then fill it up with nitrogen from a machine and collect 300rs from you is just a scam.

After doing this, the tyre doesn't heat up as much during long trips. If you have a car with a tyre pressure monitor, you can see the pressure increasing as you drive from air inside the tyre heating up. Mine generally goes from 34 psi when cold to 37/38 psi when driving fast on hot sunny days.

The slight pressure drop from air leaking out through the side walls every month is also much lesser than it used to be.

[ais]

I recently had punctures on my Polo's rear left and later front left tyres. I got them repaired at Saifees, who don't have nitrogen. So until I got air replaced with nitrogen after a couple of days, I was driving with nitrogen in the left and air in the right tyres.

I maintain pressure to the exact decimal, one of the reasons being that any variation of .3psi or more, and increasing over time, indicates a puncture early.

The difference in change of pressure between air and nitrogen as the tyres warm up during driving is stark, as much as 2 psi. For me it is a lot, as even a .5psi difference makes a difference to the way the car feels during spirited driving (refer to the thread on this Polo for suspension mods).

So the contentions made by me earlier in this thread are validated. While in regular cars and normal grocery shop trips it may not matter, there are good reason why performance cars use nitrogen.

[jomyboy]

Since I have got alloy wheels and live in Mumbai, nitrogen actually does make some sense. Unlike regular air, it doesn’t trap moisture, so there’s less chance of internal corrosion—which is a solid win in salty, humid conditions.

And if I ever leave my car parked for a long time? Well, nitrogen helps that extra 0.0001% in keeping things from rusting inside. Not a game-changer, but hey, every little bit counts!