was adding nitrogen yesterday

 

Well the temps have dipped so I felt I need about 2 more psi again, so I was at Costco.

While I was doing my car, I saw something interesting.

A man got out actually on the wrong side of the pump but the hoses do reach, and he was holding a tissue, so that his fingers did not come in contact with the valve cap. Was he avoiding germs or covid or what??!

Enquiring minds want to know what you think

Dirt

As a long-time driver of German cars, I'm used to the wheels, wheel covers, and valve covers on my cars having lots of nasty brake pad dust. So when I do my monthly pressure check and top up (in my own garage) I wear nitrile gloves to do the tire pressure round and the oil level check. Then I wash the gloves at the garage slop sink by just washing my hands with the gloves still on them.

--
personal GPS user since 1992

Do you folks with lower

Do you folks with lower profile tires find air pressures to be more sensitive to temp changes?

I currently have 245/40/18's on the car. Previous car was 235/55/17. Seemed the latter kept air pressure better when temps changed. Probably makes sense given there was more physical air volume present¿?

good answer

archae86 wrote:

As a long-time driver of German cars, I'm used to the wheels, wheel covers, and valve covers on my cars having lots of nasty brake pad dust. So when I do my monthly pressure check and top up (in my own garage) I wear nitrile gloves to do the tire pressure round and the oil level check. Then I wash the gloves at the garage slop sink by just washing my hands with the gloves still on them.

Yes my BMW's fronts are always blackened, due to the semi metallic pads. Some switch to ceramic for dusting and noise, but I won't. I actually use OE although I know it makes total sense to use OEM like Pagid or Jurid.

The dude's car was a Camry though lol

actually not at all

zx1100e1 wrote:

Do you folks with lower profile tires find air pressures to be more sensitive to temp changes?

I currently have 245/40/18's on the car. Previous car was 235/55/17. Seemed the latter kept air pressure better when temps changed. Probably makes sense given there was more physical air volume present¿?

Really the rule is 1 psi per 10F either way, size of tires doesn't matter as it's PSI.

My garage queen has 255/35-18 on the back, which at the time was low profile. I suppose 35's are still low, cuz I think Corvettes have 30's in the rear.

I always feel a bit depressed putting on snows, because on both cars, the tires are taller and skinnier. I know winter tires are better, but on my wife's we just leave the A/S with her AWD and it's been ok.

We've had lots of temp

We've had lots of temp swings lately, so I suppose its to be expected. All the tires are losing air equally, so it's not a puncture.

Car is new (2 months old) so can't be bead rust.

interesting

Yes, in some sense it's annoying if it's 70F one day, 40F the next evening. I'd rather be 3 PSI over (although if it's going to be for too long, better to let some out), than 3 PSI under. So with nitrogen I'm glad Costco has the DIY pumps. And it's only 1/3 of our cars that has that.

Another case: At the time my used car was about 13 years old and one tire was losing air, and doing the soapy water thing, I saw it was from the bead. I decided to try something that fixes everything. I let all the air out, and tried to pry the tire away from the rim, and then inserted duct tape. Wouldn't you know, I found one thing that duct tape can't fix?!

So taking it to a local tire shop, they removed the tire and to the surprise of the tech and myself, there was not the corrosion that we had expected to see (I looked online and envisioned needed wire brushes etc). They did apply a sealant and then remounted/balanced and used a new valve stem and it was good. I hope there's not a mess inside the rim but I suppose even if there is, that's Costco's worry as I plan on buying tires there next year...

p.s. my wife's GM is the only car that tells the PSI on the dash, and my Toyota product does not even have sensors (I guess it goes by tire rotation/ABS).

The GM can be wonky. Sometimes I look and it could say 37/36/37/35, and the 35 drives me nuts. Then maybe 10 min later, 38/38/38/38. Granted, the sensors are 10 years old, but it's been doing that since new. On my BMW I replaced them when I got new tires, but that was probably a waste....can't remember how much they cost I got them online. GM, however, I think the sensors are relatively inexpensive....

p.p.s. also amazing when the car was new, the reset tool was about $90. I bought one when they were $20. Now they are $9! This is the tool to reset GM TPMS sensors, like when tires are rotated...again I think 2010 and older can be done manually, 2011+ needs the tool.....of course we got the 2011

There is a term for all this

johnnatash4 wrote:

Yes, in some sense it's annoying if it's 70F one day, 40F the next evening. I'd rather be 3 PSI over (although if it's going to be for too long, better to let some out), than 3 PSI under. So with nitrogen I'm glad Costco has the DIY pumps. And it's only 1/3 of our cars that has that.

Another case: At the time my used car was about 13 years old and one tire was losing air, and doing the soapy water thing, I saw it was from the bead. I decided to try something that fixes everything. I let all the air out, and tried to pry the tire away from the rim, and then inserted duct tape. Wouldn't you know, I found one thing that duct tape can't fix?!

So taking it to a local tire shop, they removed the tire and to the surprise of the tech and myself, there was not the corrosion that we had expected to see (I looked online and envisioned needed wire brushes etc). They did apply a sealant and then remounted/balanced and used a new valve stem and it was good. I hope there's not a mess inside the rim but I suppose even if there is, that's Costco's worry as I plan on buying tires there next year...

p.s. my wife's GM is the only car that tells the PSI on the dash, and my Toyota product does not even have sensors (I guess it goes by tire rotation/ABS).

The GM can be wonky. Sometimes I look and it could say 37/36/37/35, and the 35 drives me nuts. Then maybe 10 min later, 38/38/38/38. Granted, the sensors are 10 years old, but it's been doing that since new. On my BMW I replaced them when I got new tires, but that was probably a waste....can't remember how much they cost I got them online. GM, however, I think the sensors are relatively inexpensive....

p.p.s. also amazing when the car was new, the reset tool was about $90. I bought one when they were $20. Now they are $9! This is the tool to reset GM TPMS sensors, like when tires are rotated...again I think 2010 and older can be done manually, 2011+ needs the tool.....of course we got the 2011

It's "analysis paralysis"

--
John from PA

I'm

John from PA wrote:
johnnatash4 wrote:

Yes, in some sense it's annoying if it's 70F one day, 40F the next evening. I'd rather be 3 PSI over (although if it's going to be for too long, better to let some out), than 3 PSI under. So with nitrogen I'm glad Costco has the DIY pumps. And it's only 1/3 of our cars that has that.

Another case: At the time my used car was about 13 years old and one tire was losing air, and doing the soapy water thing, I saw it was from the bead. I decided to try something that fixes everything. I let all the air out, and tried to pry the tire away from the rim, and then inserted duct tape. Wouldn't you know, I found one thing that duct tape can't fix?!

So taking it to a local tire shop, they removed the tire and to the surprise of the tech and myself, there was not the corrosion that we had expected to see (I looked online and envisioned needed wire brushes etc). They did apply a sealant and then remounted/balanced and used a new valve stem and it was good. I hope there's not a mess inside the rim but I suppose even if there is, that's Costco's worry as I plan on buying tires there next year...

p.s. my wife's GM is the only car that tells the PSI on the dash, and my Toyota product does not even have sensors (I guess it goes by tire rotation/ABS).

The GM can be wonky. Sometimes I look and it could say 37/36/37/35, and the 35 drives me nuts. Then maybe 10 min later, 38/38/38/38. Granted, the sensors are 10 years old, but it's been doing that since new. On my BMW I replaced them when I got new tires, but that was probably a waste....can't remember how much they cost I got them online. GM, however, I think the sensors are relatively inexpensive....

p.p.s. also amazing when the car was new, the reset tool was about $90. I bought one when they were $20. Now they are $9! This is the tool to reset GM TPMS sensors, like when tires are rotated...again I think 2010 and older can be done manually, 2011+ needs the tool.....of course we got the 2011

It's "analysis paralysis"

surprised my wife's trip computer didn't tell us to buy Apple stock in 2009. How about when a car's dash says "Range."

I always wondered how the car can predict the future--i.e. you have 5 gallons left. How does it know if you're going to be stuck in bumper to bumper traffic, or going to drive on the highway steadily at 62 mph? The range could be 50 miles, or it could be 100 miles. Wouldn't it be best to take a screwdriver and poke out the display so you don't see it? lol

p.s. everyone knows how to calculate avg mph. I drove 60 miles in one hour, what was my average velocity?

How many people know how to calculate instantaneous velocity? In my day, anyone who graduated HS. Today? not sure lol

This will blow your mind

And to make things worse, all your air pressure gauges all suck.

I had a handful of pressure gauges, and the indicated pressure of all of them varied some 15-20 psi, and the readings were all over the place. There was no common reading they were heading towards, with just a couple outliers. It was complete chaos.

There was, and is, no way I was getting near true accurate pressures. So now I just set the pressures to be balanced and known, and do not worry at all over slight (a couple psi) variances since the pressure gauges clearly can't do it.

--
GPSMAP64s, iPhone 12, Yaesu VX-8R w/GPS.

you're right

diesel wrote:

And to make things worse, all your air pressure gauges all suck.

I had a handful of pressure gauges, and the indicated pressure of all of them varied some 15-20 psi, and the readings were all over the place. There was no common reading they were heading towards, with just a couple outliers. It was complete chaos.

There was, and is, no way I was getting near true accurate pressures. So now I just set the pressures to be balanced and known, and do not worry at all over slight (a couple psi) variances since the pressure gauges clearly can't do it.

I don't have a 1/4", but I have 3/8" and 1/2" torque wrenches. They have calibration certificates. I think of that as being like sourdough bread. The actual reading is meaningless, unless the instrument that created that certificate has a reference to something that is known to be true.

Since I don't work in a shop, I have never had them recalibrated.

Back in the day, I was fortunate, and bought a brand new Porsche. It came with a tire pressure gauge that I have to this day. Analog, made by VDO in Germany. I was using it in the mid 2000s on my BMW. It annoyed me so much that I would set my tire pressure, and the BMW dealership would inflate the tires another 6 psi, wth are they doing!!!!! So I bought 2 different kinds of gauges with LCD readouts, and they were within 1 psi of one another (one rounds to 0.5, the other 0.1, 0.1 is unnecessary and likely off), and if accurate, the BMW dealership was inflating to the correct psi!!!!

I guess that VDO dial gauge would be vintage and worth something to a Porschefile who likely has it missing if they bought the car used.

This has doubled in price (what hasn't) but what I have today, simple and seemingly close enough....

https://www.amazon.com/Accutire-MS-4021R-Digital-Pressure-Ga...

Had you bought Apple stock on August 24th 2011

I'm surprised my wife's trip computer didn't tell us to buy Apple stock in 2009.[/quote]

On the 10th anniversary of Tim Cook taking over Apple, just a month ago, it was publicized that had you invested $1000 in Apple stock on that day (August 24th 2011), it would be worth $12.4 million today.

--
John from PA

not sure about that

I'm not clear how 1k becomes 12 mil.

I can see 1k becoming 11k from 8/24/11 to today.

And if Jan 2009, 1k becomes 53k.

I would have to applaud Apple's publicist for saying 1k is 12 mil in 10 years! lol

I tried one more thing...if a person invested in Apple on the open market the day it was available, $1000 is 1.153 mil today.

Who knows where the 12 mil came from.

I'll never even know 53x is my point. Some of my stocks have multiplied 10x, over a long period of time. That's not going to really do much. I was always one of those people oh, it is 3X what I paid now, I better sell before I lose it all. Dumb. My parents taught me not to be greedy. But who gets ahead in this life? lol

Inquiring Minds Want to Know

johnnatash4 wrote:

surprised my wife's trip computer didn't tell us to buy Apple stock in 2009. How about when a car's dash says "Range."

I always wondered how the car can predict the future--i.e. you have 5 gallons left. How does it know if you're going to be stuck in bumper to bumper traffic, or going to drive on the highway steadily at 62 mph? The range could be 50 miles, or it could be 100 miles. Wouldn't it be best to take a screwdriver and poke out the display so you don't see it? lol

p.s. everyone knows how to calculate avg mph. I drove 60 miles in one hour, what was my average velocity?

How many people know how to calculate instantaneous velocity? In my day, anyone who graduated HS. Today? not sure lol

This post has nothing to do with the subject at hand but I was struck by the johnnatash4's term, "instantaneous velocity" as I had never heard of it before. I took both Calculus and General Physics classes in college but I don't remember covering this application but that was a long time ago (early to mid-1960s). My curiosity on the subject took me to Khan Academy for a clear explanation of "instantaneous velocity".

https://www.khanacademy.org/science/physics/one-dimensional-...

@johnnatash4 My stinger has

@johnnatash4

My stinger has direct tpms. I use a digital gauge (supposedly accurate to .1 psi) to set all the tires to the respective pressures (front is lower than rear). Get in and drive. Once the sensors sync with the car they all read different numbers. I rely on the gauge not the tpms sensors. IMO they're good for telling you you're REALLY low or high on air.

Accuracy vs. Precision

Every once in a while is is worthwhile to review:

https://en.wikipedia.org/wiki/Accuracy_and_precision

"accuracy of a measurement system is the degree of closeness of measurements of a quantity to that quantity's true value"

"precision of a measurement system, related to reproducibility and repeatability, is the degree to which repeated measurements under unchanged conditions show the same results"

Fair point. Had to hunt

Fair point. Had to hunt down the owners manual. Accuracy - ±1 psi. Lol!

Question is, how does that accuracy vary. Each time you attach/disconnect the chuck. Each time it's power cycled. I'd be ok with the numbers being off so long as they're consistent between all 4 tires. That is it shows 35 psi, but actual is 34, but it's the same error on all wheels.

The answer to your question is very dependent on the actual devi

zx1100e1 wrote:

Question is, how does that accuracy vary. Each time you attach/disconnect the chuck. Each time it's power cycled. I'd be ok with the numbers being off so long as they're consistent between all 4 tires. That is it shows 35 psi, but actual is 34, but it's the same error on all wheels.

The answer to your question is very dependent on the actual device. You can find pressure gages online, reported to be what Nascar Teams use, at $450.

More than you wanted to know about pressure gage accuracy can be found at https://www.apgsensors.com/about-us/blog/the-secret-sauce-of...

--
John from PA

Preventing Dirty Hands

He probably did not want to get his hand dirty.

What does nitrogen offer

What does nitrogen offer that air (~80% nitrogen) does not offer?

Not much...

telecomdigest2 wrote:

What does nitrogen offer that air (~80% nitrogen) does not offer?

In a previous thread (http://www.poi-factory.com/node/51788) I stated "To the typical car owner there is no benefit to nitrogen and absolutely no need to pay extra for it!. The hoopla came out because long haul trucks and especially commercial aircraft can in theory benefit. For aircraft, it is very critical to have dry inert gas in the tires. At 35,000 feet the typical temperature outside aircraft is -60 deg F so as you can imagine any moisture in the air would freeze. For long haul trucks, the theory is that a nitrogen molecule is larger than an oxygen molecule and therefor the leakage through the sidewall is slower. But for passenger car tires the sidewall leakage is slow. Better to just check tie pressures quarterly (or sooner). And if you have a donut spare check it as well; they are often forgotten."

--
John from PA

Zero

telecomdigest2 wrote:

What does nitrogen offer that air (~80% nitrogen) does not offer?

Nitrogen is supposedly dry, meaning no H2O. The H2O content of air is what largely changes in specific volume as a function of temperature and alters the indicated tire pressure. Dry nitrogen will reduce the changes in indicated tire pressures with temperature, which is also why race cars use dry nitrogen.

--
GPSMAP64s, iPhone 12, Yaesu VX-8R w/GPS.

I know

To reiterate, Costco is free. They don't charge more for nitrogen. Anybody can walk up to the pumps and use them, although the sign says for members only.

Costco does not say you cannot add air to tires purchased there.

Thirdly, they do state, that over time, Nitrogen retains tire pressure better. Over time.

The reason I started the thread was that I noticed there were self serve pumps, and looks like they've been there a year already. It's a pita to have the persons in the shop do it, and much easier to DIY.

My own observation? The nitrogen responds same as air, 1 PSI per 10F, which I didn't expect when we first got nitrogen years ago.

Maybe someone can fill a can with what they are dispensing, and analyze if it's really air or anything else? In this whole world there are people who have the time and means, and it would be interesting to know. Or, maybe someone worked on the installation of these pumps and knows if there is really a tank of nitrogen that gets filled, or it simply dispenses air.

Also, if anyone really knows why a tissue was used to remove valve caps on a Camry, is it Covid related?

p.s. I believe the only claim or statement Costco makes is that pressure retention is better OVER TIME. So this, if true, helps people who do not check often.

78%

Air is 78% nitrogen. Compressed air limits the amount of water vapor, but there is still some water vapor in compressed air. Changing to 100% nitrogen offers little benefit to street usage. In a car racing situation, the consistency of 100% nitrogen allows for better fine tuning and predictability in tire pressure where fractional pressure matters.

Nitrogen filled tires will still respond to changes in ambient temperature similar to using air in tires. Thermodynamics demands no less. Gradual minor loss of pressure over time when comparing 78% nitrogen to 100% nitrogen, again would be very similar and for a street car.

I drive a very high performance sports car and tire pressure is very important to me. I check my tire pressures on each use and have a compressor right next to the car for fine tuning. I keep my pressures within 1 PSI cold of what is optimal for my car. I don't see any benefit to switching to 100% Nitrogen.

--
___________________ Garmin 2455, 855, Oregon 550t

funny

If people still did what my grandfather did. Whatever the car says the psi should be, add 2-4 to it, because the mfg wants a soft ride lol

I did find that as late as 2007, I was doing something that my grandfather did, and that was to not move a tire from one side to another, i.e. reverse the direction on non directional tires.

Back then I was talking about the RE070A run flats and asked the forum how do you mark the tires? paint marker, crayon or chalk?

Someone said why? The tires are not directional and your rears are wider than the fronts. Then through google which makes us all experts in everything, I found that not moving from one side to the other was something from the 70's and bias ply tires...

I liken that to when I see someone driving with hands at 10 and 2 o'clock. That practice was discouraged starting around 1991, imagine how long ago, and people still do it? I saw my 7 y.o. get in the driver's seat of a bus. His hands were below 9 and below 3. Imagine that young and they already know.

Nitrogen is a consumer scam

Nitrogen is an out-and-out scam. Aside from their use in aircraft tires where a tire can go from -40 to 350 degrees in an instant on landing and then have to get tucked up into a very tight wheel well space on a balked landing, nitrogen provides ZERO benefits. It is what we call Junk Science and there is no science that supports it.

Anyone who tries to sell nitrogen by saying the molecules are bigger has: 1) never looked at a table of elements (Oxygen and nitrogen are side-by-side, so the difference in size in infinitely small); and 2) have a poor understanding of the size of molecules. To think nitrogen is less prone to leak out tiny openings is ridiculous. The period at the end of this sentence has an area that could contain 100 million molecules. (Okay ... maybe only 99.5 million nitrogen molecules, because of course they are so much "larger.")

By the way, in an article on the police vehicles issue for a national police magazine, they used a scientific nitrogen content reader to test tires supposedly filled with nitrogen. Out of 30 dealerships and garages, only four of them had nitrogen content over 85% and only one had nitrogen content over 90%. 25 of them had nitrogen content of 77% to 79% (meaning, plain old air.)

While it can't hurt, even if it's free there is always a cost hidden somewhere. Plus, the reason I immediately took off those lime green valve caps when I recently bought a used car for my daughter is simple. This was the quote from that magazine article from a garage owner:
"Nitrogen? Hell, yeah. We love it. When we see those lime green valve caps pull up, we know we can sell that sucker ANYTHING."

Good info at Tire Rack

johnnatash4 wrote:

To reiterate, Costco is free. They don't charge more for nitrogen. Anybody can walk up to the pumps and use them, although the sign says for members only.

Costco does not say you cannot add air to tires purchased there.

Thirdly, they do state, that over time, Nitrogen retains tire pressure better. Over time.

The reason I started the thread was that I noticed there were self serve pumps, and looks like they've been there a year already. It's a pita to have the persons in the shop do it, and much easier to DIY.

My own observation? The nitrogen responds same as air, 1 PSI per 10F, which I didn't expect when we first got nitrogen years ago.

Maybe someone can fill a can with what they are dispensing, and analyze if it's really air or anything else? In this whole world there are people who have the time and means, and it would be interesting to know. Or, maybe someone worked on the installation of these pumps and knows if there is really a tank of nitrogen that gets filled, or it simply dispenses air.

Also, if anyone really knows why a tissue was used to remove valve caps on a Camry, is it Covid related?

p.s. I believe the only claim or statement Costco makes is that pressure retention is better OVER TIME. So this, if true, helps people who do not check often.

Tire Rack has a good article titled CLEARING THE AIR ABOUT NITROGEN TIRE INFLATION at https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=....

Being a mechanical engineer and working with thermodynamics for 50+ years the article is quite good and can dispel many of the myths about nitrogen. One sentence is worthy of some clarification and that is the statement reading "Nitrogen reduces the loss of tire pressure due to permeation through rubber over time by about 1/3." What is meant is that if with normal atmosphere fill your leakage over time is 6#, then with nitrogen you could anticipate 4# or 1/3 less.

As far as what shops are doing, and in response to the question "Or, maybe someone worked on the installation of these pumps and knows if there is really a tank of nitrogen that gets filled, or it simply dispenses air", the content at the link seems to describe the system that some stations may have when it is said

Quote:

Several service equipment manufacturers have developed small, on-site nitrogen generator systems that use the selective permeation principle to separate oxygen and moisture from the shop's compressed air lines to capture nitrogen. The key component is a membrane that separates the gasses. Each module contains hollow fibers that allow the oxygen and water vapor to be selectively removed, resulting in a source of nearly pure nitrogen that is kept in a separate storage tank until it is used to inflate tires.

The nitrogen generator, storage tank and filling system aren't free and the dealer is entitled to some return on his investment. It's time-consuming for a technician to bleed air from the tires (sometimes requiring several purges during the initial inflation) to achieve the desired nitrogen purity, however some of the latest equipment automatically goes through several purge cycles without requiring the technician's participation.

To sum things up, some of us old timers probably remember Tom & Ray of Car Talk. Many people would call in and ask about the benefit of certain procedures. I loved their reply when it was stated that the procedure provided a boat payment and not much more.

--
John from PA

Nitrogen or not

telecomdigest2 wrote:

What does nitrogen offer that air (~80% nitrogen) does not offer?

If you check your tire pressures regularly, nitrogen offers little benefit. Now, if you are the type that checks air pressures every year or two whether it needs it or not, then nitrogen is a huge benefit. Nitrogen will not leach out as fast as air and hold it's fill pressure longer (uniform larger molecules). There are a few ancillary benefits as well, but holding the pressure longer is it's main benefit. And yes, like every gas, pressure is temp. dependent, but don't chase it, twice a year (winter/summer)is sufficient, but check it at least on a monthly basis unless you are nitrogen filled, seasonal in that case.

Boyle's Law

I buy my tires from Costco for my two vehicles. I have an air compressor at home that I use to fill my tires about four times a year or sooner if the tires appear low.

Over a period of years, I'm not sure how much of the original nitrogen fill is left from the initial fill as the N2 concentration is diluted every time I refill my tires with my tank air compressor.

Refilling the tires with N2 as Costco is not really a good option as the tires heat up from the drive to Costco. I like to check my tire pressure and refill them after the the tire temperature has had about eight hours to cool down from driving. One needs to be aware of Boyle's Law with respect to gas temperatures and pressures when filling tires. Inflating a hot tire to the specified pressure will be a soft tire after it has cooled.

Really?

How does a nitrogen user purge the tire of atmospheric air to get the nitrogen content meaningfully above the natural 78% content?

--
GPSMAP64s, iPhone 12, Yaesu VX-8R w/GPS.

Don't

diesel wrote:

How does a nitrogen user purge the tire of atmospheric air to get the nitrogen content meaningfully above the natural 78% content

Don't be getting too technical. Got to ignore the original air (full of moisture)that was in that tire before the bead was sealed.
As to the original question.. to keep his tender fingers clean.

--
Lives in Edmonton AB A volunteer driver for Drive Happiness.ca and now (since June 20 2021) uses a DS65 to find his clients.

In reply...

diesel wrote:

How does a nitrogen user purge the tire of atmospheric air to get the nitrogen content meaningfully above the natural 78% content?

In reply to your question, a tire dealer will do two to three purge cycles and that will get the nitrogen content to about 93% to 95%. That is one of the reasons that tire dealers originally were charging for nitrogen when you purchased new tires.

--
John from PA

My car has no spare

That being said, I went ahead an purchased a Ryobi tire inflator (about $30 without a battery) that I leave in my car along with a tire plug kit from Harbor Freight. About once a month I swap batteries with a fresh one sitting on the charger. The benefit of the Ryobi is that it seals the valve stem completely and has an LCD display that I find very accurate. In a pinch, I can plug the tire on the roadside and be on my way. I have had to patch a couple in my driveway already, but I used the big 5 gallon compressor in my garage. One day when I'm bored, I'll try to see if that small portable will fully inflate my tire from dead flat.

https://www.homedepot.com/p/RYOBI-ONE-18V-Lithium-Ion-Cordle...

On sale now for $19.97.

--
Striving to make the NYC Metro area project the best.

interesting

mcginkleschmidt wrote:

I buy my tires from Costco for my two vehicles. I have an air compressor at home that I use to fill my tires about four times a year or sooner if the tires appear low.

Over a period of years, I'm not sure how much of the original nitrogen fill is left from the initial fill as the N2 concentration is diluted every time I refill my tires with my tank air compressor.

Refilling the tires with N2 as Costco is not really a good option as the tires heat up from the drive to Costco. I like to check my tire pressure and refill them after the the tire temperature has had about eight hours to cool down from driving. One needs to be aware of Boyle's Law with respect to gas temperatures and pressures when filling tires. Inflating a hot tire to the specified pressure will be a soft tire after it has cooled.

Is this concept with automatic transmissions. I had two cars only, with automatics, from 1990 to 1998. So suddenly in 2011, my wife's SUV is an auto (unlike when my sis in-law picked us up in a SUV it was a manual in 2012), and then my used car that I got 2016, also an automatic.

Suddenly I had to unlearn that I had thought my grandpa said shops have a machine to flush and exchange auto trans fluid.

No, drain and fill only?!!!! Then, some amount from 30-50% comes out, rest is left behind.

So in my analogy, me doing a drain and fill with fresh fluid, is like you adding air. How much of the original is left behind?

On my Toyota product I let the indie do it since no dipstick and ATF is highly sensitive to temp. The conventional wisdom is #1 you have 51% old, #2 you have 29% old, #3 you have 19% old, stop, good enough. I went to #4 which was like 11% old. See the diminishing returns? By this drain and fill process, one can never, ever, get to 0% old.

My wife's has a dipstick so I can drain and refill myself, and I did 2 until the color was pink (hardly scientific). It took like 5X adjusting the level even though I measured and put back what I took out. But again, had a dipstick.

Why can't all cars just be sticks lol it also helps when replacing the radiator to not have trans lines going to it. No idea why but my wife's car has a power steering cooler

^^Hey, newsflash... Cars

^^Hey, newsflash... Cars mostly not only shift themselves, but soon will drive on their own too! ...

Self Flying Cars Next

zx1100e1 wrote:

^^Hey, newsflash... Cars mostly not only shift themselves, but soon will drive on their own too! ...

The next step in the future will be self flying cars. Roads, you won't need no stinkin' roads, you'll have landing/takeoff/parking lots. You heard it first here on the POI Factory. shock

Yikes

mcginkleschmidt wrote:
zx1100e1 wrote:

^^Hey, newsflash... Cars mostly not only shift themselves, but soon will drive on their own too! ...

The next step in the future will be self flying cars. Roads, you won't need no stinkin' roads, you'll have landing/takeoff/parking lots. You heard it first here on the POI Factory. shock

It's hard enough looking left and right while walking around town. Now I'll have to look up too? Or should I just wait for the crunch sound and duck when people collide?

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Striving to make the NYC Metro area project the best.

Nitrogen in airplanes tires

The reason to use nitrogen in the commercial airplanes is to avoid the rise in the temperature in the tires during takeoff and landing. Due the friction created at high speed this increase the volume of the air and can cause the tires to blow, it was an air accident in Mexico several years ago and unfortunately the airplane crash and kill all on board, one or two tires from the main gear explode during climb and destroy some parts of the fly control of the airplane. Since then and after the investigation, now in all the airliners are mandatory the use of nitrogen in the tires.

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dysonsk

Root cause was overheating brake assembly

dysonsk wrote:

The reason to use nitrogen in the commercial airplanes is to avoid the rise in the temperature in the tires during takeoff and landing. Due the friction created at high speed this increase the volume of the air and can cause the tires to blow, it was an air accident in Mexico several years ago and unfortunately the airplane crash and kill all on board, one or two tires from the main gear explode during climb and destroy some parts of the fly control of the airplane. Since then and after the investigation, now in all the airliners are mandatory the use of nitrogen in the tires.

I think you are referring to the Air Mexico flight 740 flight in late March of 1986. In forensic engineering we talk about "root cause" and in that instance the root cause was determined to be overheating in a brake assembly. The overheating caused a tire rupture with consequent rupture of some fuel and hydraulic lines and cabin decompression. Because the one singular tire had been serviced with compressed atmospheric air that cause was deemed a major contributor to the accident. In the official report it was said that had the brake assembly been operating properly a high source of heat would likely not have occurred nor would the tire rupture likely to have occurred.

All this resulted in an Aircraft Advisory (FAR 25.733) which requires that all tires on braked wheels on airplanes heavier than 75,000 pounds be filled with dry nitrogen so that the tire contains less than 5 percent oxygen. (see https://www.govinfo.gov/content/pkg/CFR-2013-title14-vol1/pd...) for the text of FAR 25.733)

A summary of the finding relative to the accident are to be found at https://aviation-safety.net/database/record.php?id=19860331-...

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John from PA

Nice explanation!

Nice explanation!

RE :Root Cause Was Overheating Brake Assembly

I totally agree. something more to add. The airplane return to the gate before the flight due problems. The overheat in the long taxiing and associate with a overheating in the brake create the origin of this disaster. I am already a retired airline pilot. Thank you to explain in details to the members of this forum.
Best regards

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dysonsk