[69887]

That is also why tire shops have become seemingly paranoid about having the best tread on the rear. If you have one tire replaced, they will put it on the rear.
I imagine their heads would explode if you brought them a high performance RWD vehicle with different sized tires and needed a new one for the front.

That is due to a well publicized multi-million dollar personal injury lawsuit against a tire shop, so now almost all tire companies (at least those who have lawyers) will insist that the new ones go on the rear. If you ask and experienced tire installers, I don't think they always agree, but they are required to follow corporate directives.

Personally, I think when buying only two new tires, putting the new ones in the rear of a FWD car is stupid, but you can't fight personal injury lawyers (ambulance chasers). You can change them when you get home.

 

[69887]

- did they really spec under-inflating their tires??
- what PSI did they recommend?
- what was the reason? traction/compliance/fluffy ride?

The old Explorers (like some other SUV's of their day) had a tendency to rollover during emergency handling maneuvers. In order to combat that, Ford specified lower air pressure in the tires, which turned out very close to the safety limit of the OEM Firestone tire. When tires lost a little air pressure during normal driving, it was below the safety limit of the tire.

By the same token, this is one reason why one should not exceed the recommended PSI on the door jam of an SUV or truck (at least exceed it by more than a couple of PSI) because you could be making the vehicle more prone to rollover.

 

[69887]

It was meant for everyone....same as YOUR comments about how good they are - are meant for everyone. It's an opinion.

Your opinion differs from mine....get over it and move on.

All I did was to say that in my experience (on my tires) that nitrogen leaks pressure less than air. I have no opinion about your experience with air or nitrogen.

I have no opinion with regard to what others should do, except that (as in many things besides nitrogen) if they want to know if something works, they should try it. Obviously the financial aspects of using nitrogen in tires may preclude many people from trying it, which I completely understand.

 

[69887]

Aren't all posts are opinions?

Yes, But some are opinions are meant for everyone (or at least anyone who owns that particular Toyota model/engine) and some are meant to apply to only themselves based on their own personal situation (including financial situation, proximity to a particular repair or auto parts facility, etc).

I try to take into account how old a vehicle is when someone asks a question or has a problem, and where they are located. That is not always possible, and not always relevant, but sometimes it does affect my response.

 

[69887]

Reading comprehension problem? No where did I tell anyone what decisions they should make. You can spend/waste your money anyway you want.

OK, but that is not how I took your comment. Comments such as "nitrogen is a scam" seem to apply to everyone.

There are many things members say (including myself) that are meant to be true for everyone, and those opinions that are just for me based on my own personal situation.

Because there are many on this forum that are not auto experts, some members rely on almost every word as to what others say, so I think it is best to make that distinction clear (whether it is meant for everyone or just for you). I try to make the distinction clear when I post on the forum.

For example, I have several times said that I would not recommend the use of Amsoil Signature motor oil in a Toyota (the XL or OEM lines are OK) because, although the Signature line is a high quality motor oil, the Signature line is not API certified (for a reason) and does not meet Toyota specifications. I also caution people to not use a European Formula motor oil (typically 0W-40, but not always) in a Toyota for similar reasons.

I also don't recommend the use of "oiled" K&N engine air filters, because they don't meet Toyota specs either. These recommendations are meant for every Toyota (at least those still in warranty), and not just my own personal opinion about what I would do based on my own situation.

 

[69887]

No... A responsible vehicle owner doesn't NEED a TPMS system. He can (and should) check his air pressure at every fuel-up, along with oil and other fluids. That's how we were taught in the 60s.
Unfortunately, most vehicle owners do not have a pressure gauge or tread depth gauge in their tool box... much less in their glove box.

Back in the 60's air was free at every filling station, and most were full service so they checked it for you if you asked. And the air was not filled with water, like many of the ones today that require quarters (multiple quarters for all 4 tires).

The TPMS is not to protect vehicle owners. Underinflated tires get poorer gas mileage, and the TPMS was made mandatory in order to reduce carbon footprint of automobiles, and to a lesser extent as a safety measure since underinflated tires can significantly reduce handling ability of a vehicle, and in some cases increase the likelihood of a rollover.

 

[69887]

Is it worth PAYING for it? Absolutely NOT.

Whether I personally agree with that or not, I try not to tell other people was kind of value decisions to make when it comes to spending money.

It is simply not possible expect people making $20K, $60K, or $200K per year to all make the same value decisions about what is most important to them.

Among the members of this forum, there is a vast range of how much money people have to spend, and so each person has to make those value decisions themselves, just like when it comes to things like what quality of motor oil, oil filters, etc, to use on their car.

 

[69887]

Are you saying that you ran your own controlled experiment? Maybe two tires with air, two with Costco nitrogen (and rotated regularly to null out force related differences)? Or do you have two identical vehicles with new tires that you ran simultaneously, one on air, one on Costco nitrogen? Can you share your results? Exactly how significantly different are we talking? Negligible (as reported by professional testers) or did you find some large margin that's a game changer and worth the hassle of going to Costco?

I have had tires with both nitrogen and air for the last 8 years, and it was not just tested on one brand/model of tire. Also, I have owned various tires for the past 50 years I have been driving. Obviously this is not enough to write an article in a scientific journal about it, but it is enough to satisfy me (along with many sources that have claimed that nitrogen leaks slower than air in most tires).

Each person can conduct their own experiment to determine what evidence they need to make a decision. However, even though I can personally see the advantages of nitrogen for my own vehicles, that does not mean I would pay extra for it, if it weren't free at Costco. I "might" pay a couple of dollars per tire extra with free refills at stores nationwide, but not more than that, since I have a fairly decent air compressor in my garage.

As far as my measurement equipment, here is the tire pressure gauge that I have used for about the past 10 years, which I posted about in other threads several months ago:
[ame]https://www.amazon.com/Measurement-Limited-Accutire-MS-5510B-Racing/dp/B000BNS7Y2/ref=sr_1_24?s=automotive&ie=UTF8&qid=1547749228&sr=1-24&keywords=accutire+tire+pressure+gauge[/ame]

Although a tire gauge, even the one above, may not have perfect absolute accuracy, the above gauge is very good at determining relative changes in pressure over time within 0.1 PSI. However, if anyone buys this tire gauge, I would recommend immediately replacing the batteries with higher quality ones, and make sure to have spare batteries available.

 

[69887]

The really great thing about science is that it's true whether you believe in it or not!

Once the smaller molecules filter out (water, CO2, O2, etc.) you are left with a near pure Nitrogen atmosphere. The diffusion rate of loss of the remaining larger single component becomes much slower and more predictable, and the Gas Law governs the temperature-related expansion/contraction. You've reached steady state. This happens whether you start with room air or concentrated nitrogen. It just takes more time with room air.

The piece that you might be failing to consider is the amazing strides materials science has attained in the field of polymers. ALL decent quality tires leak gas at a slower rate today than they did 10 years ago. 50 years ago (bias ply tires)? Not even in the same league.

Yes, science is great. I am one of the few people on this forum that regularly suggests to members that they try something (scientific experiment) instead of just theorizing about stuff.

My experience with multiple sets of tires is that they lose tire pressure much slower with nitrogen from Costco, as compared to air. That includes tires less tested with air that are only a few years old. I have to admit, I have not tried nitrogen from any other source besides Costco. I have used air from many sources, including my own air compressor.

With regard to bias ply tires, yes they are significantly different than radial tires, and I can't comment on how would react to nitrogen vs air.

But as with many other issues discussed on this forum (including octane levels), I frequently advocate the scientific approach and tell people to TRY IT.

Science does deal with theories, but without actual experiments to test those theories, not much scientific progress is ever made.

 

[69887]

) Unless your tire shop has a bulk delivery LN2 (liquid nitrogen tank = 99.999% purity - and very few do....), it most likely uses one of those N2 and O2 separators, sort of like that noisy compressor unit your grandma has that works like a reverse osmosis system. They typically deliver around 94% nitrogen when the filters are fresh.

I can't say for sure, but I suspect that Costco has fairly pure nitrogen. But whether it is 99% pure or 94% pure is irrelevant to me, because having had nitrogen in my tires from Costco for the last 8 years, I can tell you that tires with nitrogen from Costco definitely hold tire pressure better than air (based on about 50 years experience before that using air).

 

[69887]

I came across this great article @ Are nitrogen filled tires worth the cost...

https://www.lesschwab.com/article/are-nitrogen-filled-tires-worth-the-cost.html

it says precisely what all our members above have mentioned in here.

That article says the following:

"On new car tires, the cost can range from $70 to as much as $179. On existing tires, you’ll pay up to $30 per tire for service to drain air and refill with N2. Refills will run you $5 to $7 per tire."​

Notice they use the term "as much as." Those are not accurate numbers in my experience.

I bought my tires at Costco, where I was already a member. The price for the tires was the lowest I could find. Costco fills all new tires with nitrogen at no extra charge (they don't even ask you if you want nitrogen or air). Refills are free also, you just drive up to in front of the tire bays and someone will come up with a hose in a couple of minutes (at most) and fill you up to the PSI you tell them, even when they are busy with all the bays are filled.

It is very easy to say that nitrogen is not worth the cost, especially if the cost is exaggerated, and especially when there is no extra charge for nitrogen.

 

[69887]

FWIW...Sometime ago I put Michelin tires on my truck. They were filled with nitrogen & green color stem caps. Only thing I know for sure is...psi was more stable, air stays in tires longer. Noticed same on my HL. Over time have added small amount of air to tires (my compressor) & assume that dilutes nitrogen, but not really concerned. Ah, to use or not to use is the Q. :wink:

Unless they put the tire in a vacuum chamber when it is being filled with nitrogen, it will never be 100% nitrogen. But experience has shown that even 95% nitrogen and 5% air works reasonably well (which means that in the end, the tire will have 99% nitrogen and 1% oxygen, since air is 80% nitrogen).

So for every 1% of air added to a tire, only 0.2% of that is oxygen.

 

[69887]

A while back, I found a video posted by a company that provides N2 equipment for the aviation industry, and their video debunked the pressure/temperature differences claimed by tire installers. They had three identical cylinders, filled to the same pressure with air, Nitrogen, and CO2, painted black
They then temperature/pressure equalized all three cylinders, and put them out in the sun with a camera on the gauges. IIRC, these were at a couple of hundred PSI, so theoretically, any pressure change due to temperature would be exaggerated. The difference in pressure change from 60 degrees to 120 degrees was minimal... within a couple of PSI, insignificant when looked at as a percentage.

I never heard tire installers say that nitrogen responds dramatically different to pressure or temperature than air. If they did, they were just misstating what they were told, and probably did not do well in high school chemistry. What they probably meant to say is that nitrogen leaks less than air from a tire, so it stays properly inflated for a longer time.

When a gas heats up, or is compressed, the pressure does goes up. This is a fundamental law of chemistry. Not all gases respond identically, but air and nitrogen are pretty close (for obvious reasons).

But it is true that as a tire gets hotter (from rapid flexing of the belts under the tread when tires are turning at high speed) and the gas inside the tire heats up, that the tire pressure does rise, typically a few PSI, depending on speed, ambient temperature, etc.

 

[69887]

I'm willing to take the risk. I'm either using a gas station, my old shop, or using my tiny air compressor.

I have a small air compressor in my garage. Works fine. I open the drain valve after use each use, which lets the water drain out. When moist air is compressed, it condenses into water. Gas stations almost never (from what I can tell) drain their coin operated air compressors.

 

[69887]

His words, not mine. I just use whatever air pump I can find if I need air in my tires. If anything, using nitrogen is like having a CAI or maybe even expensive synthetic motor oil. You believe that it is good, so it must be good, but realistically it is doing good so little it does not matter and you are better off using something "normal".

I can almost guarantee you that nitrogen is far better than air that you get a gas station, where you have to pump in the quarters. Those air stations usually have a lot of water (not just moisture) in the air as it comes out of the hose, and that is bad for your tires. A properly maintained air compressor is a different story.

 

[69887]

Nitrogen is used in aircraft tires because it displaces oxygen, which helps reduce the risk of fire should a tire blow after gear retraction and damage hydraulic lines exposing the fluid to hot brakes.

Also, most aircraft fly in sub-freezing (and often sub-zero) temperature when at cruising altitude (33,000 feet or so). So if a tire has moisture in the air (the oxygen part of the air) it is not good for the tire if that moisture freezes or condenses into water.

 

[69887]

There are some advantages with MPG and tire trend, at least that is what my coworker says. Personally as long as I know that there is air in my tire (35 psi), I am fine.

The advantage is that nitrogen leaks less slowly than air from tires, so nitrogen filled tires are less likely to be under-inflated. If tires are inflated properly, the tire tread will last the same amount of time and MPG will be the same, on both air and nitrogen.