I surf Huntington most days before work.

By the way, I used nitrogen in my tires and shocks back in my racing days and did note in my comment that it is better than air. For me, it is not worth paying to use it in a street car.

 

This is directly from Tire Rack's website, and explains the whole subject pretty well, including how the air is removed to increase the percentage of nitrogen:

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.

Tire Vacuumed
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.

While inflating tires with nitrogen never results in 100% purity, most nitrogen service equipment providers advise that reaching at least a 93% to 95% purity is necessary to receive the desired benefits. This ratio is normally achieved by initially purging the tires of existing air (down to just a few psi) and then refilling them with nitrogen. The purge/fill cycle is often repeated to achieve the desired level of nitrogen purity.

Note: Tires should never be subjected to a vacuum in an effort to eliminate the oxygen. Distorting the tire as shown in the accompanying picture can be as detrimental to the internal structure of the tire as running over potholes and road hazards.

So what should drivers do?
Overall, inflating tires with nitrogen won't hurt them and may provide some minimal benefits.

Is it worth it? If you go someplace that provides free nitrogen with new tires, why not? Additionally we've seen some service providers offering reasonable prices of about $5 per tire (including periodic adjustments for the life of the tire) to a less reasonable $10 per tire (with additional costs for subsequent pressure adjustments) or more as part of a service contract, which we believe exceeds the value of nitrogen's benefit.

Rather than pay extra for nitrogen, most drivers would be better off buying an accurate tire pressure gauge and checking and adjusting their tire pressures regularly.

 

Nitrogen put in the tires is a gas and as a gas, it must obey the laws of nature and physics. As such, the pressure in nitrogen-filled tires will increase in warmer weather and decrease in colder weather, although not quite as much as regular air.

So several statements that the owners didn't have to add or delete nitrogen to maintain the exact same pressure is absurd.

 

I use it but don't pay extra and would not pay extra. In my experience it maintains pressure better than "air", so why not use it if you see a benefit. And, like any benefit, decide for yourself what it's worth to you.

 

Just like NFL footballs must also obey the ideal gas law, except nobody knows the temperature INSIDE the football, where it counts.

 

No. I work for a dealership (Mercedes-Benz). Not worth it. No.

 

Ill guarantee that they have no nitrogen tank on site. The dealers use this as a money maker. The machine they have is just an air dryer which removes the moisture from the air going back into your tires. Is it better than moisture filled air compressed air....Yes Is it worth 79 dollars No ****in way.

 

Unless you run Nascar, Indy or F1 it's a waste of money! The last time I worked the pits at a SCCA race no one ran pure nitrogen in their tires. They did calculate how much the pressure would change once the tires got to operating temperature but that's all. It's unnecessary marketing hype to make extra money. Kind of like the nitrogen enriched gasoline they promote nowdays. Never trust marketing.

 

I run nitrogen in all 5 of my cars and will never switch back to plain air. Those that talk against it have never run nitrogen. I have to laugh at comments like the pressure always stays the same. Nitrogen, like all the other gasses in the world, expand with temperature.

The main reason I like nitrogen is the simple lack of maintenance and piece of mind. I adjust the tire pressure about twice a year, whereas when I was running air it seemed like I had to add air every couple of weeks. Sure, it was just a pound or two, but still it was a pain. Two of my cars are driven by other people and I know the pressure is always correct, and during oil changes, the dealer will set then to the proper pressure.

Air is for young guys that want to keep dragging their air compressor out.

 

It sounds like a lot of people in this thread slept during HS science and/or physics classes. However, to keep this from becoming a clone of the "How often to change oil" threads, just do whatever makes you happy. It's that simple.

 

http://www.edmunds.com/car-care/shou...-nitrogen.html

Is Nitrogen Worth It?
The air we breathe is made up of 78 percent nitrogen, 21 percent oxygen and a few other elements. To get the desired benefits for tires, nitrogen needs to be at least 93 percent pure, according to nitrogen service equipment providers quoted on Tirerack.com. So we're basically talking about adding an extra 15 percent of nitrogen and getting rid of as much oxygen as possible.

Based on cost, convenience and actual performance benefit, we don't think nitrogen is worth it. A much better use of your money would be to buy a good tire-pressure gauge and check your tires frequently. This is a good idea even if you have a tire-pressure monitoring system in your vehicle. The warning lights aren't required to come on until you have less than 25 percent of the recommended tire pressure. Having the correct tire pressure will get you many of the benefits of using nitrogen and will ensure that your tires last longer.

http://www.tirebuyer.com/education/nitrogen-vs-air
The truth of the matter is that nitrogen does have some scientific advantages over air, but they lie at the upper reaches of the tire performance spectrum, and it’s debatable if the average driver will reap any benefits from using nitrogen. Let’s take a closer look at some of the factors in the argument and see if we can help you decide which is right for you.

Summary: Your choice depends on how you use your vehicle

So where does all this information leave us? As we’ve seen, nitrogen does have some technological advantages over air for tire inflation. Whether or not those advantages will be of any practical use to you depends on how you use your car. Certainly, if you fall into one or more of the categories below, using nitrogen could be beneficial:

If you have one or more cars that are primarily used at the racetrack
If you drive very sparingly and your car sits unused for an extended time
If you own collectible cars that are seldom driven any great distances
If you have to put your car in storage for a significant period of time

If you use your car on a regular basis for daily driving and don’t fall into any of the above categories, it’s difficult to see how using nitrogen gives you any practical benefits, especially compared to its cost and inconvenience. But it’s your call – nitrogen does no harm to your tires and if you’re interested, you can test it out. If you don’t like it or don’t see any benefits, you can always go back to the free (or almost free) alternative that we’ve all used successfully for years: air.

http://www.cartalk.com/blogs/tom-ray...n-filled-tires

Dear Car Talk:

My questions involve the nitrogen-filled tires on my 2011 Subaru Outback. These were on the car when I bought it, and I was assured that they had advantages over air-filled tires. But this was kind of a last-minute decision, and I confess I didn't do any research into the matter. My husband and I are snowbirds, and recently, just before leaving for Florida, I had a flat tire.

This brought questions to mind, since not all garages are equipped with nitrogen: (1) Is it OK to drive a car with one air-filled tire and three nitrogen-filled tires, as suggested by the fellow who changed the tire? (2) Can existing nitrogen-filled tires be refilled with air? (3) Would it be more practical to just bite the bullet and buy four new air-filled tires? (I dread the expense!) My main concern is driving between North and South on the interstates and getting a flat, in the middle of nowhere, and not having access to a nitrogen supply. I'll look forward to your answer!

-- Clem

Car Talk: Great questions, Clem. And the answer, as my brother would have said, is: fuggedaboutit.

I think the nitrogen-filled-tire thing is a scam. Obviously, as you were in the final hours of purchasing your new car, they sold you on a bunch of add-ons. You bit on the pinstripes, the pom-pom on the antenna in the shape of Vladimir Putin and the nitrogen-filled tires. And all that only added $30 to your monthly payment! Congratulations.

The argument they make is that the nitrogen doesn't contain oxygen, like normal air does. That's said to give you several advantages if you put it in your tires:

They say the oxygen in the air degrades the rubber more than nitrogen does. They say nitrogen molecules are slightly larger than oxygen molecules in the air, so it's less likely to leak through the rubber. They say if you use pure nitrogen from a tank, there's no water vapor in it, like there is in the air we breathe. Water vapor can affect pressure variation when the tires heat up, and can cause corrosion. And then some salesmen have claimed that if you have an accident and there's a fire, if your tires explode there won't be additional oxygen to further fuel the flames.

Every one of these arguments has an iota of truth. But they're all completely overblown. And in my opinion, it's a total waste of money to put nitrogen in your tires.

First of all, air is already 80 percent nitrogen. So even if you go to the gas station and fill your tires at the ding-ding pump, you're getting mostly nitrogen anyway.

Second, even if nitrogen limits the degradation of the rubber, your nitrogen-filled tires are still exposed to air on the outside of the tires! And once the outsides of the tires degrade, you have to replace them.

Third, nitrogen molecules are slightly larger than oxygen molecules, but it's not like we're having an epidemic of air seeping through rubber tires in this country. Tires in good condition don't leak.

Fourth, a small variation in tire pressure while driving is normal. Pressure increases as the tires heat up. If you're driving a race car at 200 mph, half a pound of tire pressure might make a difference, but you and I will never notice it.

Fifth, before you spend a lot of money preventing water vapor in the air inside your tires from hastening the corrosion of your wheels, remember that the other 99.5 percent of your car is always exposed to air -- and water vapor.

And finally, if your car is already on fire, to the point that it causes your tires to heat up and explode, a slightly brighter flame around the wheel wells will be the least of your worries.

So to answer your specific questions: It's fine to drive a car with three tires filled with nitrogen and one tire filled with air (80 percent nitrogen); it makes no difference whatsoever.

Existing nitrogen-filled tires can be refilled with air at any time, to any degree. The tires don't care what's in them.

And no, it would not be practical to buy four new, air-filled tires. Your tires are fine, and there's no need to replace them just to change what they're filled with. As they need air, fill them with air from any convenient gas station. And over time, try to forget that you ever heard the word "nitrogen."

Good luck, Clem.

 

Some people have more brains than common sense. To them I say, if it makes you feel warm and fuzzy inside,get the Nitrogen,but keep it to yourself to avoid being laughed at!!!

 

I was using pure nitrogen when I was racing in Gt1. The other nice thing of having a tank was the ability to run air tools. Nitrogen would grow about 8 psi on average compared to 12 average psi on compressed air.

 

No, unless it's free. The advantage gained must match or exceed the cost

 

If it is free, .....if it is convenient,..... if it easy to get to,... and it doesn't harm anything..then why not?...I do however agree one should not pay for this service,and as I have stated, Costco does this for free, nada, zip, nothing.
just saying.....

 

Just a quick fyi...they use nitrogen generators to make their nitrogen, past the cost of the machine and a little extra time to refill the tires, it's all gravy for the dealers. It is kinda cool how automated it is.

If you're interested this explains the process

 

Partially correct. The only advantage of nitrogen in a C6 tire is lower moisture content. The nitrogen still gets up to the same temperature as the rubber. The nitrogen still obeys the ideal gas law and expands increasing the tire pressure. But the tire will actually run slightly warmer since water will condense from a normal air fill and convert to water vapor as the tire warms. This does NOT correspond to the ideal gas law and so the pressure will be a little higher which will make the tire a little firmer which will make it run slightly cooler. The net, however, is that the pressure will change roughly 10% less with nitrogen. i.e. with a 3 pound change as the tire warns, nitrogen will only change 2.7 pounds.

Uh, no. They use nitrogen because they can bring an easily available small tank of nitrogen at 2,000 psi or they can try to compress the same amount of air in a reasonably sized tank on their own. The former is FAR more economical.

You live in Florida where the temperature doesn't change as much. If you lived up north you would understand how wrong it is to say nitrogen doesn't expand and contract. The difference between nitrogen and normal air is negligible. Not zero but negligible.

See above for the reason Indy and NASCAR use nitrogen. Airplanes use nitrogen because it won't add oxygen to a tire fire in the wheelwell.

I would respectfully suggest that it is time for you to do your research.

OP, Garry's quote from Tirerack has your answer. It MIGHT be worth $5 a tire but not $10 and certainly not $20. It is just another scam to increase the profit margin on sales.