What is "Nitrogen Inflation?"

I saw a nitrogen inflation system in a Harbor Freight catalog, including green valve stem caps to warn someone that the tire is inflated with nitrogen.

My guess is that nitrogen does not retain as much heat as the air in the atmosphere so the tires radiate the heat to the atmosphere instead of to the air in the tire.

It doesn't oxidize the rubber, runs cooler, and is a larger molecule that doesn't escape as easily.

Pat

A gimmick. The only thing you're doing is replacing the approximately

20% of the total tire content. Regular old garden variety air is already 80% nitrogen. Whatever that 20% replacement is doing is minimal at best.

------------------------------------------------ The DNC - Building a bridge to the 19th Century.

Nope. Have a look at the periodic table of the elements. Oxygen is bigger.

------------------------------------------------ The DNC - Building a bridge to the 19th Century.

Heavier, not volumetrically larger. I'm thinking the heavier nucleus holds the electrons in a smaller orbital radius. See

helium is the really hot setup. :-) Pat

Nitrogen is totally dry.

Moisture in air, especially compressed air, can cause unpredictable temperature based pressure changes and can possibly degrade internal tire and rim materials.

To the poster who mentioned the green valve caps. Nitrogen is NOT hazardous in a tire. Nitrogen is only hazardous in concentrations high enough to displace breathable oxygen.

Nitrogen is used in race tires so temperature based pressure changes are predictable. It still changes.

More mass for O2, yes. Helium? Very expensive.

Hot setup? Pun intended?

------------------------------------------------ The DNC - Building a bridge to the 19th Century.

True. So why not just use dehumidified air? Far cheaper. As I said, it's a gimmick. It's getting a lot of laughs from those I know in the tire industry.

------------------------------------------------ The DNC - Building a bridge to the 19th Century.

None of those folks have ever been to a race track? Do these "tire industry" folks simply sell and install tires at retail outlets, or are they tire engineers?

It's not JUST the moisture.

Both. But I seriously doubt the average driver stresses his/her tires as is done on a track.

Of course not, but again, will a street car REALLY notice any difference? Not a rhetorical, but a serious question for you. I'd really like to know.

------------------------------------------------ The DNC - Building a bridge to the 20th Century.

It probably depends on the tire, load, driver, climate, etc... I notice pressure changes more in vehicles with larger volume tires and heavy loads much more than smaller volume and lighter loaded versions.

The 32's on my Jeep. and 33's on my pickup can change as much as 5-7 psi between hot and cold in the same season with typical compressed air. That much change does make a difference in the road feel. I don't use nitrogen as I'm pretty good at paying attention to air pressure at service time. For people who rarely check pressures from season to season, especially in larger vehicles, it might make sense.

My Jeep had one tire that would change a whole lot more than the other three. My only guess for the reason was water in the tire during mounting.

Considering that most people DON'T check their tires on a regular basis, it might make sense for some/most. Personally, I check mine about every two weeks. When tires get expensive (truck size or high perf), it just makes sense to take care of them.

------------------------------------------------ The DNC - Building a bridge to the 20th Century.

Helium would be terrible. It has a small molecule. Ever notice how fast "helium" ballons deflate (unless they are the mylar coated ballons).

Remember this - "Air" is already 80% Nitrogen. Most of the rest is Oxygen. The other stuff, including CO2, Water Vapor, etc. is trival.

N2 may be useful foir race cars. For street cars it is just a gimmick.

Ed

Oxygen is bad for the rubber inside the tire. Helium will leak out of the tiniest holes, which is why they use it for leak detection. Moisture isn't good, free water is even worse. And yes, the atmosphere is (iirc) 78% of the atmosphere, meaning part of that other

22% is trying to either leak out or oxidize the rubber.

For decades, they've insisted on nitrogen in aircraft tires, but until the advent of low-cost industrial nitrogen generation systems you had to buy it in high-pressure cylinders and pay through the nose, comparatively. If you aren't paying a lot to get it, running Nitrogen in car tires is a good idea.

I have the compressor - if someone wants to sell a small PSA nitrogen generator for a reasonable price (even if it's slow seeing as I'd only need a few liters a day at most, a 5-gallon receiver would be plenty) I'll get one.

-->--

Most of those laughing are usually high school educated mechanics that probably do not understand chemistry. These folks are usually afraid of any change and poke at it.

Absolutely true. Thus the smiley. Is there any relationship between atomic weight and molecule size?

The water vapor condenses in the air tank though. If you're spray painting, you need a water separator on the outlet hose and the tank needs to be drained regularly. The water that gathers in the bottom of the tank when not being used that gets churned into the tank air can often result in the gun "spitting" otherwise. Water isn't just a vapor in the typical air pressure tank. I used to do a lot of motorcycle projects and had occasion to cut a piece of old inner tube to make a rubber isolator. Every tube I did this with was wet inside.

I will say that information is not enough to convince me to go with nitrogen though.

Pat

I don't think people who actually work for the manufacturers are likely to be only hs educated.

As another here put it, it's a gimmick. The amount of O2 and water vapor isn't going to deteriorate the tire faster than it's tread life.

------------------------------------------------ The DNC - Building a bridge to the 20th Century.

Yup. It's used in leak detection for underground fuel tanks. Small molecules.

Give that man a ceegar.

------------------------------------------------ The DNC - Building a bridge to the 20th Century.

The gimmick is that nitrogen will not harm the rubber, as can happen with compressed air. The kicker of course is what ever damage that might been prevented in theory inside the tire will still take place on the out side of the tire. Put it on the list of high profit money makers for the dealership, along with fabric guard, paint sealant, door edge guard, window etching, rust proofing, 3000 mile oil changes etc. Save your money.

mike hunt

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