nitrogen or air. How to inflate tires

The Tale of the Miraculous Nitrogen Gas

You can inflate tires with nitrogen instead of regular air at many tire shops. The procedure will take some time and will cost about 100-200 hryvnia per set, depending on the diameter of the discs. Having received the money, the master will surely tell you that you don’t need to pump up the tires and you don’t even have to worry about periodically checking the pressure.

In the pumping process, special installations are used to produce nitrogen or cylinders with ready-made gas. The units purify the air and remove moisture from it, and then a special membrane system releases nitrogen. The output is a mixture with an oxygen content of not more than five percent, the rest is nitrogen. This mixture is pumped into the tire, after pumping air out of it.

For some reason, tire fitters call this gas inert. Probably, they all studied in schools with a humanitarian bias and did not study chemistry. In fact, inert gases are those that, under normal conditions, do not enter into a chemical reaction with other substances. Nitrogen is by no means inert.

So what does this miracle gas promise for those who decide to spend their time and money on such an event? If you listen to the same tire fitters, there are many advantages:

• maintaining a stable pressure with increasing temperature, since nitrogen has a coefficient of thermal expansion allegedly much lower than that of air;
• reduction of gas leakage through rubber;
• exclusion of corrosion of the inner part of the wheel;
• reduction in the weight of the wheel, which means a reduction in the load on the suspension and fuel economy;
• smooth running, soft passage of irregularities;
• reduction of tire wear;
• improved traction, cornering stability and shorter braking distances.
• reduction of vibration of the body and noise in the cabin, increasing the level of comfort.

All this looks like a fairy tale or a divorce, which allows you to make good money on a dummy. So it really is. But the funny thing is that many drivers who have pumped nitrogen into their tires claim that the ride has become more comfortable. Placebo works!

However, as you know, in every fairy tale there is some truth. Let's try to find out if it is in the statements of tire fitters.

Let's go through the points

Pressure stability with temperature change

The fashion for pumping nitrogen into tires came from motorsport, where the winner is often determined by a few hundredths of a second. But in the world of sports racing, there are completely different requirements, different loads on all parts of the car, including tires. And they do use various gases, including nitrogen.

The tires of Formula 1 cars are pumped with dried air, and the procedure is much longer and more complicated than pumping nitrogen in a conventional tire shop. The temperature inside the heated tire of the car reaches 100 ° C or more, and the main heating comes not so much from the friction of the tires on the track surface, but from constant sharp braking. The presence of water vapor in this case can affect the pressure in the tire in an unpredictable way. In the race, this will affect the loss of a couple of seconds and a lost victory. It has nothing to do with real life and driving around the city and beyond.

As for the fact that nitrogen allegedly has a much lower coefficient of volumetric expansion, this is simply absurd. For all real gases, it is practically the same, the difference is so small that it is often neglected in practical calculations. For air, the coefficient is 0.003665, for nitrogen it is even slightly higher - 0.003672. Therefore, when the temperature changes, the pressure in the tire changes equally, regardless of whether it is nitrogen or ordinary air.

Reducing gas leakage

The decrease in natural leakage is explained by the fact that nitrogen molecules are larger than oxygen molecules. This is true, but the difference is negligible, and tires inflated with air are stored no worse than inflated with nitrogen. And if they are blown away, then the reason lies in the violation of the tightness of the rubber or the malfunction of the valve.

Защита от коррозии

Nitrogen apologists explain the anti-corrosion effect by the lack of moisture. If dehumidification is actually carried out, then, of course, there should be no condensation inside the tire. But wheel corrosion is more pronounced on the outside, where there is no lack of oxygen, water, de-icing chemicals and sand. Therefore, such protection against corrosion does not make practical sense. But if you really want to, wouldn't it be easier and cheaper to use dehumidified air?

Reducing weight

A tire inflated with nitrogen is actually lighter than a tire filled with air. But not half a kilogram, as some installers assure, but only a couple of grams. What kind of reduction in the load on the suspension and fuel economy can we talk about? Just another myth.

Ride comfort

The increased comfort level when driving with nitrogen in the wheels can be explained by the fact that the tires are simply slightly underinflated. There are simply no other reasonable explanations. Gases are not softer or more elastic. At the same pressure, you will not notice the difference between air and nitrogen.

Other “benefits” of nitrogen

As for the fact that the nitrogen in the tires allegedly improves handling, shortens the braking distance and helps to reduce noise in the cabin, while the wheels are supposedly able to withstand more significant loads, these claims are based on false assumptions or simply sucked from the finger, so discussing them it makes no sense.

Conclusions

Whatever your tires are inflated with, in no case should you neglect to regularly check the pressure in them. Insufficient pressure can reduce wet grip, cause premature tire wear and increase fuel consumption.

The use of nitrogen is nothing more than a fashion. There is no practical benefit from it, but it will not bring harm to your car either. And if the nitrogen in the wheels adds confidence and good mood to you, maybe the money was not spent in vain?