The main and not without meaning argument of opponents of nitrogen in tires is simple and obvious: the air is already 78 percent nitrogen, so what ...?! They will say that pumping tires with nitrogen is just a marketing ploy, that you shouldn't go for such a "scam", and they will sincerely consider you a real sucker who was deceived. But let's find out in order whether they are right and whether it is worth pumping tires with nitrogen!
Critics of nitrogen in wheels aren't wrong - indeed, air is mostly nitrogen. But not everything is so obvious and looks like a deception. And instead of imagining that for much less money they will pump you as much as 80% nitrogen instead of this number close to 100% and finally believe these critics, look at the composition of the air from the other side. Yes, air is mainly nitrogen, but it also consists of oxygen and a bunch of other gases, including environmental pollution, and also water vapor. That is, imagine that as many as 20% of unnecessary and harmful impurities for the tire will be removed - you see, this is a completely different view of pumping tires with nitrogen - more rational, and it seems that, indeed, it is worth pumping tires with nitrogen.
But let's be clear: the general idea of pumping nitrogen into the wheels of a car is that much less oxygen and water will remain inside the tire, and instead, the tire will be filled with neutral and much more useful nitrogen for the tire. Why is it useful and what is harmful to oxygen and water? The fact is that an oxygen molecule is much smaller than a nitrogen molecule, so oxygen can (and will) seep out through the layers of rubber, depriving the tire of what it needs. But another disadvantage of air is that a significant amount of water can form inside the tires due to the presence of the same oxygen, as well as directly water vapor in the air. This is indeed the case. And since water can corrode the metal of the wheel, you definitely don't want it to sit there for too long. Nitrogen is much drier than oxygen. This water vapor at a certain temperature tends to condense and accumulate due to the force of gravity in small puddles inside the tire, which causes imbalance during driving, which is not "cured" by balancing.
Vapors of nitrogen (left) and air (right) - the latter seep through the tire
Thus, why it is worth pumping tires with nitrogen is because:
- You do not have to inflate your tires with nitrogen as often as if you inflated them with air,
- you will not have water accumulations inside the wheel.
By providing greater fuel savings by maintaining the correct tire pressure that nitrogen provides, money can be saved on inflation and periodic tire inflation.
Nitrogen in the tires of many commercial vehicles, as well as buses in Europe and the United States is not a mandatory requirement, but it is widely used. In our country, this service is still a novelty for most car owners. Nitrogen pumping went to the masses from the Formula 1 racetracks, the wheels of cars began to be filled with a nitrogen mixture in this particular class. The technical regulations of the races do not oblige to use any particular type of mixture, the teams are free to inflate the tires with ordinary air or nitrogen at their discretion.
The better to inflate tires
In fact, there is no consensus even among professional motorists. Some have a positive attitude towards this, with the suggestion of manufacturers of nitrogen gas generators, as well as car services that offer this service, which paint in paints the many advantages of nitrogen in tires. Others are sure that this service is just another way to siphon money from not very knowledgeable car enthusiasts. So what, in fact, is this service, how useful is it?
Air and nitrogen characteristics
From the school course, many of us know (remember) that the air around us consists of a mixture of nitrogen and oxygen, and nitrogen in this mixture is almost 80 percent, 20 percent oxygen, and some other gases, including carbon dioxide, dilute this mixture. A nitrogen generator can increase the nitrogen content by up to 95 percent. How much does this additional 15 percent nitrogen improve performance characteristics tires?
Should you inflate tires with nitrogen?
Pros of nitrogen versus reality
The main advantage of a saturated nitrogen mixture in tires is a higher level of safety. This is due to the difference in the coefficient of expansion with temperature changes. For nitrogen, this figure is seven to eight times lower than for oxygen. When driving, the tires warm up, the pressure, respectively, increases. Sometimes changes can exceed 0.6 atmospheres, which is a lot, and can lead to tire damage. This is especially true for summer time and for high-speed cars. But! If you pump pure nitrogen into the wheels, then you should not count on a sevenfold decrease in the numbers. These are calculations for an ideal gas, while oxygen and nitrogen begin to show significant discrepancies only at very strong pressures, up to several MPa.
This means that under normal operating conditions there will be no serious difference in tire pressure, even a few devices will show thousandths. The effect of using nitrogen increases in proportion to the increase in the diameter of the wheel itself, therefore Europeans and Americans use it mainly in large vehicles.
Pros and cons of pumping tires with nitrogen
The second advantage of nitrogen is less leakage, since the size of the nitrogen molecule is larger than that of oxygen. Yes, in reality it is, but in practice this means that with periodic pumping of air, the nitrogen content in the tires will increase, since oxygen molecules will escape faster. The third plus in the nitrogen piggy bank is the peculiarities of chemical properties, which help to reduce corrosive processes, slow down the aging of tire materials. What does this give the driver in practice? Practically nothing, because in real life, from the influence of various factors on it from the outside, nothing inside has time to oxidize, etc. It's not even worth talking about reducing the weight of the wheel, because the difference is negligible.
But still…
If we weigh all the pros and cons, we can say that nitrogen certainly has its positive aspects, but all these advantages are much more modest than it is presented by supporters. And if you take into account the cost of the service, then there are reasonable doubts about the practical benefits for an ordinary car owner.
15 november 2017In recent years, tire shops have been trying to popularize a new service - filling car tires nitrogen instead of normal air. This topic has become overgrown with many fables and myths, since sellers endow the "nitrogen" rays with fictitious advantages, and opponents put forward theories that have not been tested in practice. Why to pump up the wheels with pure nitrogen and what real advantages the driver gets, read in this publication.
Gas injection technology
It is known from the school physics course that the ambient air already contains 78% nitrogen (meaning volume fractions). The remaining 22% is distributed between oxygen (almost 21%) and a dozen different gases, whose share is about 1%. Also, water vapor is dissolved in the air, constituting from 0.2 to 2.5% of the volume of gases. This value changes depending on the weather, the period of the year and the latitude of the area.
The essence of the technology is simple: to extract 78% of the gas from the air and fill automobile cylinders. In practice, nitrogen injection into tires is done as follows:
- The wheel valve is connected with a hose to an automatic vacuum-nitrogen plant.
- After switching on, the unit completely sucks the air mixture out of the tire.
- Having passed it through a system of special filters and a dehumidifier, the unit produces nitrogen with a purity of at least 95%.
- The cleaned gas is pumped into the wheel in compliance with the pressure required by the manufacturer.
By processing normal air, the nitrogen generator not only removes oxygen and other impurities, but also traps water vapor. This fact should be taken into account in further consideration of the issue in order to separate the real pros and cons of the procedure from myths.
Reference. The technical specialists serving Formula 1 races and various rallies do not have this question. The ramps of all fireballs are filled with nitrogen by default.
Real and fictional benefits
To begin with, it is worth listing all the advantages indicated on the billboards near the tire shops. What does the use of nitrogen in the cylinders of a car give, according to the assurances of the sellers of the service:
- constant tire pressure regardless of the ambient temperature and road surface;
- improving traction and slowing down tread wear;
- the movement of the machine becomes softer;
- tires do not deflate over time;
- shortening the braking distance and improving acceleration dynamics;
- the likelihood of tire explosion under load is markedly reduced.
When the rubber heats up, the pressure does not increase
All drivers who rock the slopes on their own are aware of the effect of thermal expansion of air in tires. The bottom line is as follows: when warming occurs on the street, the gas in the cylinders expands and the pressure in the wheels increases by 0.2–0.5 bar. And vice versa, after the onset of cold weather, the rays "sag". Advertising claims: the coefficient of thermal expansion of nitrogen is 7 times less, so the pressure in the tires practically does not change.
Opponents of this theory rely on the laws of physics, according to which all gases expand in the same way. That is, the difference in pressure in the wheels, pumped with nitrogen and air mixture, is negligible.
In practice, the situation is different: pumping tires with nitrogen really allows you to keep the pressure at the same level, regardless of the temperature outside. Probably, the presence of water vapor in the air, which is absent in a nitrogen medium, plays a role here (remember - the gas is dried before injection).
Improving the performance properties of rubber
The adhesion of the wheel running surface to the road surface depends on many factors, including:
- rubber properties, product quality;
- shape, pattern and design of the tread;
- the size of the contact spot and the distribution of efforts in it;
- type and condition of the road surface.
The kind of gas injected into the tire has no effect on grip and tread wear. You can artificially change the pressure in the slopes and in this way increase or decrease the contact patch, but the contents of the balloon does not matter. The statement is not true.
Soft car ride
Another answer to the question of why to fill the tires with nitrogen is as follows: a cylinder inflated with this gas is not as elastic as an air one. As a result, the wheel bounces less from bumps in the road, the ride becomes more comfortable, and the suspension lasts longer.
The argument is explained by the lower specific gravity of nitrogen compared to air, although in reality the difference is small. There is an interesting point here: the specific gravity of the air mixture is a variable value that depends on temperature and moisture content. If you upload cold air at minus 20 ° С, then the weight of 1 m 3 is 1.396 kg, warm (+10 ° С) - 1.248 kg.
Practical observations have shown that a softening of travel is felt when driving over small bumps in cars of a budget price category with a classic suspension. In business and premium cars, the improvement in comfort is not felt, as they use an efficient multi-link suspension.
Stingrays do not descend
The advertisement says: a nitrogen molecule is larger than an air particle, so it does not "crawl" into rubber microcracks, which inevitably form as a result of operation on uneven roads. Therefore, the tires do not deflate for a long time and do not require inflation.
The statement is classified as absurd. The difference between the air and nitrogen particles is so scanty (0.02 nanometers) that in the event of a crack, the molecules of both gases will freely penetrate into it. What happens in practice: for the same period of time, the "air" wheel loses 0.5 bar, filled with nitrogen - 0.47 bar.
Improved ride quality and safety
When the tires are inflated with nitrogen, the acceleration dynamics are improved and the braking distance of the vehicle is shortened. This argument is a logical consequence of the false statement about the increase in grip on the road surface. This means that in reality the acceleration and deceleration of the car remains unchanged, and the advantage is fictional.
Riding safety is improved on the basis that nitrogen ramps explode less. There is some truth in such conclusions: tires burst from heavy load and heating, which causes the air pressure in the cylinder to rise to critical. Nitrogen is more tolerant of an increase in temperature and does not give rise to pressure, therefore, rubber explodes less often.
Obvious disadvantages
In general, it is beneficial to inflate tires with nitrogen. It is not for nothing that this gas is widely used in the field of circuit races and rallies. There are only two downsides:
- decent price of the service;
- impossibility of pumping and loss of nitrogen mixture in case of a puncture of a wheel on the way.
Compared to conventional air, the cost of filling with nitrogen is 5–10 times higher, depending on the region. Knowing what the real disadvantages and advantages this procedure gives, you will make the right decision about using the service. It certainly won't do any harm.
What for? Filling tires with an air mixture has a number of disadvantages, which can be avoided using the modern method of inflating tires with nitrogen:
- The air mixture causes oxidation processes inside the tire. Oxygen and moisture contained in the air mixture destroy the inner hermetic layer of the tire and provoke corrosion of the steel cord. Nitrogen contains no oxygen and moisture impurities that cause corrosion.
- The pressure inside a tire is unstable when it is inflated with an air mixture, as oxygen expands when heated by movement. Driving on tires with the wrong pressure leads to increased tire wear, reduced vehicle stability, reduced braking and adhesion properties of tires, ride comfort (the car reacts more sharply to unevenness), and overall road safety. The thermal expansion coefficient of nitrogen is lower than that of oxygen and avoids the dependence of pressure on temperature.
- The need for swap. The nitrogen molecule is larger than the oxygen molecule, due to this, nitrogen seeps through the rubber micropores more slowly, pumping is required 40% less often.
To summarize, Benefits of Using Nitrogen to Inflate Tires are as follows:
- Increased tire life - preventing premature aging, tire depressurization and rim corrosion;
- Reducing the likelihood of tire damage as a result of improper pressure in it;
- Stability of tire pressure, frequent checks and inflation are not required;
- Reduced fuel consumption correct pressure provides low rolling resistance.
Thanks to these factors, not only the efficiency of the tire is increased, but also the safety of its operation. In this way, increased safety is the main advantage, which ensures the inflation of tires with nitrogen.
How is it going? The process includes the following steps:
- V working system the nitrogen generator is injected with compressed air for processing, not less than eight atmospheres.
- Multilevel filtration is carried out, during which moisture, impurities and oils are removed from the air.
- The purified air is passed through membranes separating only nitrogen -n2 molecules. The result is nitrogen with a purity of more than 95%.
- Nitrogen supply to the inner cavity of the tire by means of a compressor.
Why MBO? Using the service of filling tires with nitrogen in the Trade and Service Centers of the Moscow Military District, you can be sure that we use high-class equipment and the quality of the work performed. Tires are pumped with nitrogen in the MVO Trade and Service Centers using professional equipment Nitro Ride (Great Britain), which allows you to get and pump nitrogen into tires with a purity of up to 99.9%, without moisture and other impurities.
Providing the service of inflating tires with nitrogen, we take care of your safety and your car.
Most car enthusiasts have come across a proposal to inflate their tires with nitrogen. Is it worth doing this procedure, and what benefits can a car owner get? Consider the pros and the most common myths.
Tires are inflated with nitrogen as follows:
- At the first stage, special equipment pumps out the air mixture from the wheel.
- Then the tires are filled with nitrogen containing no more than 5-10% of other gases, including oxygen.
For freight transport the requirements for the quality of nitrogen filling are more stringent. No more than 5% of other gases are allowed in the form of nitrogen impurities.
What do they promise in a car service and is it true
The opinions of car enthusiasts about inflation of tires with this gas vary greatly. Some drivers claim that the difference between oxygen and nitrogen is significant. Others say that they did not notice the difference, which means that the expensive procedure was useless.
Car service workers promise a significant change in the behavior of the car, as well as the quality of driving after injection of inert gas.
Let's analyze the most common statements.
The risk of an explosion of the wheel is eliminated, since there is no oxygen in it
Nitrogen proponents argue that the wheel will not explode because the gas does not support combustion. But any driver understands that air does not explode inside the wheel. The tire bursts - and as a result of the sudden release of gas under pressure, cotton is obtained.
That is, if a wheel inflated with a nitrogen mixture breaks, there will be the same cotton.
But a leading question arises: how often do motorists observe a wheel explosion with a fire on city streets?
The tire is lighter
This will require the help of science.
The mass of the "cube" of air is 1.29 kg, nitrogen - 1.25 kg. One wheel holds 0.078 kg of air or 0.075 nitrogen. That is, the difference in the mass of the four wheels is about 10 grams.
Stable tire pressure
Again we call physics for help.
Gay-Lussac's law says that the volume of a gas depends on its temperature at constant pressure. That is, every gas has the same expansion volume when conditions change.
That is, air, or any other gas, when heated in tires, will expand with the same rate. Pressure will change with temperature.
Wheels do not require pumping
Another statement is that there are more nitrogen molecules than oxygen, so the wheels are less likely to release pressure.
The difference between gas molecules is 0.000000002. That is, both gases will seep through microcracks in the rubber at the same speed.
Reduces disc and rubber corrosion
It's true. This is where chemistry comes to our rescue.
Oxygen reacts even at low temperatures. It is this gas that is considered a strong oxidizing agent that causes metal rust and rubber aging.
Nitrogen in this respect is stable and does not contribute to the destruction of materials.
