The domestic auto industry rarely pampers us with new vehicles, so there is no particular variety of Russian cars on the roads. However, many motorists who own cars such as VAZ 2107 or 2114, or 2115 do not seek to part with them and for many years roam them across the expanses of Russia. What is the reason for such popularity of Lada in our time - this is the second name of these machines, no one can explain. Everyone has their own reasons not to part with an "old friend".

Since many models of VAZ cars have not rolled off the assembly line for a long time, it is not necessary to expect that they will be equipped with the latest functions. Naturally, they are in complete trouble with safety, except for the seat belt, there is no protection. Experienced drivers increase the percentage of their life safety by always monitoring the tire pressure of a VAZ car. In addition, it allows you to reduce the wear and tear of the transport, which is important.

Impact of tire pressure on safety

It is impossible not to assess the correctness of pumping the wheels, because this has a significant impact on the condition of the components of the car, as well as on the safety of the driver, his passengers and other road users.

• If the tires are inflated differently, not corresponding to the values \u200b\u200bindicated in the passport for the vehicle, then the car may behave unpredictably while driving.
• When a lot of air is pumped into the wheels and the pressure goes off scale, then there is a high probability of tire rupture. And when driving, the braking distance is greatly increased, the dynamic performance deteriorates.
• Lack of air is no less dangerous, especially in the cold season, as the stability of the car and cornering deteriorates, and problems with extreme braking also arise. The pressure in VAZ tires in winter should be slightly higher than in summer.

All this leads to serious consequences and terrible accidents.

• Improperly inflated tires wear out faster.
• Since the dynamics of the car deteriorates, as a result, more fuel is consumed.
• Driving becomes worse, especially in winter and on wet surfaces.
• The quality of braking suffers.
• Suspension damage is very likely if it falls into holes in the road.

Do not pump the wheels or do not pump them. This could cause death or serious damage. Particular attention should be paid to lovers of Lada cars, which are not distinguished by their safety.

What about the WHA?

The optimal pressure in the tires of a VAZ 2107 will differ from the pressure in the tires of a VAZ 2114 or any other car. This is due to the fact that each car has its own weight, disk size. In addition, operating conditions and other factors must be taken into account. That is, everything matters: the season, the climatic zone, the load, etc.

In order to inflate the wheels as correctly as possible, this is especially important in winter, you need to look at the vehicle operating instructions. There is information about which wheels need to be installed on the car and what air pressure should be in them for normal driving.

It is worth paying attention to the tires, as a rule, on their lateral side there are extremely permissible pressure values.

In VAZ cars, most of the rims have a radius of 13, which denotes R13, but they need to be inflated in different ways.

Automobile model	Tire size		Optimal tire pressure
	Front pair	Back pair	Front pair	Back pair
VAZ 2107	165/80 R13	165/80 R13	1.6	1.9
	175/70 R13	175/70 R13	1.7	2.0
VAZ 2114/2115	165/70 R13	165/70 R13	1.9	1.9
	175/70 R13	175/70 R13	1.9	1.9
Lada Kalina	175/70 R14	175/70 R14	1.9	1.9
	185/60 R14	185/60 R14	1.8	1.8

Tire pressure Lada in winter and summer

Car manufacturers do a great job of calculating the optimal tire pressure, so there is no reason not to trust the written information in the passport for the car. Especially carefully this issue was approached in Soviet times, when the production of Lada cars began.

Pressure gauge

Although many car enthusiasts have their own opinion on this matter and believe that it is necessary to adjust the inflation of tires depending on the season and the rubber used.

• Winter tires are slightly softer than summer tires, so it is recommended to pump them harder.
• When driving on winter roads, the indicators should be slightly higher than normal.
• In the summer, it is advisable to lower the pressure a little, since the air expands when heated.

Listening to the opinion of experienced drivers or clearly following the recommendations in the car passport is a purely individual matter. One thing is for sure - one cannot deviate greatly from the optimal values, no more than 10-15% is permissible

How to measure pressure

In cars such as the VAZ 2107 or VAZ 2114, of course, there are no automatic monitoring systems already installed at the factory. Therefore, the driver must take care of himself.

for measuring tire pressure

There are several types of devices that can monitor tire pressure. They have different capabilities, which accordingly affects the cost and usability.

• For those who value their life infinitely and safety is not just a word for them, there are special tire pressure monitoring systems. Their installation is not easy and the cost is high, but there are a lot of positive qualities. They allow not only to inflate the tires perfectly, but also to monitor any changes in pressure, which makes it possible to timely eliminate all deficiencies and problems.
• Various types of pressure gauges: mechanical, electronic, should always be in the arsenal of any driver. Each type has its own pros and cons, as well as a significant difference in cost.
• The most primitive devices are cap devices. They do not show exact numbers, but their color scale will indicate normal or not pressure in the tire.

Every driver in his lifetime has time to try all types of devices and choose the most convenient model. Do not forget about the accuracy of the device, not all of them differ in it, as well as the specifics of use.

For a long time, VAZs will drive along our roads, deftly maneuvering between proud foreign cars. Indeed, despite the lack of advanced options in most models, they have proven themselves well. And, if their drivers still pay close attention to the tire pressure of VAZ cars, then driving safety will be higher.

When inflating the tires of any vehicle, it is always necessary to maintain the pressure set by the manufacturer, since failure to observe this important rule negatively affects the operation of the tires, and also affects the further safety of road traffic. What should be the correct pressure in the tires of the car (table). Let's talk about the dependence of the degree of pumping on weather, road conditions and methods of testing.

What happens if tire pressure is not observed

Most cars with front-wheel drive (both domestic and foreign) can be fitted with rims with a radius of R13 - R16. However, the basic equipment almost always includes wheels in sizes R13 and R14. The value of the optimal pressure in the tires of the car is selected according to its mass at full load. In this case, the climatic and road conditions in which the vehicle is operated must be taken into account.

If the wheels are inflated incorrectly

If the wheels are over-pumped

• The wear of the running gear parts increases. At the same time, while driving, all the bumps and pits on the road are felt. Driving comfort disappears;
• as the tire pressure of the car becomes excessive, as a result, the contact area of \u200b\u200bthe tire tread with the road surface decreases. Due to this, the braking distance is significantly increased and the safety of vehicle operation is reduced;
• the tread wears out faster, significantly shortening the service life of car tires;
• excessive tire pressure on contact with an obstacle at high speed can cause a hernia or even rupture of the rubber. This situation is extremely dangerous and can lead to tragic consequences.

Most owners of transport equipment with R13 and R14 wheels (the most common radius values) are interested in: what should be the optimal pressure in a car's tires? According to the recommendation of the manufacturer of the tire of the thirteenth radius, it is necessary to inflate up to 1.9 kgf / cm 2, and wheels with the size R14 - up to 2.0 kgf / cm 2. These parameters apply to both the front and rear wheels.

Dependence of tire pressure on climatic and road conditions

In principle, it is necessary to maintain the same wheel inflation both in summer and winter. However, it is recommended not to slightly inflate the tires in winter. This is necessary for:

1. Improving vehicle stability on slippery roads. Driving becomes more convenient and comfortable with slightly flat tires in winter.
2. Road safety is improved as the vehicle's braking distance is significantly reduced.
3. Running flat tires in winter softens the suspension, resulting in less poor road surface conditions. Mobility comfort increases.

You also need to know that with a sharp change in temperature (for example, after the car has left a warm box in the cold), due to some physical properties, there is a decrease in tire pressure.

Therefore, before leaving the garage in winter, it is imperative to check the tire pressure, and if necessary, pump them up. Do not forget about constant pressure control, especially when the temperature regime changes and in the off-season.

The recommended pressure in R13 tires with the onset of summer is 1.9 atm. This value is calculated taking into account that the car will be half loaded (driver and one or two passengers). When the vehicle is fully loaded, the pressure value of the front wheelset must be increased to 2.0-2.1 atm, and the rear - to 2.3-2.4 atm. The reserve should be pumped up to 2.3 atm.

Unfortunately, the road surface cannot be called ideal, so most motorists specifically prefer not to pump the wheels a little. Because thanks to this, all the bumps and flaws in the road are not so felt when driving. Often in the summer, the pressure in the wheels is reduced by 5-10%, and with the onset of winter this figure slightly increases and is 10-15%. When driving on flat roads, it is best to maintain the tire pressure recommended by the manufacturer.

Taking into account all factors, a tire pressure table is built.

What should be the optimal pressure for larger wheels

Despite the fact that most of domestic and foreign cars have wheels with a maximum radius of R14, most owners still install larger wheels (R15 and R16) to improve the appearance of their vehicle and improve some of its characteristics. Therefore, you need to know what is the optimal pressure for a tire of this size?

It also depends on the degree of load on the machine. When it is half loaded, the tire pressure threshold should not exceed 2.0 kgf / cm 2, at full load this value is already 2.2 kgf / cm 2. If a large amount of various heavy luggage is transported in the luggage compartment, the pressure in the rear wheelset must be increased by another 0.2 kgf / cm 2. As you can see, the pressure in the tires of the fourteenth radius is approximately equal to the pressure in R15 and R16.

How to measure pressure: the correct sequence

Alas, even most experienced drivers completely ignore the procedure for monitoring the pressure of the wheels of a car, considering this procedure to be absolutely useless. The tire pressure is checked using a pressure gauge, which can be integral with the pump, or be a separate element. Do not forget that the error of any manometer is usually 0.2 kgf / cm 2.

Pressure measurement sequence:

1. It is necessary to zero the pressure gauge reading.
2. Unscrew the safety cap (if any) from the wheel nipple.
3. Connect a pressure gauge to the nipple and push it slightly to purge air from the chamber.
4. Wait until the arrow of the device stops.

This procedure must be performed monthly with regular vehicle operation. Measurement should be done before driving, when the rubber is not yet warmed up. This is necessary to accurately determine the readings, since after warming up the tires, the air pressure inside them increases. This is often the result of dynamic driving with constant changes in speed and hard braking. For this reason, it is ideal to measure before driving, when the tires on the car have not yet warmed up.

Whether or not to pump the tires with nitrogen

Recently, almost all tire changing stations have appeared an expensive service of filling tires with nitrogen. Its popularity is due to a number of the following opinions:

1. Thanks to nitrogen, the pressure in the tires remains constant as they heat up.
2. The service life of rubber is increased (it practically does not “age”, since nitrogen is much cleaner than air).
3. Steel wheel rims do not corrode.
4. The possibility of tire rupture is completely excluded, since nitrogen is a non-combustible gas.

However, these statements are nothing more than another advertising move by marketers. After all, the nitrogen content in the air is about 80%, and it is unlikely that anything can change for the better if the nitrogen content inside the tires increases by 10-15%.

In this case, you should not spend extra money and pump up the wheels with expensive nitrogen, since there will be no additional benefit, as well as harm, from this procedure.

The recommended tire pressure of the vehicle can be found in a special table located in the vehicle operating instructions. Depending on the car brand, manufacturers indicate the optimal pressure at which the load in the tires will be evenly distributed.

The concept of tire pressure should be understood as the density of the air pumped into the tire by the compressor. It is necessary to inflate tires taking into account the data of tables of pressure in tires of cars and trucks. The correct pressure ensures an even distribution of the load, affects the following parameters:

• fuel consumption;
• uniformity of tire wear;
• safety of movement of the machine.

There are several options for which the specified parameter will not be optimal:

• tires are inflated - the density of the inflated air is too high;
• underdeveloped tires - this parameter is underestimated;
• all wheels of the car have different pressures.

Correct pressure ensures reliable adhesion of the tires to the road surface and affects the comfort and safety of movement. You can find out how incorrect tire pressure affects tire wear by looking at Figure 1.

Figure 1. Influence of tire pressure on tread wear

In the first variant, the tire is under-inflated to the permissible norm, excessive wear of the tread along the edges of the rubber occurs. In the second version, the tire is inflated to the required rate - the tread wear is even. The third option shows an over-inflated tire - the middle part of the tread wears excessively.

In real operation, after twenty minutes of driving at high speed, the tire pressure increases by 0.5 atmospheres. Long journeys at high speeds can lead to an increase in the specified parameter up to 4-5 atmospheres. In this situation, an over-inflated tire may burst while the machine is moving.

Wheels lowered to half the atmosphere can affect the "behavior" of the car, increasing the risk of accidents. It is recommended to check the tire pressure once a week, as well as before long trips.

Influence of various factors

You can check the air density of the tires using a pressure gauge. It is recommended to carry out this procedure inside a garage or box with cold tires. The temperature difference between the moving and standing wheels is significant: while driving, the tire heats up. In this case, the air supplied inside it has the ability to expand when heated and reduce its volume during cooling.

Tire Air Density Measurement Procedure

From a theoretical point of view, pumping up the wheels to normal pressure values \u200b\u200bis not difficult. From a practical point of view, everything is not so simple: having inflated tires on the street to an acceptable value in winter, you can see that during a trip, the pressure inside the tires will change. It is possible to solve this problem by pumping up tires in winter inside a warm garage or box after two hours of inactivity of the car.

In summer, the cooling of tires is very slow, so the wheels are pumped up after the trip when the tires have completely cooled down. Many car enthusiasts argue that the permissible tire pressure is different in winter and summer, so in the summer you need to under-pump the tires to the permissible norm, and in the winter - to pump the tires. This is a misconception. The tire pressure recommended by the vehicle manufacturer is the same in winter and summer, motorists need to monitor this parameter and try to keep it within the normal range. Under-pumping or over-pumping of wheels leads to a deterioration in the adhesion of tires to the road surface, and reduces the tire life.

The tire pressure is influenced by the location of the tires on the front or rear axle. The axle load of the vehicle differs significantly. An even distribution of the load is called weight distribution, it is optimal if 50% of the loads fall on the front axle and the same amount on the rear, but in real conditions it is impossible to achieve such a distribution of loads. Therefore, the load on the tires of the front and rear axles is different, for example, compare the data in the tables below.

Tables with the values \u200b\u200bof the recommended tire pressure of cars by make

Toyota

Recommended tire pressure for Toyota cars: Camry, Corolla, Starlet, Rav 4, Karina, Selica, Supra, Lexus GS 300, Previa Salon (4x4), Lit Ice, 4-Runner, Land Cruiser 4x4 (Starlet, Corolla, Carina, Camry, Celica, MR2, Supra, Lexus GS300, Previa, Saloon (4x4), Model F (4x4), Lite Ace, 4-Runner, Landcruiser 4x4, RAV 4).

Alfa-Romeo

Bmw

Chevrolet

Chrysler, Dodge and Jeep

Recommended tire pressure for Chrysler, Dodge and Jeep cars: Cheri Voyage, Vision, Saratoga, Le Baron, Viper RT 10, Cherokee / Wangler (Voyager, Vision, Saratoga, Le Baron, Viper RT 10, Cherokee / Wrangler).

Daewoo

Daihatsu

Fiat

Honda

Hyundai

Recommended pressure inside tires of Hyundai cars: Pony, Lantra, Sonata, S-Coupe, Getz, Santa Fe (Pony, Lantra, Sonata, S-Coupe, Getz, Santa Fe).

Kia

Recommended air density for tires of KIA cars: Serato, Sid, Rio, Carens, Sportage (Cerato, CEE'D, Rio, Carens, Sportage).

Lancia

Recommended tire pressure of Lancia cars: Delta, Dedra, Tema (Y10, Delta, Dedra, Thema).

Mazda

Recommended tire pressure of Mazda cars: 3, 6, 121, 323, 626, Xedos.

Mercedes

Recommended pressure inside tires of Mercedes cars (C, TE, E, SL, SE / L / C, GE, GD).

Mitsubishi

Recommended tire pressure for Mitsubishi cars: Colt, Lancer, Galant, Sigma, Eclipse, Space, Pajero (Colt, Lancer, Galant, Sigma, Eclipse, Space, 3000GT, L300, Pajero).

Nissan

Recommended tire pressure for Nissan cars: Micra, Sunny, Primera, Prairie, Serena, Maxima, Terrano II, Patrol (Micra, Sunny, Primera, 100NX, Prairie, Serena, 200SX, 300ZX, Maxima, Terrano II, Patrol).

Opel

Recommended tire pressure for Opel cars: Corsa, Combo, Astra, Cadet, Vectra, Caliber, Omega, Senator, Frontera, Monterey (Corsa, Combo, Astra, Kadett, Vectra, Calibra, Omega, Senator, Frontera, Monterey).

Peugeot

Recommended tire pressure for Peugeot cars (106, 205, 306, 309, 405, 505, 605).

Porsche

Recommended tire pressure for Porsche cars (944, 968, 911, 928, 959).

Renault

Recommended pressure in tires of Renault cars: Espace, Express, Twino, Safran, Laguna, Alpina (Express, Twingo, R5, Clio, R19, R21, R25, Safrane, Laguna, Alpina, Espace).

Skoda

Recommended tire pressure for Skoda cars: Favorit, Forman, Cordoba, Fabia, Roomster (Favorit LX, Forman LX / GLX, Cordoba, Fabia, Roomster).

Subaru

Recommended tire pressure for Subaru Subaru cars: Wagon, Vivio, Justy, Impreza, Legacy, Forester, Outback (Wagon, Vivio, Gli, Justy, Impreza, Legacy, XT Turbo, SVX, Forester, Outback).

Volvo

Recommended pressure inside tires of Volvo cars (240, 440, 460, 850, 480, 940, 960).

Audi

Citroen

Recommended tire pressure for Citroen cars: Xantia, AX, C 15, ZX, BX, XM, C2, C3, C4, C5.

Ford

Recommended tire pressure for Ford cars: Fiesta, Curier, Escort, Sierra, Mondeo, Proba, Sation, Taurus, Aerostar, Explorer, Maverick, Focus I, Focus II, Fusion (Fiesta, Courier, Escort, Sierra, Mondeo Station, Probe , Scorpio, Taurus, Aerostar, Explorer, Maverik, Focus I, Focus II, Fusion).

Volkswagen

Recommended tire pressure for Volkswagen vehicles: Polo, Golf II, Golf III, Vento, Corrado, Passat, Caravel, Synchro 4x4, Jetta 2005, Ruareg (Polo, Golf II, Golf III, Vento, Corrado, Passat, Caravelle, Synchro 4 × 4, JETTA 2005, TOUAREG).

Vaz

Recommended pressure inside tires of VAZ cars: 2104, 2105, 2106, 2107, 2108, 2109, 21099 2110, 2111, 2112, 2114, 2115, Lada Kalina, Lada Priora, Niva.

Please note that the optimal parameter of the density of the injected air is influenced by the car brand, the location of the tires on the front or rear axle, the size of the tires (for radii R13, R14, R15, R16 .. the specified parameter is different) and the load of the car.

Conclusion

The fuel consumption of the car, the load on the chassis, the resource of tires, and controllability depend on the pressure in the tires. An increase in the ambient temperature leads to an increase in the density of the air injected into the tires; with a decrease in the air temperature, a decrease in the tire pressure is observed. Therefore, the density of the air with which the tires are inflated is checked after the rubber has completely cooled down: tires cannot be pumped immediately after a long trip. In winter, pump up tires in a warm garage or box, so you get as close as possible to the optimal density values.

With large differences in air temperature, measure the specified parameter more often. Consider: the load on tires, regardless of the season, increases when the car is fully loaded, therefore, adjust the density of the air pumped into the tires depending on the operating conditions of the vehicle.

Car tire pressure is a question that all motorists are interested in. Tire wear and other important parameters depend on this indicator. Many people are interested to know how much they save money by pumping up the tires of a car by 0.5 atm from the recommended value, and how much gasoline is consumed when using a car with under-pumped tires.

Unfortunately, not everyone measures the pressure in R19 tires or any other with a pressure gauge - some control "by eye" is enough, which is fraught with unforeseen consequences.

This issue is especially important due to the temperature difference in summer and winter, which has a significant effect on the degree of tire inflation.

Optimal car tire pressure

To find out what the increased or decreased pressure in tires R13, R15, R19 is fraught with, and whether the pumping characteristics of the wheels of a car or truck should be changed at different times of the year, you need:

• look at the results of many tests;
• refer to the tire pressure table from the manufacturer - it will help you study the standard indicators. It contains minimum, normal and maximum pressure.

The tire pressure monitoring system will help you to control the necessary indicators in the wheels. It is installed in the car interior and provides prompt information to the driver about the condition of the wheels while driving.

Tire pressure monitoring system

How temperature affects tires

The fuel consumption, the load on the chassis and the frequency of buying new tires depend on what pressure should be in the R19 tires. When the outside temperature rises, the pressure in the tires of the car increases with it. Conversely, the colder it is outside, the lower this value. There is a table for changing the optimal pressure in R19 tires depending on the air temperature:

These figures are presented for a passenger car at partial load (minimum number of passengers and cargo in the trunk). At full load, the discrepancy between the indicators will increase. The standard indicators for this wheel size vary depending on the car model and range from 2.2 to 2.7 atm.

It is because of the temperature that the pressure in the wheels differs significantly at different times of the year, which affects fuel consumption.

Tire pressure gauge

For correct inflation of cold tires (when the ambient and rubber temperatures are the same), refer to the tire inflation standards established by the manufacturer or written in the vehicle passport.

You should also take into account that when pumping rubber indoors (service station, garage), you need to increase the atmospheric pressure in the tires in winter by 0.2 bar. This will help compensate for temperature differences. In the summer, you don't need to adhere to this rule, because there is almost no temperature difference.

Also, if you constantly need to pump up the R19 wheels, pay attention not only to temperature differences, but also to:

• the degree of wear of the wheel;
• fastening the nipple;
• the state of the tubeless valve;
• the quality of the air mixture in the chamber.

If you do not want to change the inflation value of the R19 wheels in summer and winter, fill them with nitrogen. It does not respond to temperature fluctuations and maintains constant pressure over a long period.

The essence of the test

To find out what pressure should be in the tires to save fuel and drive comfortably, the experts conducted a test on a Lada 112 car with Kleber Viaxer summer tires installed. There were 2 passengers in the cabin, the trunk was empty.

Criteria	Under-inflated summer tires (1.5 ATM)	Inflated summer tires (2.5 ATM)	Standard (2.0 atm)
Wear	around the edges	centered	the manufacturer guarantees the longest possible service life
Gasoline consumption (in relation to the standard)	+2%	-1,6%
Coasting from a speed of 80 km / h	1108 m	1232 m	1176 m
Maximum speed on the "rearrangement"	61 km / h	87 km / h	66 km / h
Distance of the brake at the boundary value of wheel blocking on a dry surface	44 m	45.9 m	45 m
Controllability (course stability, ride smoothness)	high ride smoothness, almost complete lack of sensitivity to surface irregularities (9 points out of 10); decrease in exchange rate stability (7 points out of 10)	increased exchange rate stability (8 points out of 10); reduced ride smoothness - all patches and bumps are felt (6 points out of 10)	normal stability on the road surface, heading control. (8 points out of 10)

Thus, the pressure in the tires in the warm and cold seasons affects the technical characteristics of the car (in this case - "Lada 112"). Its correct performance ensures optimal fuel consumption and savings on the purchase of new tires.

Features of pumping wheels at different times of the year

Tire tightness is checked when the vehicle has cooled down after a long trip or being in a warm room. Accordingly, there is no need to pump tires immediately after a long trip. Also note that:

1. In the hot season, the car will slowly cool down.
2. It is worth swinging the wheels of your car in cold weather in a warm room (tire fitting, boxing). This fact will help to avoid pressure differences and bring the pumping rate closer to the ideal for you.
3. The pressure on the tires, regardless of the season, increases when the car is fully loaded (when it has the maximum number of passengers and cargo in the trunk), so pump up the tires in time.
4. With large temperature differences indoors and outdoors, more often measure the pressure in the tires of the car to quickly adjust it.

Any Autoreview test begins with a pressure gauge and a tire pump. After all, we, like many of our readers, know perfectly well what effect tire pressure has on the behavior of a car. But in life, there are often cases when lazy motorists climb into the trunk behind the pump only after colleagues standing next to the traffic light pay attention to the half-flat tires. And there are other things - omniscient craftsmen categorically assert that tires with a pressure of three atmospheres drive longer and improve all characteristics of the car, without exception ... To once again show what consequences both increased and decreased tire pressure can lead to , we decided to experiment with the editorial VAZ-2108, "shod" in tubeless tires Bl-85 dimension 175/70 R13.

In motion, each wheel of a car, among others, is acted upon by a force numerically equal to the product of the rolling resistance coefficient by the weight of the car per given wheel. This coefficient varies in a wide range (from 0.007 to 0.3) depending on the type of road surface, travel speed, size and design of tires, as well as the temperature and air pressure in the tires. Since the topic of our work is precisely pressure, then we note that the rolling resistance coefficient decreases with increasing tire pressure. And only at unrealistic values \u200b\u200bof 5-6 atmospheres in operation, an inverse relationship is observed. This happens due to a decrease in losses associated with deformation of tires during rolling - a rigid tire is less wrinkled and, accordingly, loses less energy to heat the internal structure during deformation. And even more - the area of \u200b\u200bthe contact spot decreases.

Reduced pressure, on the other hand, greatly increases tire heat and energy loss.

Everything seems to be simple: swing the wheels more and the car will roll better! But at the same time, at least, losses in comfort are inevitable - an over-inflated tire stops damping the ulars when driving over irregularities. But it's not just about comfort.

The pressure in the wheels and on the handling of the car has a huge impact.

The manufacturer must indicate the value of the air pressure in the tires of the front and rear axles, which can be different, and often it is also specified what pressure to apply in cases of full or partial load, when driving at medium or high speeds.

So, let's modulate three variants of incorrect tire pressure: too high, too low and normal, but ... with one half-flat tire.

Option one: hypertensive crisis

The driver, pumping up the half-flat wheels, asks himself the question: “Why don't I blow in more air for future use, and forget about the pressure in the wheels until autumn? And in theory, the car rolls better on pumped-over wheels and consumes less gasoline ... "

No sooner said than done. The pressure in all tires is raised to three atmospheres instead of the recommended 1.9-2.0, and our "hypertensive" goes on the road.

First of all, using a professional research complex, we measured the maximum speed, fuel consumption, coast and braking distances. What turned out to be?

The difference compared to the normal version (with a tire pressure of 2.0 atm) is noticeable, and, in full accordance with the theory, the "eight" with "hypertensive" tires outperforms the "healthy" one in all these parameters, except for braking distance and smoothness course. The car has become easier to roll; due to this, the "maximum speed" has increased, and fuel consumption has somewhat decreased. But with brakes, the effect is the opposite - an over-inflated tire has less grip and, as a result, the braking distance has increased.

How has the behavior of the car changed? "Hypertensive" has become more sporty in its reactions, it reacts more sharply to steering turns, it has become easier to control the trajectory. In extreme situations, wheel breakdown in sliding occurs earlier, and in addition, the effort on the steering wheel has decreased - now in sharp turns you spend less energy holding the steering wheel. But as a result, the already too small reactive effect on the steering wheel in the "near-zero" zone completely disappeared.

On the smoothness of the course, our forecasts were not fully justified. We expected a more significant increase in vibration, strong shocks when driving over irregularities, but there was no significant deterioration in comfort. Only driving on cobblestones and on broken asphalt showed a slight increase in vibration transmitted to the body by the hard tires. It was more annoying that all the bumps became too hard blows to the steering wheel, and especially in the corners.

In addition, in motion, due to a decrease in the contact patch, the central part of the tread will wear more, and therefore the service life of the peen tires will be significantly reduced.

Option two: chronic hypotension

We kneel before our inflated tires and release two atmospheres, leaving only one locked up. Now all the wheels of the G8 have one atmosphere each. The option is quite realistic, because under reduced pressure, a radial tire with soft sidewalls does not change shape much, and a quick glance at the wheels is often not enough to say that they are flat.

But the measuring equipment cannot be tested. She clearly recorded the deterioration of all parameters, and quantitatively the difference with the "standard" was greater than in the case of excess pressure.

In motion, while driving in a straight line, you don't feel much difference. But it is necessary to turn the steering wheel a little, and the increased "tenacity" of the steering is felt instantly: the effort on the steering wheel has more than doubled. Well, it's very hard to turn the steering wheel! The "hypotonic" car became like some kind of "smear". The sensitivity has sharply decreased, and now it is necessary to turn the steering wheel at clearly large angles in the same turns, and the car still tends to go outside the turn.

At the limit, the reaction to gas discharge is very sluggish, almost none. There were less vibrations from the road, but mostly it affected small irregularities, and on more significant potholes and cobblestone pavement, the shaking is no less than at normal pressure. In addition, decent pits and asphalt steps now need to either go around, or reduce the speed to almost zero - otherwise a “tied” disk and a punctured tire are guaranteed.

In addition, for tubeless tires suffering from "hypotension", there is another danger - the possibility of disassembly in a turn or when obliquely hitting an obstacle (for example, a curb). We had to experience this despite our own desire. The fact is that the test program included our standard maneuvers - "rearrangement" and "turn". The lowered tires survived the "rearrangement", but in the "turn" the limit came - and in the fifth race the tire, having emitted the last atmosphere pumped into it, was "dismantled". And only thanks to the experience and reaction of the expert sitting at the wheel, it was possible to keep the wheel, the tire, and the car intact. If this happens in a tense turn on a regular road, disastrous consequences are guaranteed ...

Option three: pierced

In the case when the tire "gives off the spirit" quickly during a puncture, everything is clear - the spanking sound and shaking will tell the driver that it's time to stop and get the "spare". But it often happens differently: you "catch" a nail and drive for a rather long time, not noticing a slow decrease in tire pressure. This is especially true for tubeless tires. Can this be detected and by what signs? What riding can lead to

with such a "gift"? We were able to answer these questions by conducting an experiment on our G8.

To begin with, one of the rear wheels was “punctured”. The pressure in it is one atmosphere, and it is almost impossible to notice by eye that the wheel is flat. In the movement, we also did not notice any peculiarities in the behavior of the VAZ-2108 - the front-wheel drive car reacts poorly to the hooked rear wheel. And only by bringing the car to sliding, "unwinding" it from side to side, one can feel the "asymmetry" in the behavior of the "eight". When the "sick" wheel is outside the center of the turn, the car heels more and "screwed" inward, leaving for a smaller radius. And in the opposite turn, the behavior of the car is again normal.

Thus, it is possible to recognize a lowered wheel on the rear axle in motion only in extreme modes. And with normal driving, there is only one tool for this - a pressure gauge.

If the pressure has dropped in the front wheel, then everything is much simpler - the increased effort on the steering wheel is instantly felt, and the car begins to "pull" towards the flat tire. If you continue to move, you can feel almost all the "charms" of the car's handling "hypotonic", not excluding the possibility of "slipping" of the tire from the disk in a turn. And this is already very dangerous.

Influence of pressure in tires of the Bl-85 model (175/70 R13) on the parameters of the VAZ-2108

Tire pressure, atm
Maximum speed
(IV gear), km / h
Car runout, m
Fuel consumption, l / 100 km
Braking distance, m
Maximum speed
performing a maneuver
"Changeover" (20 m), km / h

The lack of atmospheres in the tires is perfectly felt in extreme modes

Disassembly in motion. Fast but unsafe

Having in hand the results of measurements and analyzing the driving experience on under-inflated and over-inflated tires, let us give some recommendations. First of all - keep the data in the tires of the car in accordance with the recommendations of the manufacturer, do not be lazy once again to get the pressure gauge and pump.

The pursuit of improving the performance of the car by increasing the tire pressure is hardly worth it - the gain is minimal and is accompanied by side effects. Even supporters of the "cowards need brakes" principle cannot but worry about the decline in tire life.

But careless driving on half-flat wheels not only leads to a deterioration in all parameters of the car, but also threatens a serious accident.