Among the many different prerequisites for traffic safety, tire pressure also has a significant effect. This factor should not be neglected. Control over it is one of the rules that must be strictly observed. A pressure difference of even three-tenths of an atmosphere is fraught with sad consequences, especially in difficult weather conditions or when the quality of the roadway is far from ideal.
It is not uncommon to see a car moving on lowered wheels. Without thinking about what such negligence can lead to, many drivers drive, pumping them up from time to time.
At any time of the year, the wheels must be inflated to the optimum pressure. However, not all car owners pay at least some attention to the condition of the tires, if they are not lowered almost “to zero”.
Any car has a factory instruction manual, in which each automaker clearly indicates the optimal tire pressure for their offspring. Deviation of tire pressure from this level can lead to various problems with the entire machine.
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Tire pressure can become “wrong” even if you personally checked it; when the tires were changed at the tire shop; when the wheels were changed in the autumn, and the workshop worker pumped 2 atmospheres into each wheel (the room was about 25 ° C). Winter came and the temperature outside the window dropped to, say, -20°C. Air, like all bodies, contracts when cooled. And the air in the tires too.
A temperature difference between 25 degrees Celsius and 20 degrees Celsius will reduce the tire pressure from the original 2 atmospheres to about 1.7. During the ride, the air in the tire, of course, heats up a little and slightly compensates for the pressure drop. But only slightly. On under-inflated wheels, even in summer, any car behaves as if it were driving through a jelly. It obeys the steering wheel much worse, strives to go out of the turn, does not keep the trajectory even on a straight line.
The braking distance of a car with unflattened wheels increases by several meters. And now let's add to this disgrace such invariably winter attributes as slush on the pavement, freshly fallen snow or ice.
Riding on flat tires in such an environment turns into a real roulette (get / don't get into an accident) and keeps the driver in constant tension during the trip. About increased tire wear due to low pressure in a situation where, before an accident, it is no longer necessary to mention it.
Advantages of an underinflated tire in winter
- The car's patency is improved, both on snow and on ice. If you can “exaggerate” a slightly lowered wheel softer, it has a larger contact patch with the road than a fully inflated one, due to this, the patency increases, both on snow and on ice.
- Such a wheel “swallows” road bumps better, that is, a car ride is more comfortable.
Cons of an underinflated tire in winter
- Slightly increased fuel consumption. If you do not pump 0.2 atmospheres, then fuel consumption will increase by 0.2 liters. Due to the fact that the car rolls worse, it is more difficult to push a flat tire. Not critical - it seems to me that patency is more important.
- Wear of rubber. If the wheel is under-inflated, then theoretically this figure should increase. But 0.2 atmospheres is not the pressure that strongly affects wear. Rather, it will be so minimal that you won't even notice it. So you can safely lower it to such a small indicator.
- The maximum speed will be slightly less. However, guys, I advise you not to drive much in the winter! Sometimes there are such drifts on the roads that it is difficult to drive at a speed of 60 km / h, I am already silent about higher rates. Remember in winter the main thing is cross-country ability, not speed!
But the reverse situation is also possible, when the wheels are pumped. This can happen, for example, when a driver walks out to the car on a frosty morning and discovers that all of its wheels have deflated according to the thermal compression scenario described above. What will a caring owner do?
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That's right - he will take the pump and pump them up to 2-2.2 atmospheres, as indicated in the instruction manual. And in a week, thirty-degree frosts will disappear and another thaw will come - as it often happens recently in the European part of Russia. The air in the wheels, like everything around, heats up and raises the pressure much higher than required - up to 2.5 atmospheres or more. When the car starts to move, the wheels heat up even more and the pressure in them jumps even higher. The car rides on pumped wheels - it jumps like a goat over stones. The course becomes extremely rigid, the body and suspension are shaken by powerful vibrations even on a seemingly flat road. And getting into a hole, which the driver would not have noticed with normally inflated wheels, can even lead to the destruction of the tire and disc.
In order not to face technical difficulties on the way, the driver must monitor the level of tire pressure and be able to control its permissible level.
After all, if the wheels are too pumped, then this complicates practical control. vehicle. The original article lists the main dangers that a driver can expect in the presence of excessive elasticity of the wheels.
What can high blood pressure affect?
To some extent, tightly inflated tires become the key to more economical use of fuel. But even this small difference in gas mileage is hardly able to cover the shortcomings of a similar negative phenomenon.
And it consists of the following main risks:
- High rigidity does not contribute to vibration damping, so the process of controlling the machine becomes much more complicated.
- The suspension of the car under the influence of various shocks will quickly become unusable.
- All road irregularities will become extremely noticeable for the driver and passengers.
- Steering and ball bearings receive excessive mechanical stress.
- Traction is broken, and this is the risk of accidents.
With all this in mind, we can definitely say that tire pumping should not be allowed. Otherwise, the car can quickly become unusable or even get into an accident right on the highway.
So important closely monitor the level of pressure present inside the wheels. This criterion is of paramount importance not only for a beginner, but also for an experienced driver with extensive experience and practical skills.
Why it also affects comfort
It is extremely difficult to drive a car when it feels like the tires are poorly inflated or completely pumped over. Therefore, it is worth monitoring them at least once every 2 weeks, as well as promptly correcting existing malfunctions.
When the tires are inflated, people inside the cabin clearly feel:
- every hole in the concrete road, when the car, as if by an invisible force, is thrown up, and it does it very sharply;
- vehicle vibration;
- a sharp movement of the car when the brake system is working.
It also happens that companies responsible for the transportation of passengers also make a mistake in their work related to the excessive elasticity of the wheels in their cars.
But in this situation, customers have every right to write complaints about the quality of services provided to a similar carrier. And here their claims will be fully justified.
If it is possible to maintain a clear control regarding the level of pressure inside the wheels, then the driver must do this and take into account all the nuances in practice.
Otherwise, he risks not only his health and even life, but also the safety of all passengers and people in the salons of cars passing nearby.
It is always better to monitor the condition of the tires yourself, without the help of outsiders. So it will be possible to quickly determine their condition, as well as carry out the necessary repair or adjustment work.
Specialists involved in the study of tire characteristics and the design of new models have long identified an interesting relationship. Every 0.15 bar increase in the operating pressure range of 2.0-2.5 bar results in a 5% reduction in rolling resistance. This happens because with increasing pressure, the radial deformation of the tire decreases due to an increase in its rigidity. And smaller deformations unequivocally reduce hysteresis losses in the rubber and cord layer. But note that the rolling resistance of a tire is only a fraction of the overall drag that a car experiences while driving.
Resistance to the movement of the car in the general case is provided by:
- Rolling resistance force of all wheels. This parameter gradually increases with increasing vehicle speed.
- The force of air resistance. Air resistance depends on vehicle speed, vehicle cross-sectional area and drag coefficient. The dependence on speed is quadratic, that is, air resistance imperceptible at low speeds absorbs the lion's share as it accelerates.
- Overclocking resistance force. The car very rarely drives evenly and in a straight line. Road conditions forced to slow down and then increase it. The described force is proportional to the mass and acceleration with which the car is moving. Accordingly, the more you load your car and start faster from traffic lights, the more resistance you will have to overcome.
- The force of resistance to upward movement. This force is essential when the car has to move in mountainous terrain with frequent ups and downs, and coasting is impossible due to safety conditions.
But before a long journey, when driving at high speeds on highways is expected, factory instructions often even recommend increasing the pressure by 0.2–0.3 bar. At reasonable speeds, this will reduce tire heat, increase tire life and save some fuel. In this case, the savings will not exceed 3%. I do not advise you to increase the pressure by a large amount, because the effect of fuel economy will surpass the running gear of the car, and the car will become rigid, like a cart. Safety will also suffer, because the stability and handling of the car will be far from calculated, and simply from what you are used to.
The people in Russia live very inquisitive, distrustful and prone to experiments. Take, for example, the Germans. If there is an instruction manual for the equipment, then the German will carefully, punctually follow its recommendations. Our person, most likely, will not even read the instructions to the end. It is much more interesting for him to experiment, to touch with his hands, to come up with some kind of know-how.
Therefore, a car for our fellow citizens is a real find, with which you can show the full power of your intellect. For many years now, among motorists, such a bike has been in use that if you lower the pressure in the wheels of your car by half an atmosphere from the norm, then the smoothness of the ride will improve significantly, and if you pump the tires to the same half-atmosphere, the car will seriously save fuel .
In fact, if you drop the air pressure in the wheels by half an atmosphere, you get the following. Yes, the car will run much smoother. It will not become noticeable small potholes, cracks, and even larger bumps on the road, the car passes much easier. This is due to the fact that the tires, having lost half of the atmosphere, have become softer.
In addition, we can note the fact that the car, on a straight line, will become much faster, as well as significantly improve the response of the brakes. This effect is explained very simply - the area of contact of the tread with pavement increase, which means that the area of adhesion of the tire to the road will become larger.
However, all these pluses very quickly turn into a minus when we pay attention to the fact that fuel consumption increases. Let it be insignificant (about 2%), but still unpleasant. Seriously getting worse directional stability car. Much harder to drive the car. But this is already serious. So close to the accident. What for then to you smoothness of a course? In addition, under-inflated tires begin to wear quickly at the edges.
Well, if you pump the tires to half the atmosphere, then the car will slightly save fuel (about 1.6%), and the car's handling at low speeds will also improve somewhat. Tires brake normally, but it will become much more difficult to stay on the verge of skidding.
However, there are also serious drawbacks. Due to the fact that the area of adhesion of the tire to the road is reduced, the speed of the car is reduced and the controllability during fast driving is significantly worse, as the driver begins to “feel” the steering wheel much worse.
In addition, overinflated tires begin to react sharply to all the bumps in the roadway, turning a trip in the car into a real torture. Do you need it? Moreover, tire wear in the middle of the tread will seriously increase.
The conclusion from all of the above is quite simple - tires with a pressure deviation in one direction or another significantly worsen the consumer properties of the car, not to mention the fact that the wear of your car's rubber sharply increases. It is especially dangerous to under-inflate tires, as this is fraught with the creation of an emergency.
Therefore, using quality tires well-known manufacturers (BFGOODRICH, BRIDGESTONE, CONTINENTAL, DUNLOP, GISLAVED, GOODYEAR, KLEBER, MICHELIN, NOKIAN, PIRELLI, YOKOHAMA), maintain normal (manufacturer recommended) tire pressure for your vehicle.
***PRESS RELEASE The material is published on commercial terms.
PRESS RELEASE. The material is published on commercial terms.
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The inhabitants of Russia have an inquisitive mind, tend to distrust anything and independently conduct experiments with anything. For example, in Germany, people are not like that at all. When a technique has instructions for its use, the German will carefully study the recommendations and will follow them. A Russian citizen, in most cases, will not even read the instructions, since he prefers the experiment and his own experience, perhaps even the introduction of his own know-how.
That is why, for a Russian, a car is a godsend, using which you can prove to everyone how developed his intellect is. Not for the first year, a bike has been circulating among car owners, according to which, dropping tire pressure by half a unit can help save on fuel. In reality, if you lower the pressure in the tires by half atmospheric units, this is what happens.
That's right, the car will go a little smoother than before. But small potholes and cracks, and possibly even large irregularities on the roadway, will not be noticeable. The reason for this is that the wheels have become softer, due to the fact that they are more "deflated".
Such trips can be considered a game of Russian roulette - whether an accident happens or not, this should keep the driver in constant tension. In addition, it is a well-known fact that under reduced pressure, tires wear out much faster. This again results in an increased risk of an accident.
- There is also a reverse moment - the tire is too much inflated. This often happens when, on a cold winter morning, it is discovered that the wheels have been inflated overnight. A caring owner, of course, decides to pump them up to the required atmospheres.
- After some time, the frost on the street, one way or another, will pass, it will get warmer on the street. The air that was in the tires will also warm up, increasing the pressure force in the tire. To this can be added the heating of tires from movement, and an even greater increase in internal pressure.
- An overinflated wheel will not ride, but will jump along the road, providing too hard a ride. Even if visually the road will seem even and smooth, the car will shake, vibration will appear. Any hole can lead to damage not only to the tire, but also to the disc.
Inflated tires
Here, nevertheless, it is possible to reveal the dependence of the wheels pumped to the floor of a unit of pressure and economical fuel consumption. But consumption will be reduced by only 1.6 percent. At low speed, it will seem that the car is really easier to control. But in fact, this will increase stopping distance and deterioration of the adhesion of the tire and the road, due to a decrease in the area of the contact patch of the tire. The car will try to skid, with a decrease in speed, the handling will become very bad, the “sensitivity” of the steering wheel will disappear.