Tire pressure

Inflation pressure is a major factor in the safety and life of your tires. Insufficient pressure or over-inflated tires can adversely affect their performance.

Almost every motorist knows how important it is to maintain the correct tire pressure. This also affects fuel consumption. and driving behavior and tire performance. It's no secret that with the right pressure, tire life increases. The driver on the road feels comfortable and safe. But does everyone apply this knowledge in practice?

How often do you check the pressure in your car tires? Do you know what causes too much or too little pressure? The correct pressure will help to avoid various deformations of the tread and the tire as a whole. The consumer qualities of the tire will be preserved with all the parameters developed by the manufacturer.

It is believed that tire pressure should be checked at least once every two weeks. But even this is often not enough. After all, pressure can be influenced by many factors: the accuracy of the driver, the design of the tire, the temperature difference.

In summer, for example, it is advisable to check tire pressure every 200-300 km. Know that every 10°C increase or decrease in temperature results in a 1 psi change in tire pressure.

You also need to check your tires after any long parking. Moreover, to do this not "by eye", and not the favorite method of "kick" on the wheels. The only device that will measure pressure correctly is a pressure gauge.

How to know the correct pressure?
The vehicle manufacturer always makes pressure recommendations. This information can be found either in the instruction manual or on the plate.

The table is usually located on the door pillar, in the glove compartment or in the gas tank flap (on the inside). The table shows tire pressure data and maximum load.

How to measure pressure correctly?
The pressure is checked by a car compressor or a stationary compressor at a gas station or at a tire shop. Make sure the tire is "cold" before checking.

It is impossible to lower the internal pressure in "hot" tires. And remember, when driving, the tire heats up, therefore, the pressure increases.

Cons of insufficient pressure.

1. Under-inflated tire uneven pressure is created on the canvas, so the adhesion properties deteriorate. The result is rapid tire wear.
2. Insufficient pressure increases the amplitude of deformations, increases heat. Lost energy, increased fuel consumption.
3. A 20% reduction in blood pressure will result in Reduce tire life by 30%.
4. An under-inflated tire is dangerous. When moving, it heats up a lot, this destroys its frame. The tire may disassemble or burst.

Disadvantages of overpressure
1. An over-inflated tire becomes hard and lighter. rolls, but at the same time loses grip. If the car gets into a hole, not only the tire will be damaged. The load on the body and suspension will increase.
2. Hard tires are uncomfortable because they transmit more noise in the car.

In what cases is it possible to reduce or increase pressure?
Sometimes it happens that a decrease or increase in pressure relative to the factory recommendations is beneficial to the car. It's about the contact patch. The lower the pressure in the tires, the larger, respectively, the contact patch. And vice versa. In what cases can it help?
1. Movement on soft ground (clay, mud, etc.). If you reduce pressure by a quarter, the contact patch will increase by 1.3 times, or even more. This will give less ground pressure.
2. Driving on wet roads. Increasing tire pressure will reduce the contact patch. The risk of hydroplaning will be reduced. Note that for modern tires this rule is irrelevant. Water drainage is already structurally incorporated in them.
Increasing the pressure will also lead to improved controllability, lower fuel consumption. But you should not get carried away, because with all the pluses you will get a significant minus - the probability of an explosion on the tire will increase.
3. Movement on rocky ground. By increasing the pressure, you reduce the risk of sidewall damage.
The main thing is that you do not forget to return the tire pressure to normal after passing a difficult section.

Regularly monitor the tire pressure, maintain the pressure at a normal level (see photo). The pressure is checked on cold tires, after a certain time after the trip. It is forbidden to reduce the pressure in hot tires to the pressure set for cold tires, as when they cool down, the pressure will drop and become lower than normal.

Pay attention to any signs of abnormal tire wear. Watch the tire tread pattern. Signs of uneven tread wear such as angular tread wear, patchy tread wear and increased wear on one side of the wheel indicate misalignment of the front wheels and/or balance. If any of these signs of wear are found, find the cause and repair immediately.

Excessive tire pressure causes accelerated wear of the middle part of the tread, which reduces traction, reduces the damping effect of the suspension and increases the risk of tire blowout.

Regularly check the tires for cuts or bulges, especially on the side surfaces. Remove stones or sharp objects stuck in the tread before they penetrate the tire and cause a sudden pressure drop. Periodically remove the wheels and clean the outer and inner surfaces of the disc from dirt. Watch for corrosion, rust or other deposits on the rims. Light alloy wheels are quickly damaged when hitting a curb while parking, and steel rims also leave deflections and dents. In order to prevent increased wear of not only tires, steering and suspension parts, it is necessary to monitor the wheel balance. Signs of wheel imbalance are usually the vibration of the car body (at a speed of about 90 km / h), although in most cases the vibration is felt through the steering wheel. In turn, it should be borne in mind that wear or damage to steering and suspension parts can cause increased tire wear. Tire wear is highly dependent on driving style and accelerates during heavy braking and acceleration, when cornering at high speed. Swapping the wheels allows for more even tire wear.

1. The tires that the manufacturer equips the vehicle with are equipped with a protective band (B), which becomes visible when the residual tread depth reaches less than 1.6 mm. The location of the protector is indicated by a triangular mark A.

2. Checking the tread depth with a gauge.

3. Check tire pressure with a pressure gauge. It is not allowed to check the pressure in a hot tire.

Cold tire pressure

The pressure in the tires that the vehicle is equipped with is indicated on the label affixed to the gas tank filler door from the inside.

To check the wheels on an Opel Astra N car, you will need: a pressure gauge, a pump, a caliper.

USEFUL TIPS
Periodically check the air pressure in the tires (Table 4.2, Appendix 4). Too much or too little tire pressure can cause premature tire wear, poor vehicle handling and stability, which can lead to an accident.

We recommend using a foot pump with a built-in pressure gauge. In order for the tires to wear out evenly, rearrange the wheels every 10,000 km in accordance with the diagram in Fig. 4.1.
In addition, after every 20,000 km, balance the wheels and check the angles of the front wheels (camber, convergence). To do this, contact a specialized workshop or car service with special equipment and stands.

NOTE

On the inside of the fuel tank filler cap there is a sticker that indicates the air pressure in the tires at various loadings of the Opel Astra N car.

Rice. 4.1. Scheme of rearrangement of wheels on a car Opel Astra N

WARNINGS
Carry out all wheel repair work in specialized workshops. Check that the wheel is balanced after repair.
Using tires with worn tread can lead to accidents and accidents.

1. Open the fuel tank filler cap and remove the wrench from the holder on its loop to unscrew the wheel valve caps.

You will need: pressure gauge, pump, caliper.

Regularly check the air pressure in the tires (Table 1). Maintaining nominal air pressure in tires provides the best combination of tire durability, handling and vehicle comfort.

Every time you check the air pressure in the tires, carefully inspect them for mechanical damage to the tread and sidewalls, small stones, nails stuck in the tread, signs of severe tread wear. Pay special attention to the following tire defects:

• local swelling or bulging of the carcass in the tread area or on the sidewalls. A tire with a similar defect must be replaced;
• cuts, cracks or delamination of the sidewall frame. Replace the tire if the carcass cord is exposed.

In order for the tires to wear out evenly, rearrange the wheels every 10,000 km in accordance with the diagram in Fig. one.

In addition, every 20,000 km, balance the wheels and check the alignment of the front wheels. To do this, contact a specialized workshop.

Rice. 1. Scheme of rearrangement of wheels

Table 1. Air pressure in tires, kgf / cm 2

Tire size	3 people in cabin and cargo (comfort)		3 people in the cabin and cargo (savings)		Full load
	Front wheels	rear wheels	Front wheels	rear wheels	Front wheels	rear wheels
205/60 R16, 215/60 R16, 215/50 R17, 225/45 R18, 235/40 R19	2,2	2,2	2,6	2,4	2,3	2,7
T115/70 R16	4,2	4,2	4,2	4,2	4,2	4,2

On the central pillar of the body in the opening of the driver's door there is a sticker that indicates the air pressure in the tires at various vehicle loads.

1. Unscrew the cap from the valve.

2. Check tire pressure. To do this, reset the pressure gauge to zero by pressing a special button on the pressure gauge housing ...

3. ... connect a pressure gauge to the valve and press the valve spool with the tip of the pressure gauge.

NOTE

Air pressure should only be checked with cold tires. Tires can be considered cold if at least three hours have passed since the car was stopped or if after a long parking of the car you have driven a distance of no more than 1 km. After the car has run a distance of several kilometers, the tires will have time to heat up and the air pressure in them will increase by 30–40 kPa (0.3–0.4 kgf / cm 2) compared to the cold state. This is not a malfunction. Do not reduce the air pressure in warm tires to bring it to the nominal value that is set for cold tires. Otherwise, the tires will run at reduced air pressure.

4. If the pressure is less than required, connect the tip of the pump hose to the valve and pump air, controlling the pressure on the pressure gauge on the pump.

5. If the pressure is more than required, press the special protrusion of the pressure gauge on the tip of the spool and release the air from the tire. Measure the pressure with a manometer. By repeating these operations, bring the pressure to normal.

NOTE

Remember to check the air pressure in the spare tire at the same time as checking the pressure in the other tires.

6. If you notice that the air pressure in the tires is constantly dropping, try tightening the spool with a cap with a key.