What should you know about car tires?

Content:

• The quality of automobile tires
• Age of car tires
• Tire pressure
• Nitrogen instead of air?
• Tire seasonality
• Tire marking and direction
• When to change tires?
• Types of rubber wear
• Disturbance of camber-descent

Tires are one of the key parts of a car, as they connect 1 to 3 tons of rolling steel mass to the asphalt. At the same time, traction consists of 4 areas the size of an advertising booklet. Properly inflated car tires operate at a relatively low pressure, usually around 2.2 bar, to cushion the occupants while supporting the vehicle's weight. The more you inflate the tires, the harsher the ride will be.

On the contrary, if you underinflate the tires, you will get a smoother ride, more fuel consumption and overheating of the rubber. Many people drive with severely underinflated tires because they neglect maintenance and don't check tire pressures on time. The correct pressure is crucial as it ensures proper traction, safety and efficiency.

The quality of automobile tires

When buying tires, you can buy new or retreaded tires.Refurbished tires- these are old tires from which the profile was removed and a new one was glued. Youshould stay away from retreaded tires, because they are unreliable and can cost you your life. When it comes to tires, in most cases it is correct that the more you pay and the more reputable the brand, the better they perform. That's why the more expensive the cars driving past you on the street, the more likely their tires are from industry leaders likeMichelin,Continental,Goodyear,Pirelli,Nokianor Bridgestone.

Age of car tires

Rubber tires break down over time.After 5-6 years, the rubber hardens, and the wheel can no longer be reliable and safe. This is especially true in hot and sunny climates. Some people even protect their tires from the sun and external influences with the help of special boxes on wheels. Sports cars and supercars often don't get a new set of tires in time, and when buying used cars you'll often find that sellers haven't changed the tires in over 6 years, which in my opinion is irresponsible for sports cars or any car in general.

WhenPaul Walkerdied in a 2013 car accident in his Porsche Carrera GT, the investigation concluded that the car was fitted with old tires that did not provide enough traction. (Another factor was speeding). The year and month of manufacture are engraved on the sidewall of your tire. ItA 4-digit code that indicates the week of production and the year.

Tire pressure

As already mentioned, improperly inflated tires can wear unevenly, wear out faster and worsen fuel economy. Improper tire pressure can even be a serious hazard, as this example showsChevrolet Corvair. During the production of this car, the pressure had to differ by 0.7 bar between the front (1.25 bar) and rear (1.93 bar) tires due to the heavy weight shift of the rear of the car and the rear air-cooled engine.

The Corvair will feel unstable at speed if the front and rear pressures are the same. And this greatly increases the risk of losing control of the car during an emergency situation or a sharp maneuver. When in 1965 Ralph Nadars published "Dangerous at any speed", which drew attention to automotive and safety issues, it discussed the serious risk of an accident due to improper tire pressure.

Air, which is under pressure in the tires,reacts to temperature changes. Gases expand with heat and contract with cold, which is why your car's tire pressure warning light usually comes on when it's cold. If you have an older car, you likely won't have a tire pressure warning light and you'll have to check the pressure manually.It is recommended to carry out an inspection at least once every 3 months.

Tire pressure is measured in PSI, bars or kPa (kiloPascals). 100 kPa is equal to 1 bar. Car manufacturers often use this unit because it's easier to give accurate pressure numbers because it doesn't have to be broken down into fractions. Also, it is a more scientific unit for measuring pressure, like kW for horse power. The vehicle's recommended tire pressure should be printed on the door sill, inside the fuel filler flap or in the owner's manual. First, check the dimensions of the tire and the maximum allowable pressure for them (written on the tire itself) so as not to overdo it. Thencheck fuel tank door/hatch sills for proper air pressureaccording to your tire size and vehicle load.

Nitrogen instead of air?

Car tires are usually filled with compressed air. Air is 78% nitrogen and just under 21% oxygen, with the rest being water vapor, CO2, and small concentrations of inert gases such as neon and argon. All tires lose pressure over time as gases seep through the rubber.

One measure to slow down deflation is to fill the tires with pure nitrogen. Nitrogen flows 40% slower than regular air, resulting in a more stable tire pressure over a longer period of time. Pure nitrogen better maintains the required tire pressure. Oxygen also reacts with the rubber by penetrating it, leading to a process of rubber degradation over time. This is especially important for classic cars, as they are rarely driven and the tires stay on the car much longer. If the tires are filled with nitrogen, this can usually be seen by the green valve stem caps.

Tire seasonality

There are three main categories of car tires:

• winter;
• summer;
• all-season.

The main difference between them is the composition of the rubber. Winter tires are made of softer rubber, and they grip the road better in cold weather. Contrary to popular belief,winter tires do not necessarily have to have a different profile. It depends on the summer and winter tire model. They can have tiny rubber grooves ("slots") in the profile channels for better grip and snow removal. In addition, the tread pattern can be rougher and more textured for better grip on snowy and dirty roads. But otherwise, they are simply softer compared to summer or all-season tires.Winter and summer tires are distinguished not by the pattern of the tread, but by the symbol on the sidewall.

Winter tires can be identified by one of two symbols on the sidewall.M+S symbol and snowflake mountain symbolas three peaks are industry standards. If none of these symbols are displayed, the tires are not suitable for winter use. In climatic zones where snow falls in winter, tires should be changed in autumn and spring. In some European countries, you can be fined if you drive on summer tires during the winter months. If you don't want to do that, you can just order winter tires from a car shop and drive them summer and winter. Howeverwinter tires will wear out faster in the summer due to the softer composition of the rubber. Winter tires are often used in street racing because they grip the road better.

As for all-season tires, such wheels are not recommended for use either in winter or in summer. Why? They are softer than summer tires (must be soft for proper operation in winter), but harder than winter tires (so as not to wear out in a season or two in the warm season). Buying "all-season", you will get poor grip in winter on icy asphalt and excessively soft rubber in summer, which will "melt" on the road much faster than specially designed summer rubber.

Tire marking and direction

The set of letters and numbers on the sidewalls of tires may seem complicated, but everything is quite simple if you understand what you are looking at. Mostlythey give you information about size and speed limits. Only a few tire sizes can be used on your rims. If you don't choose the right tire, you also run the risk of your speedometer no longer showing accurate readings. If you have a larger tire, your speedometer will show a slower speed than you are actually going.

In addition, choosing this or that rubber,you should pay attention to whether the rubber has a direction (Rotation). It is indicated on the side of each wheel with an inscription and an arrow indicating the correct direction of rotation. Such tires should be installed only in the correct direction due to their design features.

Be sure to consult your vehicle's owner's manual to select the correct tire size.

When to change tires?

Tires should be replaced if the profile is less than 2 mm. You can measure the thickness of the tread with a caliper or do the coin test. The coin test is a simple technique that will help you determine the need for tire replacement. Just turn it upside down and insert it between the tire treads. If you live in Europe, you can use the coin inone euro. The width of the golden edge of the coin is exactly 3 millimeters. Insert a coin into the tire profile. If the gold edge is closed, you still have at least 3 millimeters of profile. If you see a little gold rim, it's time to replace the tires.

New rubber sold in the USA and Europe is a must haveindicators built into the tread pattern, which run across the tire tread and are called wear strips. When tires are worn to the point where the wear strips are at the same height as the tread, they no longer meet the minimum tread depth requirements and the tire must be replaced.

Types of rubber wear

If the tires are incorrectly aligned (unbalanced), they wear out faster, overheat and begin to wear out in one place. This can also be a potential hazard. In addition, they wear unevenly relative to each other, which entails higher costs for a new complete set of tires.

This can be expensive in the long run, so the pattern of wear and tear must be monitored.The most common sign of misalignment is a violation of tire balancing. If the wheels are not balanced correctly, the rubber wears on the inner or outer edge. The picture above shows a classic example of incorrect wheel alignment.

Disturbance of camber-descent

Another common form of tire wear in the event of suspension failure is camber-climbing.Camber-descentis the vertical angle of inclination of the wheel in relation to the ground. Ideally, it should be 90 degrees. Camber-toeing usually results in uneven tire wear, as shown in the figure below. Here you can clearly see the angle of wear or increased wear along the profile from left to right.

Summarizing, it is safe to say that with proper suspension setup and operating mode, your new rubber set will last for more than one season. And buying all-season tires is not the optimal solution, while it will be correct to buy two sets - winter for winter and summer for summer. That way, it will last longer, and it will "work" better. Any automotive expert or enthusiast will tell you this. After reading these recommendations and explanations, you learned what is needed for the correct selection and maintenance of tires on your car.