1. tire selection and precautions

1. According to the model or specification

Priority should be given to the original tires of the vehicle. The specifications of the original tires are the ones that best match the speed of the car and the maximum load of the car. Therefore, in theory, priority should be given when replacing tires.

Example: 185/70R1486H

185: Tread width (mm)

70: flat ratio (tire height ÷ tire width)(70 refers to 70%)

R:R means that the tire is a radial tire, and there is also a rare bias tire, which is represented by "D.

14: Diameter of steel ring (inch)

86: Load index (indicating that the corresponding maximum load is 530kg)

H: Speed code (indicating that the maximum safe speed is 210 km/h)

2. Precautions

1), choose tires as far as possible to consider the original

2) The second thing to pay attention to is the tire pattern. In addition to the aesthetic effect, the pattern on the car tire also has a great impact on the performance of the tire. Need to cross-country and long-distance car, you can choose a large block pattern.

3) If you are not satisfied with the original handling of the vehicle, you can consider replacing tires with a lower aspect ratio. For many models, one of the most effective ways to improve the appearance and handling performance of the vehicle is to replace tires with a lower aspect ratio.

4) When choosing tires, be careful not to mix different types of tires. For example, put tires that are more suitable for off-road vehicles together with tires of ordinary cars, or use directional sports car tires. Mixed with general tires.

5) Try to avoid retreading tires in the purchase. At present, some small repair shops on the street often sell some retreading tires as shoddy ones. Consumers must pay attention to the purchase. The method of identifying refurbished tires is very simple: the most common is to observe the color and luster of the tires. The color and luster of the tires after retreading are relatively dim, so don't buy such tires blindly.

6) In recent years, the development trend of foreign car tires is to use more and more tires with large width, large inner diameter and low aspect ratio. At present, domestic cars use more tires with small width, small inner diameter and high aspect ratio. Tires with high aspect ratio have long sidewalls and strong cushioning capacity, and are relatively comfortable, but they have a poor feeling on the road and weak lateral resistance when turning. Conversely, tires with low aspect ratios and large inner diameters have short sidewalls and wide treads. Therefore, the ground contact area is large, the tire can withstand high pressure, the response to the road surface is very sensitive, and the lateral resistance when turning is strong, which greatly enhances the handling of the vehicle. However, the wider the section, the greater the friction between the tire and the ground and the stronger the grip, but it generally increases fuel consumption.

How to distinguish between 2. bias tires, radial tires and tubeless tires

Simply put, bias tires are nylon tires. Radial tires are steel tires. Tubeless tires have no inner tube. Both bias tires and radial tires have vacuum tires and non-vacuum tires.

1. bias tire

Bias tires, also known as ordinary structure tires, are old-fashioned structure tires. The outer tire is composed of a tread, a ply (carcass), a buffer layer and a bead. The ply is the skeleton of the outer tire, which is used to maintain the shape and size of the outer tire. It is usually made of double-layer rubber (cord).

The bias tire is a kind of tire commonly used in modern automobiles. Although it has been used for a long time, has a wide range of use, and has a certain foundation in production technology, due to its unreasonable structure, it has affected its development and will gradually be meridianized. Replaced by the tide. This kind of tire has good longitudinal rigidity and is suitable for medium-speed driving on ordinary roads.

2. Radial tire

The cords of radial tires are not arranged across each other, but are close to parallel to the tire section, like the earth meridian arrangement. The cord angle is small, generally 0 °, and there is no maintenance intersection between the carcass cords. During the driving process, the stress around the crown increases, which will cause circumferential stretching and radial cracks in the carcass. The belt design of radial tires is very important. It must have good rigidity. Multiple layers of fiber materials with large angles, high strength and difficult to stretch, such as steel wire or glass fiber, can be used.

The advantages of radial tires:

1) Large ground contact area, good adhesion performance, small tread slip, and low unit pressure on the ground, so the rolling resistance is small and the service life is long.

2) The tire crown is thick and has a hard belt layer, which is not easy to puncture; the deformation is small when driving, which can reduce fuel consumption by 3% ~ 8%.

3) Because the number of plies is small and the sidewall is thin, its radial elasticity is large, its cushioning performance is good, and its load capacity is large.

4) Good heat dissipation performance, suitable for high temperature and high speed driving. Light weight, low rolling resistance, saving fuel.

5), radial tire side thin, so relatively soft, good elasticity, reduce shock and noise.

the shortcomings of radial tires:

Because the sidewall is thin and the crown is thick, it is easy to produce cracks in the transition zone between the sidewall and the sidewall. The large side deformation leads to poor lateral stability of the car, high manufacturing technology requirements and high cost.

3. Vacuum tire

Vacuum tires are tubeless pneumatic tires, also known as "low-pressure tires" and "inflatable tires". In recent years, vacuum tires have been widely used in motorcycles, cars, buses and trucks. Vacuum tires have high elasticity and wear resistance, and have good adhesion and heat dissipation performance. In particular, all-steel radial vacuum tires, due to their economic durability, are promoted by the National Economic Commission and the National Tire Association to the logistics and transportation industry.

The advantages of vacuum tires:

1) Puncture resistance = safety-the surface of the vacuum tire is a layer of high-quality rubber. After inflation, the external tension increases and a certain pressure is formed on the inner surface, which improves the self-sealing ability of the break. Once it is punctured, it is not like ordinary tires. All the gas is released in an instant, and it will last for a certain period of time, ensuring the safety of high-speed driving.

2) Super wear-resistant = save money-vacuum tire rims have a larger diameter than ordinary rims and will not be affected by the heat of the brake drum during driving. Since there is no inner tube and lining belt, the tire and the wheel rim are sealed as a whole. When the vehicle is running at high speed, the high temperature generated by the friction between the tire and the road will be directly dissipated inside (hot air) through the steel ring to quickly reduce the tire temperature, thereby extending the tire The service life.

3) Low fuel consumption = making money-vacuum tires are flat tires in metric units 315/80R22.5,295/80R22.5,275/70R22.5, and the tire crown angle is zero, so the adhesion is strong. It can maintain good driving stability and low friction, which is beneficial to shock absorption and increase vehicle speed. The positioning of the belt speed layer is high, the radial runout of the wheel is small, and the resistance is small. This reduces fuel by 3%.

Trucks and trucks using tubeless tires have higher wear resistance, safety, comfort and stability than ordinary tires.

Disadvantages of vacuum tires:

1), not pressure, not suitable for overload, vacuum tire wear-resistant but not pressure, but with the implementation of the national load limit weight limit policy, perhaps the frequency of use of vacuum tires will become higher.

2) Tubeless tires have good adaptability to asphalt and cement roads, and can maintain strong adhesion even if there is water on the road surface, and have good stability. But on the soil pavement, especially muddy road adhesion is small, poor stability. It is not advisable to drive on dirt roads in the suburbs.

3) Repair is more troublesome and costly. Once the vacuum tire punctures and leaks, it is more troublesome to repair. The cost of repairing the vacuum tire once is much higher than that of the tire with inner tube.

3. tire maintenance should start from what aspects

1. Tire pressure

Tire pressure affects the service life of tires. If the tire pressure is too high, the tire will stretch and deform, and the elasticity of the carcass will decrease, which will increase the load of the car during driving. Too low tire pressure increases the ground contact area of the tire, causes abnormal heating of the tire, and accelerates the wear of the sidewall. Therefore, regular inspection of tire pressure can better ensure driving safety.

2. Tire tread depth

Generally speaking, the thickness of the tread pattern should be greater than 1.6mm. If the tire pattern is seriously worn, the tire should be replaced in time. Tread cracks are an important sign of tire aging. During daily vehicle maintenance, you must pay attention to observe whether there are cracks in the tire.

3. Small stones in the tire seam

When a car is driving, it is inevitable that there will be small stones stuck in the tire pattern. Small stones are stuck in the tires, and the vehicle will make a noise when driving, which is harsh and unpleasant. In addition, the pebble is a tire killer, will scratch the tire, causing traffic safety threats.

4. Drum

The protrusion on the surface of the tire indicates that the tire should be replaced. If you use a bulging tire for a long time, there is a great possibility of sudden bursting in areas with insufficient strength on the tread. Such tires must be replaced immediately.