Introduction to commonly used tires for automobiles

 One day in October 1887, British veterinarian John Dunlop leaned against the entrance of his veterinary clinic, watching his youngest son play on a small tricycle on the cobblestone street. Although my son struggled to pedal, the tricycle with solid rubber wheels still couldn't walk fast, and driving on cobblestone roads caused him a lot of pain. As he felt sorry for his son, he thought of the carriage he had taken out to practice medicine, with its hard and solid rubber wheels pressed against the rocky road surface, causing him to suffer from bumps. If soft materials can be used to wrap the wheels, it will definitely make cycling and riding comfortable. As soon as he thought of it, he started searching for soft materials.
Perhaps due to the need to come into contact with rubber tubes during medical practice, John Dunlop thought of rubber tubes. He found a rubber hose for watering flowers in the garden, cut it and tied it to a wooden disc with a diameter of 94cm using a cloth strip. He then sealed one end of the rubber hose with glue, found a tube to inflate the football, and finally sealed it.
Later, after conducting various performance tests, he found that the inflatable wheel was simply superior to the solid rubber wheel, which made him very satisfied. Therefore, on December 7, 1888, he obtained the invention patent for the inflatable tire. Subsequently, he quickly partnered with others to establish a company and began producing inflatable bicycle tires. Dunlop's bicycle tire factory has developed rapidly and has opened factories in Ireland and the UK. However, Dunlop's original intention of inventing pneumatic tires was not to use them on cars, but on bicycles. It was not until 1895 that the French Michelin brothers realized the use of pneumatic tires on cars. (Later, Dunlop Company also produced tires for automobiles, and now its company has been acquired by the Sumitomo Corporation of Japan.)
Tires can be divided into off-road tires AT/MT, explosion-proof tires, anti puncture tires, and snow tires according to their different functions. According to the usage scenario, it can be divided into summer tires, four season tires, and winter tires. We must choose the appropriate type of tires when driving on different terrains.
Summer tires
In summer, the tire walls are thicker and the tread is shallower. The continuous vertical grooves improve straight-line stability, and the large contact area on both sides provides better grip and road feedback during cornering, but also reduces comfort. This tire is suitable for roads with high temperatures, both dry and wet. In winter, when the temperature is below 7 ℃, its texture will become harder, and its grip will deteriorate. It can be used for longer braking distances on icy and snowy roads.
Four season tires
It is the tire we use in our daily lives, a universal tire that is suitable for various scenarios and can be considered a compromise choice. It can maintain good grip and drainage performance at low temperatures. It is the most widely used type of tire. (The data in the following figure is sourced from Dongchedi)
Winter tires
Suitable for winter icy and snowy weather, the tires have been optimized specifically for harsh snow conditions. They use a rubber blend that remains soft and has better grip even at temperatures below 7 ℃, with deeper tread patterns. This also means that driving on normal cement roads causes more severe wear and tear. Therefore, when the temperature warms up, it is necessary to replace them with summer or all season tires.
Off road tires
Off road tires generally include road tires, all terrain tires, mud tires, etc. In addition, there are rare but professional types of off-road tires, such as snow tires, rainforest tires, climbing tires, desert tires, etc. Off road tires are usually used on mountain roads, muddy roads, and other road surfaces. They have the following advantages: their tread design is thicker (thicker tire walls), which improves grip and off-road performance on bumpy roads; At the same time, it reduces the possibility of groove blockage and improves handling performance.
Anti puncture tire
As the name suggests, anti puncture tire refers to a tire accidentally punctured by rivets, which will automatically repair and prevent tire deflation, thereby stabilizing tire pressure. Anti puncture tires have thicker walls and heavier weight compared to regular tires. This will bring significant tire noise to the entire vehicle, and the shock absorption of the tires is also poor. In fact, it is more bumpy and noisy to ride than other tires, and the tire grip is also poor, especially on wet and slippery roads in rainy days. In addition, the cost of anti puncture tires is also higher, but for car manufacturers, they eliminate the cost of spare tires.
Explosion proof tire
In 2001, the fourth generation BMW 7 Series was the first to be equipped with Run Stability Control (RSC) tires (also known as "run flat tires"). It consists of specially designed tires and tire pressure monitors. Once the tire pressure starts to decrease, RSC tires immediately issue a warning to the driver. Even if the tire pressure drops to 0, RSC tires can still ensure that the tires are safely fixed on the wheel restraint, allowing the vehicle to continue driving at a maximum speed of 80km/h for 50-250km. In this way, spare tires, repair kits, and jacks no longer need to be placed on the vehicle, and drivers do not need to personally replace tires on the roadside.
RSC tires have relatively hard sidewalls that can support the tire to continue driving even at zero pressure. It also has a specially designed wheel facing convex peak, which can prevent the tire from detaching from the wheel rim after a sudden drop in pressure.
RSC tires monitor the air pressure of each tire by constantly comparing their rotational speeds (the lower the tire pressure, the higher the rotational speed). When the vehicle speed exceeds 15km/h and the tire pressure drops by more than 30%, if the speed of a tire changes irregularly, the system will alert the driver through warning lights and sound signals.
Furthermore, let's introduce the meaning represented by tire tread. Firstly, let's take a tire specification as an example: 195/55R1585V
195 represents the cross-sectional width (W). The tire section width refers to the maximum distance between the two outer sides of a tire after being inflated according to regulations. It is generally divided in units of 5mm, but the tolerance for the new tire section width is 63%.
55 stands for Flatness Ratio (AR). Flatness ratio is a data of a tire, which refers to the percentage of the tire's cross-sectional height to its maximum cross-sectional width. Simply put, it is the tire's aspect ratio.
R represents the tire structure, namely radial tires. Different from bias tires, arch tires, pressure regulating tires, etc. The international code for radial tires is "R", commonly known as "steel wire tires"
15 represents the diameter (inches) that is compatible with the wheel hub.
8 represents the load index, also known as the load capacity index. The load index refers to the value represented by the maximum load that a tire can carry under specified conditions at its maximum air pressure.
V represents the speed level. The speed rating indicates the maximum speed at which a tire can carry a specified load under specified conditions. English letters are used on the walls of different tires to indicate the speed rating of the tire. Representing the certified speed level of tires from 4.8 kilometers per hour to 300 kilometers per hour.
In addition, the tire surface will also be marked with information such as production date and wear resistance index.
As shown in the above figure, the production date of a tire is usually represented by the four digits behind the "DOT" symbol on the tire side. Among these four digits, the first two represent the year of production, and the last two represent the week of production in that year. Therefore, the production date of tire 4920 is the 49th week of 2020, approximately between the end of November and the beginning of December 2020.
The development of automobiles has lasted for over a hundred years, and well-known tire brands both domestically and internationally are dazzling.
Foreign brands mainly include Michelin (French brand), Bridgestone (Japanese brand), Goodyear (American brand), Michelin (German brand), Dunlop (Japanese brand), Pirelli (Italian brand), Hankook (Korean brand), Yokohama (Japanese brand), Sumitomo Rubber (Japanese brand), and Nokian Tire (Finnish brand)
Domestic brands mainly include Chaoyang, Zhengxin, Triangle, Double Star, Linglong, Huili, Magis, Haida, Wanli, Fengshen, Shuangqian, Chengshan, Qianjin, Huanan, and so on.