First of all, we must correct a wrong concept, that is, the name of this kind of tire is actually called "run-flat tire" or "low-pressure continuous tire". There is no meaning of "explosion-proof tire" in the international title, but so far we have not heard of any kind of tire that is "explosion-proof", which is actually seriously misleading by dealers and advertisements. So what are the advantages of this run-flat tire?
The so-called explosion-proof tire used by BMW can't prevent puncture or air leakage. The key lies in the hard sidewall of this tire. We know that when the tire has no air pressure, the vehicle will lose its balance immediately, and the tire will suddenly leave the hub like a pool of mud, relying only on the hub to maintain its balance. The advantage of the so-called explosion-proof tire is that it can keep the tire from leaving the hub and still give the vehicle enough support by relying on the solid and hard sidewall. Therefore, it only works when the tire loses pressure. If it is a flat tire, such as scraping the tire wall with a hard-pointed tool, it has no effect at all. It can be understood that the so-called "explosion-proof" is actually a hype. It is ridiculous to think that a flat tire can be avoided by relying on only one tire. Moreover, it is also clear from the theoretical data of the manufacturer that under the condition of zero tire pressure, you can continue to drive 250KM at a speed of 80 km/h, that is to say, if you drive at a speed of 150KM/H, you still can't guarantee safety. How many cases are there when the high-speed pressure loss is below 80? Now, as a low flat tire, the sidewall will be strengthened to a great extent than ordinary tires. In addition, a large wheel hub of 17 inch or more can generally control the vehicle under the condition of low-speed pressure loss. Therefore, the explosion-proof tire is just an ordinary tire, and the sidewall is hard.
Hard sidewall has advantages and disadvantages. The most obvious change brought by the hard sidewall is the decrease of ride comfort. Secondly, it is quite difficult to dismantle an "explosion-proof" tire with the current equipment and technical level of domestic tire shops. Because the sidewall is too hard, it is not only necessary to pry it open with a crowbar, but also inevitable to hang the hub on most tire tensioners, even in 4S shops, not to mention roadside shops. Although it is theoretically possible to continue driving for 250KM without tire pressure, will there be a BMW 4S shop or tire shop that can flatten the tires within 250KM? The feasibility of this data remains to be studied. There are already many examples. The owner of the tire lost pressure and asked the 4S shop for help. 4S said that he could continue to walk with a flat tire. The owner reluctantly drove to the 4S shop, but after driving for dozens of kilometers, he found that the wheel hub was broken. It can be seen that the theoretical value of tire continuation may only be the propaganda of manufacturers.
As can be seen from the front, it is an indisputable fact that "explosion-proof" tires are not explosion-proof, and this kind of tires has more shortcomings. First, the price. In foreign countries, an explosion-proof tire is only 65,438+00% more expensive than ordinary tires of the same model. However, the domestic 4S uses this dispensable function to sit on the ground and start the price. A horse brand csc2 SSR generally sells for more than 3,000, or even more than 4,800, and many unsuspecting consumers can only be slaughtered. In fact, as far as this kind of horse brand csc2 tire itself is concerned, the driving feeling, handling, wet performance and comfort are at the lower and middle level among the same level tires. And many big-name tires, such as Deng Lupu's SPORT MAXX and Michelin PS2, are far ahead in all kinds of achievements, but their prices are much lower, only about 65,438+10,000 yuan. As for the problem that many people consider replacing ordinary tires with spare ones, it is actually a misunderstanding. First of all, even if the tire is "explosion-proof", if the tire really loses pressure completely, do you really dare to continue running? Secondly, the tires of this grade are all vacuum low-pressure tires. When nails and other small things cause "slow exhaust", you can drive at a low speed for a while and go to the nearest tire shop for repair. In other words, a run-flat tire without a spare tire is even more troublesome than ordinary tires, because not only do you have to find a tire shop, but you may not find a tire shop that can pull out your tires. Ordinary tires do not have this problem, so it can be seen that "explosion-proof" tires are in great trouble in China.