As the most standard and stringent testing organization, IIHS in the United States has always believed that knee airbags are one of the most useless configurations.
The airbag configuration of high-cost equipment should have helped a lot to improve safety, but the knee airbag is really an exception, installing airbags on the original narrow leg space, although it will not affect the action during daily use, but it will indeed affect the leg movement space after bursting.
In hundreds of test trials done by IIHS, the knee balloon only reduced the risk of injury by about 0.5%.
Obviously, this is not a very cost-effective data, if only to increase the safety factor of the trace amount is not harmful, but the presence of knee air bags will also adversely affect the legs.
One reason is that the knee air bags are too close to the legs, and the other reason is that the leg movement space is not large.
Are safety configurations, some configurations because the cost is very low but get the greatest benefits, such as three-point seat belt, the cost is very low but the safety of the improvement is very large, and then such as the front airbag, can also be exchanged for a higher lifting factor.
Other safety configurations also have good results, such as ABS, ESP, active braking these low-cost but very obvious configurations, the help brought by the driving process is self-evident, and these configurations almost do not have a bad effect, recognized praise configuration.
According to the cost analysis, the cost of airbags is much higher than others, and the cost of knee airbags is not low, but according to the data analysis of IIHS, the high cost only increases the safety factor by 0.5%, and there is also the possibility of reducing the leg activity space and accidentally injuring the leg, so from a rational point of view, such a configuration is not of great significance.
Some people say that I can not use it, but you can't do without it, which is a typical double-standard statement.
The enterprise installed an automatic start and stop for you, you say no, some configurations are recognized as chicken rib configuration, but the airbag with "safety" is considered a completely trustworthy configuration, but this is not the case.
If the company will calculate, the cost of the saved airbags will be evenly shared on the steel, which can be exchanged for better body rigidity, even if this improvement is minimal, but the benefit must be better than the knee airbag, or replaced by a larger side air curtain, which is also the most direct effect.
The role of air bags is also divided into three, six and nine.
The side of the head air curtain and the side airbag is absolutely more important, the side protection performance is weak, while the head is closer to the side glass, the collision of the head damage to the head is larger, in addition, the airbag can not be a good left and right constraint members.
The safety improvement brought about by the side airbag and side air curtain is obvious.
The second is the front double airbag, because the seat belt constraint and the front and rear activity space is larger, so compared to the side airbag, the front double air bag with the seat belt, the same can achieve a better safety factor.
Compared with the airbags in these two directions, the knee airbags are more like auxiliary configurations, which are indeed better, but the equipment cost is higher and the safety improvement is really not big, and it has not been recognized by some enterprises.