Air bag did not deploy. Setting still at a red light and hit from the back a 55 mph and knocked into the car in front of me. Totaled my GL. I was told that the Mercedes Air bag would not deploy if you are not moving. Is this true?
Interesting question, though I suspect there are a lot of variables programmed into the system. In this scenario you may have been fortunate they did not deploy.
Airbags are designed to deploy in a hard front hit. The headrest protects you in a rear hit… which they did. You bounced into the car in front. Not a hard enough hit to deploy the bags. Plus you didn’t need them to save your life because you are here posting the question.
Your MB performed as designed.
The rear impact drove the OP’s head into the head restraint, and it almost surely prevented serious head and neck injury. The car that ran into him should have had its airbags deploy because it was subjected to a frontal impact.
In the aftermath of the collision, did the OP notice whether the airbag(s) in the other car had deployed? If they did deploy, then that car’s safety systems worked as they were designed to work, as did the safety systems in the OP’s car.
Did you suffer injuries from hitting the steering wheel?
Out of curiosity, what was the other driver’s excuse?
Folks who design cars are pretty clever. The air bags did not deploy because they did not need to deploy to protect you. Your headrest protected you.
Be glad, very glad the air bag did not deploy. It is not a soft fluffy pillow. It is a violent rapid expansion of a bag that keeps you from crushing your head or chest on the steering wheel, dash or other solid parts of the car. An air bag will bruise/burn your face, maybe break your nose, maybe break ribs. The trade off is that you are alive. That is a deal I will take any day.
Steve summed it up very well, but I have to correct him on one point
The OP’s head restraint protected him.
And, despite movies and TV shows that persist in showing air bags as soft fluffy pillows that inflate slowly and quietly and then do not deflate rapidly, the reality is just as Steve stated:
If the OP envisions a shotgun shell being fired fairly close to his face, he will get an idea of what the sound of an airbag deployment in a frontal collision is like. Would he REALLY like to experience that situation when it would have provided zero protection in a rear-end collision?