So glad my MX-5 did NOT have the 'Active Bonnet' feature.

Technical Area Body, Interior & Styling
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Well, the headline says it all really.

The other day, whilst enjoying a sunny topless drive in my MX-5, I swept around a bend, passed a farm, and happened across a pheasant standing in the middle of the road.  I was doing about 50 mph, and with no chance to stop or swerve, hit the thing head-on.

Now these creatures are pretty stupid it must be said, as it just stayed there, looking at me, awaiting the inevitable, without even attempting to fly off.  It was quite a thump I can tell you.  I assumed that the front suspension would have taken the brunt of the collision, and upon inspecting the damage, so it proved.  However, part of the unfortunate creature, its head perhaps, must have hit my off-side front fog light, because this had been dislodged, and was dangling, supported only by its wiring loom, in the void between the bumper and the wheel-arch inner liner.  A quick ten-minute job to refit it, and I was good to go again (apart from having to wash off some blood and feathers that is !).

Imagine if you will, if my 5 had been fitted with this ‘Active Bonnet’ feature.  It would almost certainly have deployed, causing perhaps two grand’s-worth of damage to an otherwise unmarked car.  OK, so I may have been able to claim from my insurance provider, but as my 5 is ten years old, who’s to say that they might have deemed the repair as uneconomic, and written-off my car ?

As I understand it, this feature is present on MX-5s from the mk. 3.75 version - 2013 onwards or thereabouts, and in a few short years, this scenario could quite likely be repeated for owners of the later model 5s.

Personally, I detest the whole idea of this system, and have read a number of posts on this forum about this feature being deployed for only minor mishaps, like mine.  To my mind, this is one road safety feature too far ! 

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Fully agree Chris - & pleased that your car suffered no permanent damage!  My Dad once hit a pheasant with his 1995 Ford Escort - that was the model where the front of the bonnet extended right down to the top of the bumper - the result was a football sized dent above the bottom edge of the bonnet & a new bonnet had to be fitted.

The active bonnet was fitted to the Mk3.75 / NC3 which was sold from 2013 onwards - I’m pleased that my Mk3.5 doesn’t have this “enhancement”!

 

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I really do not understand this attitude at all. Would the following be an acceptable post?

“I’m really glad my car hasn’t got an active bonnet - I was driving at 20mph and a child ran out in front of my car - their head hit the engine and now they have permanent brain damage - but I’m happy because my car is not a write off!”

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A well-meaning but unrealistic comment.

I so glad I don’t have it on my car, even at 20mph. However we won’t need in a few years time as you won’t be able to drive the car when is see anything on the road, in a tree, behind you or even in the garage…Cool it will stop… 

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Yes, active bonnet came in with the MK3.75 so a 2012 MK3.5 will be blissfully free of it.

I do get annoyed with the view that owners who complain about this system because a conker set it off and it has cost them a fortune in unnecessary damage repairs are somehow irresponsible!

If you want to avoid any possibility of harming someone in a car don’t drive - it is that simple. To intimate that active bonnet is the answer to all road traffic accidents is silly. I wonder how many of these people actually have active bonnet on their cars or will only drive/be a passenger in a car if it has active bonnet.   

A car is capable of devasting damage to property and people/animals, even when driven perfectly responsibly and within the law. To completely and undeniably avoid that possibility don’t use any motor vehicle.  

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6 months ago the driver of an van decided to turn right, in broad daylight, across the path of the bicycle I was riding. Time slows down and I could describe the bumper and fog light openings in intimate detail. Anyway a trip across the bonnet, 3 rotations before I end up in the gutter. Two police cars, one ambulance, one driver in shock wandering round telling everyone he could find that “I just didn’t see him!” The one person however he didn’t say it to was me as the copious amounts of blood issuing from the 4" wound right by my Femoral artery was quite off-putting to him. It turns out that thin vehicle bodywork is actually quite hazardous to flesh and also 13 stone of human makes quite a mess of bodywork when you use it as a battering ram at 25 miles an hour, active bonnet or not. 

Anyway, after some pretty urgent surgery it turns out that, luckily, my bodywork wasn’t a right off. As self employed though, the resultant time in the bodyshop did cost me thousands to get back to a roadworthy condition. The driver of the van, and me me for that mater, probably still thinks about the day someone they knocked down nearly blead to death in front of their eyes.

If you want to drive a low sports car, accept that certain concessions need to be made to allow you that privilege and that not all “safety” is because of “the other idiots that should take care.” If you don’t want to have to worry about active bonnets, buy a Sprinter van. 

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The problem I have with the active bonnet is this:

I have been driving for 43 years and have always had a policy of don’t swerve to avoid small animals as it is safer for me and my fellow human road users if I flatten a rabbit than to suddenly brake or steer unpredictably while in traffic and potentially be the cause of a multiple-vehicle collision.

Now faced with a wrecked car in the event that a small furry creature suddenly crosses my path I find myself doing whatever it takes to avoid it meeting my bumper. This has only happened once so far since I got the MX5, on an otherwise empty road in rural Rutland when a pheasant ran across in front. I am very glad there was no traffic following close behind as I really gave the brakes a good test.

 

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Your RTA happened (which I’m sorry to read) and I’m sure as you say the drive still thinks about it, but it was because the driver as you clearly stated “he did not see you”… nothing to do the make, model, or active bonnet fitted or not to the car or van.

If potentially causing of a multiple-vehicle collision because a driver steers unpredictably while in traffic as he/she is worried about the 'active bonnet" system deploying when a rabbit runs across the road. Then faced with a write off, because the insurance company deems the car will cost to much to replace the active bonnet system is just ludicrous.

Let me make it very clear I’m NOT against the idea of active bonnet systems. I’m just glad I don’t have it on my car.

John

 

 

 

 

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I’m sorry to disagree, but I find it ludicrous that this is such a difficult concept to get around. Current vehicle design law is that  production cars are pedestrian “crashworthy” at low speeds. It is part of the Euro NCAP testing program.

If you want to drive a low bonnet line car, it is what is required. That the van driver did not see me does not make it a less worthy feature but more so. Would your view be different if your wife, daughter, son, family member or best friend were prevented from having their brain splattered up car windscreen, because severe head trauma is what these things are all about preventing, by this feature? Or even when the first thing you see of the pedestrian is as they ricochet off your bonnet because you “didn’t see them” would you be thinking, well, at least I won’t have a big bill and the blood will simply wipe off?

These are not design faults in the same way as if you happen to rear end a car, even at low speed in a traffic queue your air bags are going to deploy and the resultant cost of replacing the dashboard, steering wheel, windscreen, let alone the front end damage is going to write your car off even if you literally are driving it off the forecourt at the time.

It is being debated in the news at the moment that certain safety features of the Boeing 737 Max were additional cost options and if we’re fitted as standard then a great many people would not have died. I would hate to be in a position of having to either having to tell a greaving family that their loved one was dead because I didn’t want to pay for the safety feature that would have saved their lives, or that I had disabled it because I didn’t want to risk a repair bill. 

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The idea of active bonnet is a good one but from owners comments the practical application does not match the concept.

Not heard of a single incident where active bonnet on an MX5 has done the job it was designed for ie. saved a pedestrian from serious head injury. There have however been numerous examples of active bonnet activating with minimal impact where the danger of a real accident is increased by the unexpected activation of active bonnet. Further it seems that owners are quite understandably compromising their sensible driving by swerving to avoid pheasants, rabbits, etc to avoid active bonnet activation. Again this risks accident as a result of active bonnet. Quite simply active bonnet on the MX5 is counterproductive. A clear example where the pruduct theory and practice are a long way apart  

Not sure what the solution is but active bonnet does not appear to be working as intended and in my opinion needs some re-engineering.             

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Another problem is some owners are re-engineering the system by disabling and removing it, where does that leave them in the result of an accident. Sealed

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not insured  

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I don’t understand why the active bonnet needs to be destructive. Surely it is not beyond the skills of the design engineers to be able to create a bonnet that can raise quickly when tripped, but which may then be clipped back down without having been terminally deformed in the process when a minor triggering event has taken place.

Obviously where it has been triggered by a serious event that involves protecting an unfortunate pedestrian who has been thrown across the car, in that case there would be an expectation of of significant damage.

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Firstly because I very much doubt anyone is going to come on this forum and say, "I knocked a child down today. I’m really glad I had an active bonnet.

No one has said hitting a rabbit sets this off, this post is about hitting a pheasant at 50 and I would very much suspect that it would be disabled at this speed any way. Those that have had these deployed have, unfortunately been unlucky as the engineers will have to work with a single impact scenario within a set speed range and if that criterion is met, deployment will happen. 

As for those asking why the deployment is so brutal, because the window for deployment is so small. Watch the video to the end and think if a couple of springs and clips and a half second deployment time would work?

https://youtu.be/VmN6ie3xjE8 

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Good point Martin.  Surely it’s possible in the 21st century, to develop a material that could be fitted under the bonnet to absorb the energy of the impact of a body landing on it without wrecking the car !  And surely this would be less expensive for the car manufacturer to fit in the first place, as well as not requiring expensive repairs for the owner should the unfortunate happen !

Having said that, with the aluminium bonnet as fitted to the MX-5, not being as structurally strong as the equivalent steel version, I expect if a body did land on it, it would probably need replacing anyway. 

But that is not really the point of this argument - which is that the system of deploying the ‘Active Bonnet’ (on the MX-5 anyway) seems to be flawed and unreliable, in that it seems to go off when it is not supposed to, causing unnecessary damage to the vehicle to which it is fitted.   

 

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It seems inevitable that when a body has landed on it the front and bonnet of the car will be damaged, regardless of whether it’s an active bonnet or not.

If you means a false activation, as I understand it the car isn’t wrecked - just the bonnet, hinges and ‘bangers’ need to be replaced.  It just happens to be an expensive job.

It is possible to design a bonnet, or structures under it, that will absorb the energy without “deployment” if you have space.  That is the issue with the MX-5 and other cars with low bonnets that have hard points immediately underneath.

I won’t be overjoyed if my bonnet deploys for a rabbit or pheasant, but I’d just have to get on with it, in the same way as with any other accidental damage that is beyond my control.

 

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They have - it’s called air - you just need enough space to store it.

 

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Can’t help thinking that a steel bonnet without explosive charges might be just as effective in preventing injury, less of a liability and a whole lot cheaper.