Electric car crash test 2011

[blaaah]

Euro NCAP has published it's report on the all electric Mitsubishi i-MiEV/Peugeot iON/Citroen C-Zero. It achieved a 4 out of 5 star rating. Which has been presented in the independent press as good. But to me I think it is not so good. Cars should get a maximum 5 stars, most do. The batteries were safe in the crash tests, but the structure/potential injuries to me are not acceptable, and I think part of the blame can be give to the high kerb weights for the size of vehicle, they are 1120kgs. At least 100kgs too much mass energy to hit an object with.

"Adult occupant
Inspection of the car after the frontal impact showed that several structures had reached the limit of their load-bearing capacity. The passenger compartment was judged to be unstable as the vehicle might not be able to withstand an impact at a higher speed. As a consequence, the score for the driver's chest was penalised and protection of this body region was rated as marginal. Most of the floor in the driver’s footwell was heavily distorted and this too was penalised, leading to a marginal rating for protection of the driver's feet and ankles. Structures in the dashboard posed a risk of injury to the knees and femurs of both the driver and passenger. In the side barrier impact, the driver's door opened and the car was penalised, although dummy readings showed protection was at least adequate. However, in the more severe side pole test, dummy readings of rib compression indicated poor protection of the chest."
(I can't believe the motoring press are saying this result is excellent and good news)

This is why I think BMW/MINI are onto a winner by designing carbon-fibre lightweight monocoques for their future cars, less weight to offset the heavy batteries and making a safer car as well as more economic and less batteries needed in the first place.

 

[Ibonibo]

Yeah,...
The impact speed in NCAP isn't really high.
This shows an accident in the city with a few km/h more.
Add a few km/h more and the passengers are not in that good condition anymore.
Because the deadly accidents rarly are at 60km/h!

 

[daan]

The way I see it, it "only" gets four stars as it's a really small car. It's powertrain doesn't really have any bearing on it's safety rating. I just had a quick look through the Euro Ncap site and didn't see a car of that size that had 5 stars.

 

[sumbrownkid]

A carbon-fiber monocoque?

Won't that just drive up costs, and I mean really drive it up?

 

[blaaah]

http://www.euroncap.com/results/toyota/IQ/347.aspx
Toyota IQ, maximum 5 stars, excellent car. 886kgs, 234kgs lighter!

A carbon-fiber monocoque?

Won't that just drive up costs, and I mean really drive it up?

It can be cheaper than steel in mass production.

 

[Robin]

Personally I don't see the problem with a car scoring 4 out of 5 because only a couple of years ago that was the norm and many people have survived horrendous accidents in those 4 star rated cars. A 5 star rating has become as useless as the A rated energy efficiency, it really doesn't tell anyone anything anymore because so many products achieve them!

These electric cars are so damn expensive that I guess the savings have to come from somewhere else, the structure! Also the lighter they are the better they perform. Most will never be driven over 30mph anyway so I don't think there is much to worry about.

Robin.

 

[blaaah]

They will also be driven by 17years olds as fast as they can go around country lanes.
If not now then in 5 years time when they are used. Top speed is 81mph, albeit a long time to get to that speed.

 

[Robin]

They will also be driven by 17years olds as fast as they can go around country lanes.
If not now then in 5 years time when they are used.

I doubt most 17 years olds are going to want to choose an electric car as there first vehicle, especially knowing ones priorities at that age! If your 17 and sensible enough to buy an electric car then you probably will be sensible enough to it drive with care.

 

[daan]

http://www.euroncap.com/results/toyota/IQ/347.aspx
Toyota IQ, maximum 5 stars, excellent car. 886kgs, 234kgs lighter!

Those tests would be against a static object.

In real life, when two cars collide the vehicle with the higher mass has an advantage over the lighter one.

So, if an I-miev and an IQ collide, which one are you better off being in? They will also both lose against a "jeep*" or a tree.

I see 4 stars as being perfectly acceptable for a car of that size.


* or other random big vehicle

 

[Tornado]

4 Stars seem fine to me, so I don't understand the outrage in the OP.

 

[blaaah]

I think it is not so good.

4 Stars seem fine to me, so I don't understand the outrage in the OP.

Hardly outrage!

 

[blaaah]

Those tests would be against a static object.

So, if an I-miev and an IQ collide, which one are you better off being in? They will also both lose against a "jeep*" or a tree.

I see 4 stars as being perfectly acceptable for a car of that size.


* or other random big vehicle

The IQ is a lot safer, it is lighter and has maximum 5 star rating, this electric car has only 4 stars, it is more dangerous to travel in.
I think what NCAP have said by weight v weight is BS scientifically, they are just using an old fashioned rule, which has worked over time. But not when the weight in this instance is coming from dead weight, not structural weight.
If you have an IQ weighing 900kgs hitting a truck weighing 2000kgs, and another IQ weighing 1100kgs hitting a similar truck. The lighter IQ will be much better off, as it will have the same structural strength but less mass energy to crumple through it or change direction and bounce off.

An IQ will be better off hitting an i-MiEV.

It could depend on the type of crash though to be fair. But I believe in the bouncing off safety rather than plough on through the object safety...

There are also plenty of static objects to hit on a drive, hedges, walls, trees. Better to hit them in an IQ than a i-MiEV.

 

[Tornado]

Which would be great if that was all you said:

but the structure/potential injuries to me are not acceptable

(I can't believe the motoring press are saying this result is excellent and good news)

And I'll also add that the bit about how forward-thinking BMW is for putting a carbon fiber monocoque into the Mini concept car is pretty moot because there is no way that that car will actually be built like that, assuming it is built in the first place.

 

[homeforsummer]

These electric cars are so damn expensive that I guess the savings have to come from somewhere else, the structure!

Irrelevant, since the only EV on a dedicated platform at the moment is the Nissan Leaf. As Daan said, the drivetrain has absolutely no bearing on the safety. The i-MiEV is based on the petrol powered 'i' which has been on sale in the UK for three or four years now.

Toronado - The BMW is being designed with a carbon monocoque, but then it'll probably be quite expensive to make up for that. Not really a competitor for the Mitsubishi, at any rate.

 

[Tornado]

What BMW?

 

[homeforsummer]

What BMW?

Ah, sorry, I saw "BMW" in your post and assumed you were talking about the MegaCity concept they're currently developing (that'll teach me not to skim read). It's going to be a small, electric city car with a carbon monocoque. I didn't realise you were talking about the new MINI concept. In which case you're right, I doubt the MINI will have a carbon tub.

 

[blaaah]

Drivetrain has an strong effect on safety, the batteries weigh a lot more, this makes the car more unsafe in an impact, as well as the obvious fact of weight making the the car harder to slow down in the first place.

 

[Tornado]

Weight barely has an effect on braking ability.

 

[Leonidae@MFT]

But on stopping distance it does.

 

[Tornado]

No it doesn't. Or, rather, so long as Mitsubishi took the increased weight under consideration when tuning the suspension, the increased weight makes no difference.

 

[homeforsummer]

Drivetrain has an strong effect on safety, the batteries weigh a lot more, this makes the car more unsafe in an impact, as well as the obvious fact of weight making the the car harder to slow down in the first place.

Stopping distance can be affected, but the weight of the batteries will have next to no effect in an impact.

Electric cars are no less inherently safe than regular cars.

 

[Robin]

Irrelevant, since the only EV on a dedicated platform at the moment is the Nissan Leaf. As Daan said, the drivetrain has absolutely no bearing on the safety. The i-MiEV is based on the petrol powered 'i' which has been on sale in the UK for three or four years now.

Wait so your telling me Mitsubishi didn't change one inch of that car for the electric version, didn't touch one bit of the chassis or internal structure...

I'm sorry but its slightly gullible to think that just because its based on the same platform that changes have not been done to the car on a major level, so where does the battery go? how is that bolted in and what was there in its place on the petrol version...

Robin.

 

[Tornado]

Wait so your telling me Mitsubishi didn't change one inch of that car for the electric version, didn't touch one bit of the chassis or internal structure...

Actually, from what I've been able to read up about with the car's design, they really didn't.

so where does the battery go?

Underneath the floor.

how is that bolted in and what was there in its place on the petrol version..

The... um... petrol tank?

 

[Robin]

Um, you missed the point and those were rhetorical questions!, I was trying to show that there have been major changes to the car... a petrol tank and a battery are not going to crumple the same in an accident so to say that its an identical platform is nonsense.

 

[blaaah]

I will bet here that the Nissan Leaf will get a worse crash report than cars of similar size, because it will weigh more...

 

[Omnis]

I will bet here that the Nissan Leaf will get a worse crash report than cars of similar size, because it will weigh more...

The only correlation between mass and crash results is the increased energy against the static object. By your logic, I hope the car you're driving is several hundred pounds lighter than mine if you decide to crash into me.

 

[blaaah]

If I played an imaginary gamer of conkers with 2 baked bean cans, both fully intact and sealed but 1 empty 1 full, the weight difference is large. But swing them into each other, the damage would be less to both cans, than if they both were of equal weight.
That's how I see it, it might be wrong. But even if that is wrong, I would rather be in the empty bean can rather than with the beans when they both get swung into a concrete wall.
That might be taking a metaphor too far.

 

[Tornado]

Um, you missed the point and those were rhetorical questions!, I was trying to show that there have been major changes to the car... a petrol tank and a battery are not going to crumple the same in an accident so to say that its an identical platform is nonsense.

No. I completely understood the point. Rhetorical or not, the point that those questions were trying to prove was wrong, plain and simple. The platform is identical. The structure of the crumple zones are identical. The location of the powertrain is identical. Mitsubishi did not change anything. If you read the press release that they put out with the car, you'll note that it goes out of its way to mention how easy the transformation to a plug-in hybrid was, and they even noted specifics regarding the issue.

And since the batteries and motor are mounted dead center underneath and in the rear of the car, respectively, them having different physical characteristics to the petrol tank and engine would cause absolutely no change regarding frontal and side impact tests except for the difference in weight. A difference in weight which, I think it must be said, isn't really that much different from your typical base model sedan when compared to the top trim level (normal Mitsubishi i weighs around 900kg).

 

[Omnis]

If I played an imaginary gamer of conkers with 2 baked bean cans, both fully intact and sealed but 1 empty 1 full, the weight difference is large. But swing them into each other, the damage would be less to both cans, than if they both were of equal weight.
That's how I see it, it might be wrong. But even if that is wrong, I would rather be in the empty bean can rather than with the beans when they both get swung into a concrete wall.
That might be taking a metaphor too far.

Those are some El Duderino physics at work. You're still going to have the same magnitude of deceleration no matter what bean can you're in if you knock into an immovable object.

If you swing a full bean can into an empty bean can, the full one is going to decelerate at a slower rate due to inertia. It's always safest to be accelerating slowest.

 

[niky]

The reason the iMIEV gets "only" four stars is because the base car does. A four-star rating on the Euro-NCAP for that size of car four years ago is quite good.

By your logic regarding weight and crash integrity, the gasoline version should get five stars, but it doesn't.

The Toyota iQ weighs less, but it seats only three. For all that weight, the iQ has a smaller passenger cabin, so the comparison is quite moot.

You're right that the mainstream press have got it all wrong... because the crash-rating says nothing about the safety of electrics. It merely shows that an electric is only as safe as its platform donor.