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View Poll Results: Does more heavy, mean more safe?
Yes 25 22.12%
No 59 52.21%
Maybe 29 25.66%
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Old 5th May 2006, 19:15   #46
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if the car is heavy , it takes time to reach a higher speed so if thers a truck speeding your way and the only way to survive is revv hard , a light car will just rush and survive but a heavy car will take time and get banged .
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Old 5th May 2006, 19:22   #47
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Quote:
Originally Posted by Zappo
Ok... maybe I should sum-up my previous post... in continuity to the previous one lets say that if I took two vehicles which are same in all aspects the heavier one may have an edge. Lets say we have two Altos... One is the regular one but the other one made heavy on purpose by adding a lot of extra weight (metal?!). Now if the two ram into each other the lighter Alto will always suffer more.

Above theory directly comes out of physics. At a given speed the heavier vehicle will always have more momentum at the time of the crash. Now if everything else is the same the lighter vehicle will have to bear the brunt because of the higher momentum of the heavier vehicle.
I agree with you completely.
But the thing is,in most of the discussions in this forum, we are not comparing a lighter Alto and a Heavier Alto. We compare Alto with Indica, we compare Esteem and Indigo (just some examples), and blindly some people announce that the heavier car is more safer, since it weighs more. It is then, that the original question of this thread, becomes relevent.

Last edited by DCEite : 5th May 2006 at 19:24.
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Old 5th May 2006, 19:36   #48
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Quote:
Originally Posted by DRC
That would be wrong, as the design of both the cars are different,

OK, for the sake of arguement, let's take say Alto OR Indica, with engine and without an engine ( Now dont laugh, its only a theory) to make it ligher, Drive/hurl the car to say 60KMPH, and crash against some thing, then the car with out an engine will be more safer, as the wieght is less..

Or in other words, if you can make a car lighter and provide same strcutural rigidity, say by using composite materials, then the lighter car would be more safe, as it build less kinetic energy, which is fatal.
why do you say that?
wont the engine absorb the force of the crash causing less force to be passed on to the passengers?

basically the car should be designed such that the components break off after absorbing the force of the crash.

its not tht a car tht isnt deformed too much is safer. cos tht means tht the car hasnt abosorbed the force of the impact and the passengers have which means more injury to them.

WEIGHT HAS NOTHING TO DO WITH SAFETY ITS ALL ABOUT DESIGN.
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Old 5th May 2006, 19:48   #49
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Quote:
Originally Posted by koooliooo
if the car is heavy , it takes time to reach a higher speed so if thers a truck speeding your way and the only way to survive is revv hard , a light car will just rush and survive but a heavy car will take time and get banged .
Koooliooo, in such case, the problem is not with the car, but with the driver. Use the same car (light or heavy, whichever the case may be) and fire that driver
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Old 5th May 2006, 19:50   #50
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A light car can be safe...but all in all a heavier car will be better able to withstand a crash and save its occupants provided its been engineered to provide safety.

When we look at crashed cars and see the damage...the car with more damage doesnt necessarily mean less safe...
Cars these days are meant to get deformed and absorb all the impact so that the occupants are safe.
The rigidity of the passenger cabin is all that matters...rest of the car is essentially meant to be destroyed in case of an accident.

The passenger cabin in a heavier car will be more rigid. Example of an alto and an indica.
The difference lies in the design of the car.
If both cars are subjected to an identical crash...the indica will be better off.
Why is a certain car heavy? Mostly its because of the amount of metal used. Just take a look at the thickness of the door of an alto/santro/wagon r and compare it to the indica.
The metal thickness also accounts for the cabin rigidity.
So when people say heavier is better...its true to a certain extent...in modern cars...im not talking about ambassadors or cars from that era.

Again i'd say heavier doesnt necessarily mean safer...check my previous posts. Its the design that matters.

Drifter

Last edited by drifter : 5th May 2006 at 19:51.
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Old 5th May 2006, 20:09   #51
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Quote:
Originally Posted by koooliooo
if the car is heavy , it takes time to reach a higher speed so if thers a truck speeding your way and the only way to survive is revv hard , a light car will just rush and survive but a heavy car will take time and get banged .
exactly... and also the other way round, if the only way to survive is to stop before you enter a danger zone, lighter cars will do a better job assuming both cars have brakes with simlar capability
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Old 5th May 2006, 20:56   #52
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Quote:
Originally Posted by drifter
The metal thickness also accounts for the cabin rigidity.
r
Yes, but for sheets the shape is more important that the thickness for its rigidity... a sheet in convex shape (swollen) is much more rigid as compared to flat one. Somebody had given another nice example of honey-comb shape. One more example which everyone must have seen is corrugated paper sheet used for packing big consumer items. Imagine how weak those boxes would be if all paper sheets were used flat without wrinkles! Also, strenght of the pillars, side prtection bars and other structures behind the outer skin constitute most of the cabin's rigidity. Above all, significant portion of car cabins is just glasses (windows included, which I don't know if they are as safe as front wind shield, but are definitely weaker than steel!)

IMHO, I can sum up the relation between weight and safty like this-

-safty of the passenger is what we are discussing, not the safty of cars!
-Only passenger cabin needs to be strong, stronger (not necesarily heavier) the better
-boot/bonnet should be strong enough to bear all the impact but weak enough not to directly pass it to the cabin, additionally the material used should absorb the impact, it must not store it like springs.
-for rest of the parts, lighter the better. any additional weight has only adverse impact

Regarding other safty features:
- good set of brakes/tyres/steering and seatbelts are primay features that make a big difference to the safty (and not to the weight!).
- ABS, airbags, EBD are secondary (and many times debatable )
- It is sheer foolishness to buy a car based on its european safty rating, but it lacks those airbags and other advanced safty features (which might be big contributors for that rating!)

Maruti website has some very good piece of information on safty. (No, I am not defending MUL, I honestly found that info. to be quite logical!)
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Old 5th May 2006, 21:16   #53
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Take a maruti 800 and put in say..... a Dicor engine in the back to make it a rear engine RWD and you'll end up with a 1.6 ton car............but its less safe than the original.

Those of you who have studied physics/SOM know that its not weight but ultimately the stiffness and the strength of the front crash structure that determinesthe impact absorbsion capability. It only a general trend that heavier structures are more stiff and strong.

You also need to use high strength steel and a progressive crumple zones
to get the best performance
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Old 5th May 2006, 22:55   #54
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Santosh Seems to have got the point,
Most important aspect is the design, No second word about it at all.

Design should be like, the possible area of collision be weak, and collapsible, able to absorb energy (where did the energy come from?), divert forces to other directions in a way least possible to be passed on to the occupants...and cabin should be rigid, and strong to minimize structural/geometric deformation.

Let us take an hypothetical, example, all this is aken care in car, and exactly identical to an another car in all aspects, but only lighter. Hope you are getting the point.

Now, at an identical event of collision, the car has less amount of energy (which I mentioned earlier, KINETIC ENERGY), to be absorbed. That is the reason, I would say, lighter the car safer. AND by no way means compromise on the design for safety.

Yes, making the cabin rigid, involves more metal and hence heavier,So it appears, heavier the car, safer...
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Old 6th May 2006, 00:46   #55
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Quote:
Originally Posted by tsk1979
the Indica is indeed safer than WagonR or santro
1. Its less likely to topple than both of these
Of the 2 or 3 cars that I remember seeing toppled after road accidents, all have been Indicas. Have never seen (or heard) of a Wagon R toppling and only Santro I've seen toppled was after 26/7 in Mumbai when one Santro was carried by massively gushing flood waters and thrown aside.

Just my personal experience, for whatever it's worth.
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Old 6th May 2006, 12:15   #56
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my vote went for MAYBE since a lot of times heavier cars are more safe. take the example of opel astra, much heavier than an esteem but much much safer.

there is no general rule for them so MAYBE was the right choice.
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Old 6th May 2006, 12:19   #57
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Mahindra vehicles are heavy ,tata vehicles are heavy,ambys are heavy .. what makes them heavy ? Even though they are heavy ,they still rust ,breakdown . where as the marutis ,hyudais ,toyotas are lighter ,dont rust ,perform better .

The key to all this lies in the fact that the quality of metal used ,alloys used is totally different . I always had a notion that all the mahindras and tata vehicles were made from pig iron quality sheets . iron in its basic form is heavy ,prone to corrosion and can break easily ,where as steel is much better .

secondly ,if you guys have a chance please look at the alternator brakets ,radiator brakets in the mahindras and tatas . they are plain with no shape or design in them . there are no fatigue zones or crumple zones .. this holds true for alternator brakets as well . where as in the new generation indian cars ,the brakets are either designed with the engine or you coukld just screw the radiator on the body of the vehicle . and the brakets are always pressed sheet metal instead of rods and they are designed to be light weight yet the brakets are more rigid .

design is the key to reducing weight .
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Old 6th May 2006, 12:45   #58
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Quote:
Originally Posted by ivor
Of the 2 or 3 cars that I remember seeing toppled after road accidents, all have been Indicas. Have never seen (or heard) of a Wagon R toppling and only Santro I've seen toppled was after 26/7 in Mumbai when one Santro was carried by massively gushing flood waters and thrown aside.

Just my personal experience, for whatever it's worth.


Exactly my thoughts and experience.

And i am not one of those who will jump to conclusions just because we are comparing "heavy" Indica with the so called "Unsafe" tall boy design.

Unless and until we have crash ratings for the Indian versions of Indica and WagonR, i dont think it is wise saying which one is more safer.
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Old 6th May 2006, 12:55   #59
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oh man...havent you seen accidents involving marutis? Not saying that wagon r or santro or whatever is unsafe...but looking at the accidents on all the said cars. Im happy with the indica.

I have been in a collision with a maruti 800 at a crossroad. The car hit 90 degrees from the driver side...i only had a broken window glass and a dent whereas the 800 was spent. The side impact beams in the indica are huge, trust me they saved me. These exact same beams are part of the reason why the car is heavy and safer.

Drifter

Last edited by drifter : 6th May 2006 at 12:57.
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Old 6th May 2006, 13:22   #60
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Quote:
Originally Posted by drifter
oh man...havent you seen accidents involving marutis? Not saying that wagon r or santro or whatever is unsafe...but looking at the accidents on all the said cars. Im happy with the indica.

I have been in a collision with a maruti 800 at a crossroad. The car hit 90 degrees from the driver side...i only had a broken window glass and a dent whereas the 800 was spent. The side impact beams in the indica are huge, trust me they saved me. These exact same beams are part of the reason why the car is heavy and safer.

Drifter

You are not getting my point. I am not concluding anything about safety of Indica vis a vis WagonR/Santro.
What i am saying is that its childish to just jump to conclusions on the basis of shape(tall boy etc.) and weight.

And if at all the number of accidents was any indicator of safety, then i would start to believe its Indica which is at the receiving end, after seeing a couple of toppled and burnt ones.


Let there be EuroNcap type crash tests ratings, we will know then which one is safer.

Last edited by DCEite : 6th May 2006 at 13:25.
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