52 States in 8 Months

Buy a Volkswagen!

Posted in Europe by Ulf on May 4, 2009

A friend of mine works at the “Insurance Institute for Highway Safety” (IIHS) in Arlington, Virginia. The institute is financed by insurance companies who try to make customers aware of the safety qualities of their cars. In a recent research paper and an easily readable article they’ve published the results of a roof strength test.
kia_vw
The idea is to simulate the effects of a car rollover. It is hard to define representative conditions for a dynamic crash test with dummies (because a roll-over does not happen by itself, it might involve cornering, driving over large obstacles or a side impact to mention just a few), therefore the IIHS measures the roof strength in a static way: They define the “strength-to-weight ratio” (SWR) as the ratio between the car’s gravity force and the force which is required to crush the roof by a certain distance, either 2 inches (5cm) or 5 inches (13cm). This force is exerted by pressing a plate against the driver’s side of the roof. In the 5in-test, a ratio of 4 and above is considered to be good while a ratio of 2.5 or less is considered to be poor.

I could not find the results of the 5in-test, but they’ve published the results of the 2in-test: A VW Tiguan already reaches a SWR of 4.3 in the 2in test. This is a result which would have even rendered a good grade in the 5in test! Only half the force was required to crush the roof of a KIA Sportage (with roughly the same weight) to 2 inches. The full 15000 pounds (about 66kN) that deformed the Volkswagen roof only by 2 inches were enough to completely bring down the KIA roof. To state this explicitly: The following two cars both have a weight of about 1.6 tons, are about 4.4m long and about 1.8m tall (the KIA is even a bit larger/heavier than the VW), and the same force has been applied to their roofs:

vw_kia_roof_strength_test

That means that you can stack at least five VW Tiguans on top of each other before it gets dangerous for the passenger in the lowest VW, but you should not build a tower of more than three KIAs. Their roof will simply squeeze down. I wonder how the Humvee would have performed in this test. The German Wikipedia claims that up to three HMMWVs can be stacked onto each other to fully utilize the load space on cargo vessels, SWRHMMWV≥2.

PS: When I opened the picture of the KIA a few minutes ago my Korean room-mate proudly said “That’s a KIA, a Korean car.” Well… now he claims that not all Korean car manufacturers are like that ;-).

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One Response

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  1. Tommy said, on May 5, 2009 at 2:43 am

    okay, convinced. i’m gonna roll the polo intentionally.
    but i’ll blame you if it gets damaged somehow. … ;)


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