IIHS Releases Small-SUV Roof Crush Test Results

By Chris Haak

03.24.2009

iihs-roof-crushThe insurance industry-funded Insurance Institute for Highway Safety (IIHS) has released its first roof-strength test results for small SUVs, and the results were mixed.  Of the 12 vehicles tested, 4 got the top “good” rating, 5 got the next “acceptable” rating, 2 were rated “marginal,” and 1 was rated “poor.”

The test is conducted by pressing a metal plate against one corner of the roof.  Depending on how many multiples of the vehicle’s weight the roof can sustain without crushing the roof five inches inward, the vehicle receives different ratings.  SUVs rated “good” need to withstand four times the vehicle’s weight.  Those rated “acceptable” need to withstand 3.25 times the vehicle’s weight, and those rated “marginal” need to withstand 2.5 times the vehicle’s weight.  Any vehicle that can’t reach the 2.5 times threshold is rated “poor.”  A NHTSA proposal is for the 2.5 times the vehicle’s weight to be the standard required of all new vehicles, but that is not yet a final rule.  The current standard, dating back to 1973, is for just 1.5 times – and clearly isn’t sufficient.

Models rated “good”:
Honda Element
Jeep Patriot
Subaru Forester
Volkswagen Tiguan

Models rated “acceptable”:
Mitsubishi Outlander
Nissan Rogue
Suzuki Grand Vitara
Toyota RAV4
Chevrolet Equinox/Pontiac Torrent

Models rated “marginal”:
Honda CR-V
Ford Escape/Mercury Mariner/Mazda Tribute

Model rated “poor”:
Hyundai Tucson/Kia Sportage

The importance of strong crush resistance in SUVs should be obvious, but at the risk of belaboring that, I’ll go into it a bit.  First, SUVs – even small ones that are classified as crossovers in most corners of the market – are taller vehicles so are more likely to roll over than a conventional passenger car.  Second, the roof needs to be able to withstand multiples of the vehicle’s weight, because often times, when a vehicle flips over, it’s a dramatic, violent event – not usually a slow roll.  That violence is what makes it necessary for the roof to withstand multiples of the vehicle’s weight.  Think of knocking over a glass that’s sitting on the table – it will make a noise, it might spill your beverage, but it won’t break.  Now drop that glass onto a tile kitchen floor – you get a very different result.

It’s disturbing that Honda’s older design – the Element – has a stronger roof than does the CR-V.  I won’t even beat up on the Kia Sportage, but considering it wasn’t a vehicle that particularly endeared itslef to me in the first place, the fact that it has the weakest roof in its class is just icing on its mediocre cake.  You can see a stark contrast by clicking the opening photo at the top of this article, then clicking through again, between the Tiguan (which showed minimal damage with 15,000 pounds of pressure on its roof) and the Sportage.  There are more photos in the publication from IIHS linked here.

I’d be remiss if I didn’t say a kind word or two about the Jeep Patriot – and presumably the Dodge Caliber and Jeep Compass – and the good performance of those small SUV-like conveyances in these tests.  It’s heartening to know that some otherwise below-par vehicles are setting the standard in safety performance.

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Author: Chris Haak

Chris is Autosavant's Managing Editor. He has a lifelong love of everything automotive, having grown up as the son of a car dealer. A married father of two sons, Chris is also in the process of indoctrinating them into the world of cars and trucks.

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1 Comment

  1. This is good info, thanks.

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