New safety test rates rollovers
The US Insurance Institute for Highway Safety has launched its new roof strength rating system and 12 popular small SUVs were the first to be put to the test.
Of the 12 tested, only four earned the top rating of "good". Volkswagen's Tiguan was rated as having the strongest roof, while the Kia Sportage had the weakest roof structure of the group.
Along with the Tiguan, Subaru's Forester, the Jeep Patriot and Honda Element scored "good" ratings.
The Suzuki Grand Vitara, Chevrolet Equinox, Toyota RAV4, Mitsubishi Outlander and Nissan Rogue's roofs were rated "acceptable".
However, roofs on the Honda CR-V and Ford Escape were noted as "marginal". The Kia's roof received a "poor" rating.
According to Institute research, roofs have gotten stronger over the past few years. This is mostly thanks to manufacturers making structural improvements to earn better front and side crash ratings.
"We anticipate that our roof strength test will drive improved rollover crash protection the same way our frontal offset and side impact consumer test programmes have led to better protection in these kinds of crashes," said Institute president Adrian Lund.
"It's not surprising that Volkswagen and Subaru earn good ratings in our new roof test because these automakers were among the first to ace our front and side tests," Lund points out.
In the IIHS's roof strength test, a metal plate is pushed against one side of the roof at a constant speed. To earn a "good" rating, the roof must withstand a force of four times the vehicles weight (a strength-to-weight ratio) before crushing five inches (127 mm).
An "acceptable" rating is 3.25, marginal 2.5 and anything lower is "poor".