IIHS Tests Small SUVs for Rollover Safety

Following the safety concerns that the Ford Explorer and Firestone debacle have arisen in recent years over rollover safety for SUVs, governmental agencies and automakers alike have been working to improve vehicle safety without hurting vehicle weight and fuel economy. For the Insurance Institute for Highway Safety (IIHS), it has enacted a tougher set of standards for vehicle roof strength that far surpass that required by the National Highway Traffic Safety Administration (NHTSA). The IIHS says that more than 10,000 people each year are killed in rollover crashes and increasing the roof safety will help save countless numbers of lives. Recently, the IIHS tested a dozen small crossover SUVs using its new testing system and came up with surprising results. Although all of the vehicles tested conform to the NHTSA’s roof strength standards, only four of the small crossovers received the top rating of “Good” from the IIHS.

The goal of the new test is to see how well the roof holds up in rollover crashes which is important to avoid injuries and prevent fatalities. As cars, trucks and SUVs getting bigger and stronger, their weight increases as well adding to the strain that the roof must endure to protect vehicle occupants. Current governmental roof standards date back to 1973 requiring a roof strength-to-weight ratio of only 1.5 – meaning that the roof must withstand a weight one and a half times the vehicle’s total weight – and does not apply to bigger vehicles such as pickup trucks and SUVs. Although the NHTSA proposed strengthening its standards to 2.5, the IIHS is rating anything under this increased proposed mark as poor. To attain the Institute’s “Good” rating, a roof must withstand a force four times the vehicles weight, and the roof ratings will become required criteria to attain the coveted Top Safety Pick starting in 2010.

The IIHS began its new testing procedure on 12 2009 model compact crossovers and SUVs. To earn a “Good” rating, the vehicle’s roof must withstand a force of four times the weight of the vehicle, applied directly to the driver’s side of the vehicle to the A- and B-pillars, before reaching five inches of crush. The top performers in the inaugural tests were the Honda Element, Jeep Patriot, Subaru Forester and Volkswagen Tiguan. The Tiguan stood out as the top vehicle with almost little visual damage, although the roof crushed in about two inches, other than slight buckling of the roof after almost 15,000 pounds of force were applied to its roof. Pictures of the other vehicles under the normal procedure are not yet available.

For an “Acceptable” rating, the roof must withstand a force of at least 3.25 times the vehicle’s weight. Vehicles that attained this rating include the Chevrolet Equinox, Mitsubishi Outlander, Nissan Rogue, Pontiac Torrent and Toyota RAV4. The next rating for the IIHS is “Marginal” requiring the roof to withstand at least 2.5 times the weight of the vehicle (still stronger than current NHTSA requirements). The Ford Escape, Honda CR-V, Mazda Tribute and Mercury Mariner all attained a “Marginal” rating.

The lowest rating for roof strength is “Poor,” which indicates a roof strength that cannot withstand at least 2.5 times the vehicle’s weight. The Kia Sportage and Hyundai Tucson (which are sister cars) both received “Poor” ratings. Unlike the Tiguan, the Sportage’s roof collapsed so far under pressure that the roof and B-pillar would have definitely made contact with the driver’s head leaving severe injuries. The windshield and side windows were also shattered, while none of the Tiguan’s windows were broken.