Officials Release Comprehensive Rollover Rankings. Federal auto safety officials plan to release the first comprehensive rollover rankings Monday, including how likely a vehicle is to roll over in a single-vehicle crash.
The new list from the National Highway Traffic Safety Administration augments, but does not replace, the agency’s five-star rating safety system for vehicles. It is intended to give a more accurate assessment of vehicle stability than provided by the star system.
That system awards five stars to vehicles least likely to roll, dropping to one star for those very likely to roll, based on NHTSA tests and a formula that takes vehicle dimensions and center of gravity into account.
The new system will allow shoppers to distinguish, for instance, between a sport-utility vehicle that barely earns four stars and one that’s stable enough to easily get four stars â€” a distinction not possible using star rankings. NHTSA says that vehicles with four and five stars in the current system will score well in the new rankings.
SUV Are Most Likely To Cause A Stir
While the rankings will include all types of vehicles, ratings of SUVs are most likely to cause a stir.
There were 456 more deaths in SUVs in 2003 than in 2002, and 55% of those were in rollover wrecks. NHTSA chief Jeffrey Runge has said SUVs can be very safe as long as “you don’t roll over.” No SUV receives the top, five-star, score in NHTSA’s current ranking system.
Barry McCahill, president of SUV Owners of America, says the new rankings could mislead consumers, who “should also evaluate safety based on how vehicles perform in real crashes not just one test track result and one tape measurement of physical dimensions.”
The agency has been ranking vehicles’ tipsiness since 2001, using the formula. Starting with ’04 models, some vehicles, mainly SUVs, also have undergone moving tests to gauge stability.
The SUVs that have scored highest, with four stars, are General Motors’ traditional truck-based, midsize SUVs sold as the Chevrolet TrailBlazer, GMC Envoy, Oldsmobile Bravada and Isuzu Ascender; car-based, crossover SUVs Volvo XC90, Honda Pilot, Buick Rainier, Subaru Forester, and the truck-based Dodge Durango.
All other vehicles tested by NHTSA earned three stars, except the Ford Explorer SportTrac, which got two stars.
About 12 newly tested vehicles, not currently listed among NHTSA test rankings, will be among the rankings NHTSA will announce next week.
NHTSA will also release results of preliminary testing of stability-control systems, which detect when a vehicle is not heading in the direction a driver intends and use brakes and engine power to bring the vehicle back in line. NHTSA is expected to continue to offer qualified support for the systems. The agency has found it difficult to gauge their precise effectiveness because systems and vehicle suspensions differ.
Ford Motor announced last week that all of its SUVs will have stability control as standard equipment. All 2004 Toyota and Lexus SUV models have standard stability control.
In a NHTSA test last October, a Toyota 4Runner SUV with stability control kept all four wheels on the ground in swerves up to 50 miles per hour, while the same SUV without stability control would have rolled over in the test maneuver at 35 mph, NHTSA said.