Washington A 2001 Pontiac Aztek got four of five stars in the government's rating of rollover risk, the best score given yet to a sport utility vehicle.
The National Highway Traffic Safety Administration released the last of its ratings for the 2001 model year and the first for 2002 on Tuesday.
The ratings are based on an arithmetic formula using the vehicle's center of gravity and width. The more stars, the lower the rollover risk. SUVs and pickup trucks are more top-heavy and thus more likely to get low marks than a car or van.
Real world accident statistics also show pickups and SUVs are more likely to roll over. More than 60 percent of fatalities in SUVs and more than 40 percent of deaths in pickups happen in rollovers.
By comparison, 22 percent of car deaths involve rollovers.
Until the Aztek 4X4 earned four stars, no SUV had gotten more than three. The Aztek 4X2 got a three-star rating earlier this year.
The 2002 models will be the last rated by the mathematical formula.
Under a new law, NHTSA must begin conducting rollover driving tests for the 2003 model year.