A silver lining for Toyota, which has been under the dark cloud of unintended acceleration and braking failure recently.
The Insurance Institute for Highway Safety has selected to two Toyota models -- the Scion xB and Toyota Corolla -- for its Top Safety Pick awards.
The naming of the xB and Corolla brings to seven the number of small cars consumers have to choose from that earn the Institute's highest safety designation. It's the second straight year the two models have earned the Top Safety Pick designation.
To qualify, a vehicle must earn the highest rating of good in the Institute's front, side, rollover, and rear impact tests and be equipped with electronic stability control. Electronic stability control significantly reduces rollovers, especially fatal single-vehicle ones.
The xB and Corolla are the first Toyota models to earn Top Safety Pick since the Institute tightened the criteria to win by adding the new rollover test for 2010.
To earn a good rollover rating, a roof has to support the equivalent of 4 times the vehicle's weight compared with the current federal standard of 1.5. In the Institute's test, the xB's roof withstood a force equal to 6.8 times the car's weight. The Corolla's roof supported 5.1 times the car's weight.
In the Institute's roof strength test, a metal plate is pushed against one side of a roof at a constant speed. To earn a good rating, the roof must withstand a force of 4 times the vehicle's weight before reaching 5 inches of crush. This is called a strength-to-weight ratio. For an acceptable rating, the minimum required strength-to-weight ratio is 3.25. A marginal rating value is 2.5. Anything lower than that is poor.
This test method is the same one that has been used for testing under the federal roof strength regulation since 1973, but with much higher requirements. Vehicles only need a strength-to-weight ratio of 1.5 to meet the federal regulation.
While the actual roof strengths of vehicles may surpass this minimum level by a large amount, this information has not been available to consumers. Institute research has found that a vehicle with a roof strength-to-weight ratio of 4.0 has an estimated 50 percent reduction in the risk of serious and fatal injury in single-vehicle rollover crashes compared with the minimum level of 1.5.
"Top Safety Pick recognizes the vehicles that afford buyers the best overall protection in common crashes," says Institute president Adrian Lund. "With more top performers, there's no reason to buy a small car with less than stellar crash test ratings."
