WASHINGTON -- The 2011 Chevrolet Volt and Nissan Leaf electric cars won the highest safety ratings in crash tests performed by the Insurance Institute for Highway Safety, putting them in the top 57 percent of models tested so far this year.
About 80 of 140 vehicles tested among 2011-2012 models have received the Institute's "top safety pick," the group's award for state-of-the-art crash protection that exceeds federal safety rules, Institute spokesman Russ Rader said.
The Volt and Leaf received a "good" rating -- the highest of four rankings -- on each of four crash tests, said the Institute, which is funded by auto insurers including State Farm, All-State and Geico.
The tests involve front, side and rear collisions with another vehicle, and a rollover crash.
"What explains the Volt's and the Leaf's performance is the crash engineering that went into their development," Rader said.
The vehicles were engineered with a strong "crumple zone" between the bumper and windshield to maximize protection during a front collision. They also feature strong pillars between the front and rear doors to offer enhanced protection in the event of side crashes, he said.
The ratings are based on a vehicle's structural performance and injuries to crash-test dummies in the model being examined. Any damage to the other test vehicle or its occupants is not considered, Rader said.
Most 2011-2012 vehicles tested have received the highest safety award because "manufacturers have been stepping up to meet" increasingly tougher crash protection criteria, he said.
The performance of the Volt and Leaf, which are classified as small cars, can also be attributed to the weight of their battery packs, he said.
"When they collide with something bigger and heavier like a truck or SUV, they have an advantage over other small cars," Rader said.
The Institute tested the Volt and Leaf between January and March.