Volt, Leaf earn top IIHS safety marks image

The battery-powered Nissan Leaf and Chevrolet Volt have each earned a “Top Safety Pick” award from the influential Insurance Institute of Highway Safety.

Both earned top safety ratings, an early validation for experts who say automakers do not have to sacrifice safety for better fuel economy, that advanced technologies can achieve both.

Not only did the cars’ battery packs, which weigh more than 400 pounds, prove to be well-protected in the test collisions, but the added weight from the large batteries appears to have worked in the small cars’ favor when it comes to crash safety.

To be designated a top pick, a vehicle must score the highest rating of “good” in front, side and rear crash tests, as well as in a roof-crush test. The institute has awarded the rating to certain gas-electric hybrids in the past, such as the Honda Civic hybrid, but not yet to a plug-in from a major maker.

“It is quite a stellar performance for both vehicles,” said Joe Nolan, the institute’s chief administrative officer.

The automakers were confident that their vehicles would test well. “We approached G.M. and Nissan and asked would they support us and help us acquire the vehicles,” Mr. Nolan said. “They were both very supportive, suggesting they were expecting good results.”

Mr. Nolan said that both automakers “bumped customers off the list” to provide the institute with test vehicles, a strong hint “that they were going to be Top Safety Picks,” he said.