Holden Barina poor roof crush test

The Chevrolet Aveo sedan - the North American version of Holden's light car - has ranked poorly in the latest US roof crush test conducted by the Insurance Institute for Highway Safety.

The Smart ForTwo earned the highest rating of good compared with acceptable for the Honda Jazz, Hyundai Accent, Mini Cooper, and Toyota Yaris. The Aveo was marginal. It is the second time the safety spotlight has shone on the small Holden.

In the first round of ANCAP testing it rated two stars. But the latest model is a four-star car, getting a stronger body and B-pillars and standard side airbags. It uses more high-strength steel to boost impact protection.

Under the IIHS roof crush test, vehicles’ roofs must be twice as strong as the current minimum US federal safety standard to receive a good rating. The ratings are part of new roof strength testing program, adding to consumer information already gathered for front, side, and rear crashworthiness.

The institute's front and side crash test protocols are similar to the European New Car Assessment Program. Institute president, Adrian Lund, expects the roof crush test to drive improved rollover crash protection. "In the same way our frontal offest and side test have led to better occupant protection in these kinds of crashes," he says.

There has been a big improvement in roof structures over the past few years as carmakers make stronger bodies to earn better IIHS and EuroNCAP crash ratings. Strong A and B pillars help prevent intrusion and also strengthen the roof.

"Small cars should have an easier time with the roof strength test," Lund says. "Their light weight means their roofs don't have to work as hard to keep the structure around the occupants intact in a rollover."

In the US test, a metal plate is pushed against one side of a roof at a constant speed. To earn a good rating, a roof must withstand a force of four times the car's weight before reaching a depth of 125mm. The Smart withstood a force of 5.4 times its weight. The Barina withstood a force of just over three times its weight.