Ever wondered how older cars fare in a crash safety test? Well, researchers at a Swedish non-profit organisation Villaagarnas Riksforbund and insurance company Folksam tested used cars that are just over a decade old to find out just how much age and rust affect used cars, and whether or not the cars’ crashworthiness degrades over a moderate period of time.

The outfit tested multiple cars from two groups: 2004-2008 generation Volkswagen Golf and a 2003-2008 generation Mazda 6, all of which were diagnosed with rust issues. The cars were subjected to front and side impacts according to Euro NCAP standards, and the tests were conducted at Thatcham’s British Crash Laboratory.

The Golf and Mazda 6 were specifically chosen because they represent two distinct segments and both are popular in Europe. More interestingly, the duo are relatively sensitive to rust, some of which have found its way into the crash beams.

Unsurprisingly, the group discovered deterioration in both cars’ crash safety levels. Granted, both the Golf and Mazda 6 are older cars, so they wouldn’t have been put through the more stringent tests that have been put in motion and standardised in recent years. To level the playing field, both cars were tested as per Euro NCAP’s standards of the time.

As the tests show, both cars received a lower rating in comparison to when new. “When the Mazda 6 was tested in the frontal test, the car was deformed so that the driver’s seat ended up leaning against the interior of the car and the crash test dummy hit its head in the B-pillar (the pillar between the doors),” said the organisation.

“At the frontal collision, the crash test dummy was thrown forward towards the airbag, which is released from the steering wheel. Then the crash test dummy rebounded in the B-pillar before going back to the car seat again. If a crash test dummy rebounds into the B-pillar, this is not considered by the Euro NCAP model.”

The same fate befell the Volkswagen Golf as well, as it was found to have lost some of its crashworthiness. However, it’s only down by a single point in comparison to its score when new.

“For the Volkswagen Golf, the grade was reduced according to Euro NCAP’s five-point rating scale from a weak five (33 points) when the car was new to a strong four (32 points),” the researchers said. “But the difference in crash safety was marginal with only one point difference.”

Perhaps the most surprising finding was just how much the Mazda’s crash performance deteriorated due to rust issues. “In the case of Mazda 6, crash safety was significantly impaired. The rating was lowered from a weak four (26 points) when the car was new to a weak three (18 points). According to Folksam, for Mazda 6 there is a 20% higher risk of being killed in a real accident, because of the rust,” explained the researchers.

The research group points out that no two cars’ rust issues are alike, and hence it cannot be said with certainty that another used Mazda 6 with rust problems would have fared the same in these tests. The location of the rust issues matters, but in the case of the Mazda 6 it no longer deformed as designed, thus the degradation of its crashworthiness.

What do you think of this? As usual, comment and watch the videos below to compare how the rusted crash tests fared in comparison with Euro NCAP’s tests.