Toyota will be pleased with the crash performance of its tiny iQ under the new Euro NCAP impact test procedure. The diminutive city car almost put its much bigger brother, the new Avensis, to shame.

The iQ scored the maximum five stars overall, with a score of 91% for front-seat passenger protection. The much larger Avensis also scored five stars overall and 90% for adult protection.

The tests showed that small cars don’t have to perform poorly in impact tests – Ford was no doubt disappointed with the four stars notched up by its new Ka under the older NCAP testing regime late last year.

There’s not much room in the back of an iQ, so it’s no surprise that the scores for rear-seat child protection were not so great – 71% for the iQ versus 86% for the Avensis. Incidentally, it looks like the tiny proportions of the iQ caused headaches for the testers at Euro NCAP. In the crash test pictures and footage you can see that the test measurement equipment wouldn’t fit in the boot and had to be mounted on a lashed-up shelf bolted to the rear of the car.

Of course there is an elephant in the room where crash tests are concerned – the barrier tests effectively simulate an impact with an equal-sized car. When driving a tiddler, however, you are much more likely to meet something bigger coming the other way, with more momentum than you. The basic physics of force equalling mass times acceleration dictates that the lighter car will undergo more severe deceleration in a head-on smash, with an increased likelihood of injuries as a result. As a consequence, crash test data can’t really be used to assess the relative safety of differently sized cars in the real world.

Driving carefully, maintaining a good gap, not driving when tired and driving a bit more slowly can all help increase your safety, no matter what size of car you choose.