Subaru and Alfa Romeo were criticised in new Euro NCAP tests that, for the first time, measure effectiveness of cars' electronic stability control systems.
The new stability control tests conducted by Thatcham included a double lane-change manoeuvre at 50mph under the control of a steering robot.
Multiple runs were carried out where the steering angle and input were increased each time. Tests were also conducted on cars where stability control can be switched on or off.
The Berkshire based research centre evaluated more than 40 new models and although all passed the test, Thatcham criticised the location of the stability control button on the Subaru Impreza because it feared the system could be deactivated accidentally by the driver's knee without the driver realising. Alfa's Mito hatchback failed when the car was in the 'Dynamic' setting of its three-mode DNA driver-aid system.
It is the first set of stability control tests for Euro NCAP. Stability control is an active safety system that detects when a car is going out of control and automatically brakes individual wheels in a bid to prevent skidding.
Research by Thatcham has revealed that cars with stability control are 25% less likely to be involved in a fatal accident than those without.
Stability control is not yet mandatory in this country but it is in the US. Estimates suggest that there would be about 380 fewer deaths annually in the UK if every car had stability control.