The Citroen Nemo, a pint-sized minivan sold in Europe, but not the U.S., rolled over onto its roof during a routine avoidance-maneuver test conducted in Germany this month.
The rollover demonstrated the critical importance of electronic stability control (ESC), which the Nemo lacks, even as an option. The Fiat Quobo, a virtually identical vehicle that did have ESC, was tested at the same time and showed no signs of tipping. Called variously the moose or elk test, the maneuver was a standard double-lane-change trial that’s quite similar to the avoidance maneuver Consumer Reports uses in evaluating every car we test. This was the same test that caused the small Mercedes-Benz A-Class to flip over in 1997, paving the way for ESC to be added to small vehicles such as Mercedes’ Smart Car.
In a course marked off with traffic cones, the avoidance maneuver gauges how a car behaves if the driver must suddenly swerve around an obstacle in the road and then regain its original path. The test in which the Nemo rolled over was co-sponsored by Britain’s Which? magazine, the UK’s version of Consumer Reports, and conducted by the German Automobile Association (ADAC).
Besides its lack of an ESC system, the Nemo’s short wheelbase and tall body also played a role in allowing a rollover. Those same attributes also make small SUVs and compact pickups more prone to rollovers than vehicles closer to the ground. In this demonstration it appears that ESC alone made the difference between a safe transit and a life-threatening disaster.
ESC is designed to prevent a vehicle from sliding by selectively braking one or more wheels, and sometimes throttling back engine power, to help keep a vehicle on its intended path. ESC is now standard or optional on nearly all new vehicles sold in the US and will be mandatory on all 2012 model-year vehicles.
To find out which U.S. models have ESC and other important safety features, see our safety comparison chart. For more on vehicle safety, see our safety guide.
— Gordon Hard