In a new Insurance Institute for Highway Safety (IIHS) test of forward collision prevention systems, Subaru's system topped all the rest—with a total of 74 different models tested, most with luxury badges.
Under the new protocol, which involves driving a vehicle at speeds of 12 mph and 25 mph into a stationary barrier that simulates the rear of another vehicle, seven models in all earned the highest 'superior' rating: the Cadillac ATS, Cadillac SRX, Mercedes-Benz C-Class, Subaru Legacy, Subaru Outback, Volvo S60, and Volvo XC60.
In the new test, a rating of 'superior' means the vehicle can avoid the crash entirely or substantially reduce speeds. The 'advanced' result means that the vehicle can brake autonomously and can either avoid a crash entirely or significantly reduce speeds in one of the two tests. Meanwhile, the 'basic' rating means the vehicle has a forward collision system that meets minimum federal criteria but fails to brake the car in either situation.
Six models earned the middle 'advanced' rating: the 2014 Acura MDX, Audi A4, Audi Q5, Jeep Grand Cherokee, Lexus ES, and Mazda 6. The IIHS notes that even when not optioned with the so-called Collision Warning with Full Auto Brake and Pedestrian Detection feature, the Volvo S60 and XC60 are the only two models on the market to include autonomous braking in base form and get the 'advanced' rating.
The IIHS limited the upper test speed to 25 mph because any higher speed would have extensively damaged the vehicles.
Such systems are not created equal
There were some disappointments and surprises in the new testing. For instance, the system that BMW offers—tested in the 3-Series—was given only the 'basic' rating because, as the IIHS points out, it will only brake if it detects a moving car up ahead suddenly stop; it won't perform any braking action for stopped vehicles ahead.
The Institute had even sharper criticism about the Toyota Prius V. Toyota claims that the forward collision system in that car has autobrake, but testing showed “minimal braking” and said that it currently even failed to meet federal standards for such a feature.