Small-overlap front crash tests and inadequate headlights tripped up half of the six large sedans recently tested by the Insurance Institute for Highway Safety (IIHS). The Lincoln Continental, the Mercedes-Benz E-class, and the Toyota Avalon were given the group’s highest rating of Top Safety Pick+, while the Chevrolet Impala, the Ford Taurus, and the Tesla Model S failed to achieve either that top rating or the next-tier Top Safety Pick status.
The latter three cars earned Acceptable ratings in the small-overlap front crash test, and their headlights were all rated Poor. The small-overlap test is meant to simulate what happens when the front corner of a vehicle hits a rigid object such as a tree or a utility pole at 40 miles per hour. The cars scored Good ratings in all other crash tests. Some of the issues with each:
Chevrolet Impala

Although it was last tested when it was redesigned in 2014, the Chevrolet Impala had not yet been put through the IIHS small-overlap test, which began in 2012. The Impala was given only an Acceptable rating in the test because the crash-test dummy’s head slid off to the left side, leaving it partly unprotected. However, IIHS said measurements taken from the dummy showed a low risk of any significant injuries. The Impala’s optional front crash-prevention system was deemed Superior, helping the car to avoid a 12-mph crash and reducing its speed by an average of 10 mph in a 25-mph crash test.
Ford Taurus

The Ford Taur...