DETROIT  — The 2014 Chevrolet Impala was the only non-luxury car to earn the highest safety rating in new tests of high-tech crash prevention systems.

The Insurance Institute for Highway Safety tested cars equipped with collision warning and automatic braking systems. It gave a “superior” rating to cars that both warned the driver of a potential collision and applied the automatic brakes to significantly slow the cars.

The BMW 5 Series, BMW X5, Mercedes-Benz E-Class, Buick Regal, Cadillac CTS, Cadillac XTS and 2015 Hyundai Genesis also earned “superior” ratings in the test results released Thursday.

Collision warning and automatic braking systems use radars, cameras and lasers to determine if a vehicle is getting too close to the car in front of it. Most of the systems warn the driver — audibly, with vibrations in the seat, or both — and prepare the brakes to maximize their effect when the driver presses them.

In some cases, the vehicles brake themselves. That action may not prevent a crash, the institute said, but reducing the speed before the car hits something can help make crashes — and injuries — less severe.