Understanding NHTSA Ratings NHTSA performs full frontal and side-impact crash tests, and provides rollover ratings using a calculation of the vehicle’s center of gravity and its track width combined with the vehicle’s performance in a quick-maneuver driving test.

NHTSA performs full frontal crash tests, where vehicles are fitted with crash dummies and driven into a wall at 35 mph, and side-impact tests, where a 3,015-pound sled is driven into the side of a parked test car at 38.5 mph. Scores for crashworthiness are awarded with one to five stars, with one star for a frontal crash suggesting at least a 46 percent chance or greater of serious injury, while five stars suggests an injury risk of 10 percent or less.

Ratings for the side impact test are slightly different: one star represents at least a twenty-six percent or greater chance of injury and five stars represents a risk of five percent or less. NHTSA also provides rollover ratings, combining a calculation of the vehicle’s center of gravity and its track width with the vehicle’s performance in a quick-maneuver driving test.

In some cases, when something unexpected occurs during a test, the star rating won’t necessarily change, but NHTSA will attach a “safety concern” notice to the vehicle in addition to its final rating.