Cars.com's Guide to Interpreting Crash Tests and Rollover Ratings — and Why You Should Care
All vehicles sold in the United States must pass Federal Motor Vehicle Safety Standards in the form of 30-mph frontal and 33.5-mph side-impact compliance crash tests, but the relative safety of all vehicles above this minimum standard varies greatly.
The most important things to know about crash tests:
- Not all results can be compared.
- Crash tests differ by agency.
- Side-impact ratings have deficiencies.
- Rollover ratings have shortcomings.
- Some models are not rated.
Model-to-model comparisons of frontal crash ratings are valid only within a vehicle class or between models of comparable weight (within 250 pounds). The test reflects how the vehicle would fare in a collision with another of the same model, not versus a larger or smaller vehicle (or a lower- or higher-riding vehicle). A heavier vehicle would protect its occupants better than a lighter one if all other factors were equal, but they never are. So a large vehicle with a Poor rating is not necessarily safer than a small vehicle with a Good rating. Unfortunately, researchers have not yet devised a reliable method for reporting the effect of size differences on a vehicle's score.
Not all results can be compared
Note: Side-impact crash tests are comparable across classes because the sled that rams the test vehicles is of a consistent size and weight. See the section titled "Side-impact ratings have deficiencies" below.
Crash tests differ by agency
|The Dodge Durango performs well in the NHTSA frontal crash test, earning a double five-star rating.|
Side-impact crash tests currently aren't as telling as we'd like. Though NHTSA has tested more models than IIHS for side-impact protection, we dismiss these tests as inadequate and, arguably, flawed for two reasons:
Side-impact ratings have deficiencies
- The sled employed to "T-bone" the stationary test vehicle has the height and mass of a car, not an SUV or pickup truck. This tends to minimize its intrusion into the cabin — a best-case scenario.
- NHTSA's chance-of-injury data are based on trauma to the test dummies' torsos, not their heads. Occupants' heads are more susceptible to injury in a side impact, and head injuries are more often serious and potentially fatal.
|The sled used in IIHS side-impact crash tests is designed to simulate a collision with a truck or SUV.|