Recent crash tests conducted by the Insurance Institute for Highway Safety highlight an important principle to keep in mind when comparing crash-test results: Bigger is better.
The insurance institute, which rates vehicles on a scale of good, acceptable, marginal and poor, conducted three frontal crash tests this year. Each involved crashing a very small car into a midsize car from the same manufacturer to show how larger and heavier vehicles do a better job of protecting occupants in frontal collisions.
Whereas the very small cars did well on earlier frontal crash tests, they did not do so well in these crashes with slightly larger vehicles.
The institute, a Virginia-based group funded by the insurance industry, crashed Daimler’s Smart ForTwo into a Mercedes-Benz C-Class, a Honda Fit into a Honda Accord and a Toyota Yaris into a Toyota Camry.
Everyone pretty much knows they wouldn’t fare well if their Smart collided with a Hummer; but the institute wanted to use midsize cars in these tests to show that very small cars will be the losers in crashes with vehicles just a little bit bigger than them.
The vehicles crash-tested received earlier ratings of “good” against vehicles in the same size class from the insurance institute on its standard offset crash tests. These new crash tests, however, were far different - so different that the ForTwo, Fit and Yaris got ratings of “poor.”
In the standard offset frontal crash tests, about 40 percent of the vehicle’s front on the driver’s side strikes a deformable barrier at 40 mph. The institute says this duplicates two vehicles of similar size and weight, each traveling about 40 mph, colliding. Therefore, test results can be compared only among vehicles of similar weight. That is how the Fit, Smart and Yaris got their “good” ratings.
Although the federal government’s frontal crash tests are conducted somewhat differently, the same caveat applies. In the government’s tests, a vehicle is crashed head-on into a fixed barrier at 35 mph. Again, this is the equivalent to a head-on collision between two vehicles of similar weights. (Side crash-test results are different, and those results can be applied across classes of vehicles).
In these new tests, instead of crashing into a deformable barrier, both vehicles crashed into each other (still in the offset position), each traveling about 40 mph.
Some of the reasons for the Fit’s “poor” ratings involved “extensive” intrusion of the Accord into the Fit’s occupant compartment, which meant a high risk of leg injury. Also, the head of the crash dummy in the Fit struck the steering wheel through the airbag.
The Smart became airborne and spun around 450 degrees after striking the front of the C-Class. As a result, the dummy showed “excessive” movement during the rebound and the instrument panel and steering wheel were shoved up and toward the dummy.
The door of the Yaris was largely torn away and the steering wheel moved “excessively.” Although the heads of the dummies in both the Yaris and Camry struck the steering wheels through the airbags, only in the Yaris were the head-injury measurements severe enough to rate a “poor.”
Keep in mind that the laws of physics will always apply, and when you are checking out crash-test ratings before you buy a vehicle, frontal-crash test results apply only to vehicles of the same weight. As insurance institute President Adrian Lund says, “All things being equal in safety, bigger and heavier is always better.”
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