|Summary of the small car crash testing. Click to enlarge.|
For the first time, the Insurance Institute for Highway Safety (IIHS) has tested the smallest vehicles sold in the US market, which gain popularity as fuel prices rise.
Crash test results indicate which vehicles in each weight category afford the best protection in real-world crashes, and this round of tests reveals big differences among the smallest cars, according to IIHS. The Nissan Versa earns good ratings in all three tests—front, side, and rear crashes. Two other cars earn good ratings in front and side but not rear tests.
|Crash deaths in lighter-weight vehicles are higher. Click to enlarge.|
Data from real crashes indicates that driver death rates in the smallest cars are higher than in any other vehicle category, and more than double the death rates in midsize and large cars. Death rates in single-vehicle crashes also are higher in smaller vehicles than in bigger ones.
People traveling in small, light cars are at a disadvantage, especially when they collide with bigger, heavier vehicles.—Adrian Lund, IIHS President
The smallest cars in the US weigh about 2,500 pounds or less; midsize cars weigh about 800 pounds more than a minicar; and a midsize SUV weighs 4,000 pounds or more, exceeding the weight of a minicar by at least 60 percent. In every vehicle category (car, SUV, or pickup truck), the risk of crash death is higher in the smaller, lighter models.
Despite the safety trade-off, more consumers are buying minicars. This is why we tested them. We want consumers to use the ratings to choose the most crashworthy designs among the smallest cars.—Adrian Lund
The Nissan Versa—the largest of the lot tested in this round—is the only car to earn the highest rating of good in all three tests. In the frontal test, its structure held up well, minimizing intrusion into the space around the driver dummy. Most injury measures were low. In the side test, the standard curtain-style airbags prevented contact between the striking barrier and the heads of the crash test dummies (Nissan is modifying the side airbags in cars built after November 2006 to improve protection in side impacts).
The Institute’s side test is especially challenging for small cars because the barrier that strikes the test vehicle represents the front end of a pickup truck or SUV. Side airbags designed for head protection are crucial because the barrier crashes into the side of the car right at the head level of the two dummies that are positioned in the driver seat and in the rear seat behind the driver.
The Honda Fit with standard side airbags and the Toyota Yaris equipped with optional side airbags also earn good ratings in front and side tests. However, rear protection isn’t rated good. The Yaris is rated marginal for occupant protection in rear impacts, and the Fit’s rear rating is poor.
The Institute conducted two frontal tests of the Fit. In the first test the frontal airbag deployed too early, allowing high forces on the driver dummy’s head. Honda is modifying the airbags in cars built after November 2006 and says it will recall cars built earlier. In the second test of a Fit with the design change, the frontal airbag deployed properly, and injury measures recorded on the dummy’s head were low. The published rating is for vehicles with the design change.
The Hyundai Accent, Scion xB, and the Toyota Yaris without its optional side airbags earn poor ratings in the side test. The Chevrolet Aveo is marginal. The Accent and Aveo didn’t perform well even though they have standard side airbags. The Aveo’s front seat-mounted side airbags did a good job of protecting the driver dummy’s head, but this car’s structural performance was marginal. Intrusion into the occupant compartment led to high forces on the driver dummy’s pelvis. There’s no side airbag protection for rear-seat passengers, and the barrier struck the dummy’s head.
The Accent’s structural performance in the side test also was marginal. Curtain-style airbags in front and rear seats provided good head protection, but measures recorded elsewhere on the driver dummy indicate a motorist in a similar real-world crash would be likely to sustain internal organ injuries, broken ribs, and a fractured pelvis.
Overall the Accent is the lowest rated car in this group. The rank order takes into account all three ratings (front, side, and rear).
Another poor performer in the side test is the Scion xB. Side airbags aren’t available, and the xB’s side structure didn’t do a good job of resisting intrusion during the impact. The barrier intruded into the car and struck the driver dummy’s head. Measures indicate the likelihood of brain injuries, serious neck injuries, and a fractured pelvis in a real-world crash of similar severity.
The seat/head restraints in many cars still don’t provide adequate protection for most people in rear-end crashes, according to IIHS. Every model except the Versa earns a low rating of marginal or poor.
You don’t have to buy the smallest, lightest car to get one that’s easy on fuel consumption. Models including the Honda Civic, not even the hybrid version, and Toyota Corolla are bigger than the minicars we tested and weigh more, so we would expect better occupant protection in serious crashes. At the same time, these and other small car models get nearly as good fuel economy as minicars.—Adrian Lund
The Institute’s frontal crashworthiness evaluations are based on results of 40 mph frontal offset crash tests. Each vehicle’s overall evaluation is based on measurements of intrusion into the occupant compartment, injury measures recorded on a Hybrid III dummy in the driver seat, and analysis of slow-motion film to assess how well the restraint system controlled dummy movement during the test.
Side evaluations are based on performance in a crash test in which the side of a vehicle is struck by a barrier moving at 31 mph. The barrier represents the front end of a pickup or SUV. Ratings reflect injury measures recorded on two instrumented SID-IIs dummies, assessment of head protection countermeasures, and the vehicle's structural performance during the impact.
Injury measures obtained from the two dummies, one in the driver seat and the other in the back seat behind the driver, are used to determine the likelihood that a driver and/or passenger in a real-world crash would have sustained serious injury to various parts of the body. The movements and contacts of the dummies’ heads during the crash also are evaluated. Structural performance is based on measurements indicating the amount of B-pillar intrusion into the occupant compartment.
Rear crash protection is rated according to a two-step procedure. Starting points for the ratings are measurements of head restraint geometry—the height of a restraint and its horizontal distance behind the back of the head of an average-size man. Seats with good or acceptable restraint geometry are tested dynamically using a dummy that measures forces on the neck. This test simulates a collision in which a stationary vehicle is struck in the rear at 20 mph.