The Smart car is getting a lot of attention for its small size and style, and now it’s earning impressive crash test ratings. The Insurance Institute for Highway Safety (IIHS) in Arlington, Virgina, has given the Snmart Fortwo — the smallest car for sale in the United States — the top rating of good for front and side crash protection.
The Fortwo’s seat/head restraints earned the second highest rating of acceptable for protection against whiplash in rear impacts.
Smart Fortwo is classified a microcar, meaning it’s smaller even than minicars. Weighing about 1,800 pounds, the Smart is more than three feet shorter and almost 700 pounds lighter than a Mini Cooper.
It weighs about a third as much as one of the heaviest vehicles the Institute has tested, the BMW X5, a midsize SUV.
As the price of fuel climbs and tougher federal fuel economy requirements kick in, auto companies are expected to introduce more small vehicles to the market. The Smart is the smallest car the Institute ever has tested.
The IIHS test results generally demonstrate how well vehicles stack up against others of similar size and weight. Frontal ratings can’t be compared across weight classes, meaning a small car that earns a good rating isn’t safer than a large car that’s rated less than good.
The Smart has a crashworthy design for its size and is equipped with the latest safety gear, which is especially important in a small car. This vehicle’s standard equipment includes seat-mounted combination side airbags designed to protect both the heads and chests of the driver and passenger. Also standard is electronic stability control (ESC), called electronic stability program in the Smart. ESC helps drivers maintain control during emergency maneuvers or on slippery roads. It engages automatically when it senses vehicle instability, and Institute research has found that ESC lowers the risk of fatal single-vehicle crashes by about half.
Restraints do more of the work in frontal crashes: The Smart mostly lacks a front-end crush zone, which is a key component in reducing injury risk in serious]]> frontal crashes. Typically, front-end structures are designed to crush and absorb crash energy, allowing occupant compartments to slow more gradually, ideally with little or no intrusion into drivers’ survival space. Then a vehicle’s safety belts and airbags slow occupants further and are designed to spread crash forces more evenly across people’s bodies. The longer the front-end crush structure of a vehicle, the more gently occupants are slowed and thus protected from injury.
To compensate for the lack of front-end crush space, the Smart’s restraint system does more of the work of absorbing energy as occupants “ride down” a crash.
A stiff side structure and standard side airbags contributed to the Smart’s good rating in the side test, which replicates a crash with a pickup truck or SUV. Injury forces recorded on the driver dummy’s head, neck, torso, pelvis, and left leg all were low. However, the driver door unlatched during the crash. This confirms a finding of the National Highway Traffic Safety Administration’s side test of a Smart released last month.
The Institute downgraded the Smart’s structural rating from good to acceptable, but the opening didn’t appear to affect dummy movement during the test, and injury measures on the driver dummy were low.
The Institute’s frontal crashworthiness evaluation is based on results of a 40 mph frontal offset crash test. A 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.
The side evaluation is 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 an instrumented SID-IIs dummy in the driver seat, assessment of head protection countermeasures, and the vehicle’s structural performance during the impact.