ARLINGTON, Va. — The Insurance Institute for Highway Safety (IIHS) has petitioned the federal government to regulate the bumpers on light trucks (SUVs, pickups, and vans) just as it regulates those on cars, and the group says the same bumper rules should apply to all kinds of passenger vehicles.

To meet federal rules, car bumpers must be 16 to 20 inches off the ground and limit the amount of damage that can be sustained in a low-speed crash. The idea is to ensure that the bumpers on colliding cars engage, absorbing most of the energy of the impact and keeping damage away from expensive-to-repair parts like fenders, grilles, headlights, and taillights.

IIHS says car bumper rules don't apply to light trucks. In fact, it's still legal to sell these vehicles without any bumpers at all. Federal regulators' longstanding thinking is that requiring light trucks to have bumpers would compromise off-road navigation and make it hard to use these vehicles at loading ramps. The Institute counters that putting damage-resistant bumpers on light trucks needn't compromise utility.

New SUV-to-car crash test results are now available after a series of low-speed crash tests and the Institute details the results in its petition to the National Highway Traffic Safety Administration. The tests involved four midsize SUVs striking the back of a typical midsize car at 10 miles per hour. One of the SUVS — a Ford Explorer — does a better job than three others (Hummer H3, Jeep Grand Cherokee, and Mitsubishi Endeavor) of resisting damage in low-speed crashes and minimizing damage to the vehicles with which it collides.

"One big difference is that the Explorer's bumpers line up pretty well with those on cars, so when this SUV hits a car or a car hits it, the bumpers on both vehicles engage instead of over- and underriding each other," says Institute president Adrian Lund. Once engaged, the bumpers absorb a lot of energy, protecting the vehicles from expensive-to-repair damage to safety-related parts and sheet metal.

"When cars collide with other cars, their bumpers usually line up pretty well," Lund notes. "But in SUV-to-car crashes, the bumpers often don't match up at all, and the result is thousands of dollars of unnecessary damage in low-speed crashes."

The front bumpers on the H3, Grand Cherokee and Endeavor are so high that they overrode the rear bumpers of the stationary Hyundai Sonatas in the Institute tests. Damage to the Sonatas ranged from $3,891 to $4,737. Even the SUVs sustained more than $1,000 damage each. In contrast, the Explorer sustained less than $1,000 damage in the same front-into-rear test, and it inflicted only about one-third as much damage on the Sonata as the worst performer among the four SUVs, the H3.

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