Insurance Institute Assesses Bumper Damage in Crash Tests
ARLINGTON, Va. --- The Insurance Institute for Highway Safety has released the first results of new tests that assess how well bumpers protect vehicles from expensive damage in everyday fender-benders. Only three midsize cars among 17 the Institute tested --— the Mitsubishi Galant, Toyota Camry, and Mazda 6 --— withstood four bumper tests with $1,500 damage or less in each test.
Some cars sustained more than $4,500 damage in just one of the four tests, and two cars rang up more than $9,000 total damage.
"Our tests measure how well bumpers protect cars from damage in everyday bumps," said Institute President Adrian Lund. "The whole purpose of bumpers is to keep damage away from headlights, hoods, and other parts that are expensive to repair, but this purpose was accomplished in only two of the 68 tests we conducted. In the rest, what we found is that bumpers aren't up to the job."
The new tests reflect the kinds of front and rear impacts that are common in the real world. Insurance claims of $4,500 or less for damage in these crashes total more than $6 billion each year.
The Institute began conducting low-speed crash tests at 5 mph into a flat barrier in 1969. These tests led to the first federal bumper rules for cars, which required the bumpers to resist damage in impacts up to 5 mph. These requirements eventually were rolled back by the Reagan Administration in 1982.
But recent research shows that some of the most costly low-speed crash damage occurs when vehicle bumpers slide under or over each other. This happens because the bumpers on colliding vehicles don't line up, and braking before the impact can lower the front end of a striking vehicle just before it hits the other vehicle. Under- and override often result in damage to vehicle grilles, headlights, hoods and fenders.
The Institute's old flat-barrier tests were good indicators of bumper strength, but they didn't assess over- or underride. Vehicles with comparatively good performances in these tests still sustained costly damage in real collisions. The Institute's new series of tests comes closer to matching the damage that occurs in real-world impacts. Each car is run into a barrier designed to mimic the design of a car bumper. The steel barrier's plastic absorber and flexible cover simulate typical cars' energy absorbers and plastic bumper covers.
The four tests included front and rear full-width impacts at 6 mph and front and rear corner impacts at 3 mph. The barrier is 18 inches off the ground in the full-width tests and 16 inches from ground in the corner impacts. These heights are designed to drive bumper improvements and lead to better protection from damage in a range of real-world crashes. In developmental tests, these configurations produced the kinds and amounts of damage that commonly occur in low-speed collisions.
"We don't want the automakers to change bumper heights just to get good performance in our tests," Lund explained. "We want car bumpers to resist damage in real crashes with other cars as well as with higher-riding SUVs and pickups, so we revamped our tests to reflect such crashes. In particular, we want to encourage automakers to use bumpers with energy-absorbing bars that extend farther into vehicle corners to reduce damage to headlights and other critical and costly equipment. We want car bumpers that are taller so they engage the bumpers on SUVs and pickups instead of underriding them."
Many bumpers aren't high enough or tall enough to take the hit in crashes between cars and SUVs or pickups, according to the Institute. Even when bumpers line up with those on other vehicles reasonably well, many don't stay engaged with the other bumpers in collisions or can't absorb the energy of even a minor bump. This means expensive car body parts sustain most of the damage.
"The cars with the lowest repair bills after our new bumper tests still sustained much more damage than they should have in some of the tests," Lund said. "We got crumpled grilles and headlights plus buckled fenders in impacts at speeds equivalent to an average person walking fast."
The full-front test represents a common situation where a car hits the rear of another vehicle that has stopped in traffic. In this test, the bumpers on only four cars --— the Galant, Camry, Mazda 6, and Saturn AURA --— stayed engaged with the test barrier instead of going under or over it. The result was lower damage totals than other cars in the same test. Damage to three of these four cars totaled less than $1,000, and the AURA was the only car among the 17 tested to limit damage to the bumper itself in the full-front test without getting into the car body.
"This test should be easy if cars had well-designed bumpers because the energy of the crash can be spread across the whole front of the car. Instead, some cars sustained more damage in this test than the other three," Lund said.
Results were similar in the rear tests. Reducing the damage required the bumpers to engage the barrier and absorb the energy of the impact, but this mostly didn't happen. A relatively good performer in the full-rear test was the Hyundai Sonata. Its bumper did engage the barrier, and most of the damage was limited to the bumper (minor repair of the rear body panel also was required). Total damage came to $739.
Good bumper performance requires not only engagement with the test barrier but also strength sufficient to absorb the energy of a low-speed crash. Hyundai engineers strengthened the Sonata's bumper after learning about the Institute's upcoming series of new tests.
Bumpers used to do a better job of resisting damage in minor impacts, the Institute said. Under federal requirements that were in effect until 1982, car bumpers had to keep damage away from vehicle safety equipment and sheet metal parts in collisions at speeds up to 5 mph. Even damage to the bumpers themselves was limited. But since 1982 the test speed under the federal standard has been cut in half. It's now 2.5 mph.