September 14, 2004


Mismatched bumper heights create high repair costs

Arlington, Virginia – Mismatched bumper heights between cars and SUVs are
responsible for high repair costs in low-speed collisions, reports the U.S.
Institute for Highway Safety.

The Institute tested five pairs of vehicles, each composed of a car and a midsize
SUV from the same manufacturer. The pairs included a Ford Taurus and Explorer, a
Chevrolet Malibu and TrailBlazer, a Dodge Stratus and Jeep Grand Cherokee (both
DaimlerChrysler products), a Nissan Altima and Murano, and a Volvo S40 and XC90.

“We paired vehicles from a single manufacturer because we thought that, at a
minimum, automakers should be paying attention to the compatibility of the bumpers
across their own fleets,” Institute chief operating officer Adrian Lund explains.

In the tests, a car going 10 mph struck the back of its paired SUV, which was
stopped. Then the configuration was reversed, with the SUV striking the back of its
paired car. Results of these low-speed impacts varied widely, from a total of about
(U.S.)$1,250 damage in one test to more than (U.S.)$6,000 damage to the paired
vehicles in two other tests.

In some cases, the low-speed crash damage included major leaks from broken
radiators. In real-world collisions like these, the motorists couldn’t even drive
away. If they did, their vehicles could overheat and the engines could be
permanently damaged. So in addition to paying for costly repairs, the drivers would
face the aggravation of having to get their vehicles towed.

In both car-into-SUV and SUV-into-car tests, the vehicles with the lowest repair
costs, by far, were the Fords. The other pairs of vehicles sustained much more
damage than the Fords, mostly because their bumpers don’t line up. The bumpers on
some vehicle pairs completely bypassed each other in the tests.

“This was the pattern,” Lund points out. “When there was underride and override
between the car and SUV bumpers, that’s when we saw a lot more expensive-to-repair
damage than most people would associate with a 10 mph impact. Bumps at this speed
involving Volvos and DaimlerChryslers produced more than (U.S.)$6,000 damage to the
two vehicles.”

Most of the repair costs from these tests weren’t because a heavy SUV inflicted
damage on a lighter car. The SUVs also sustained expensive damage. Even when one SUV
hit another SUV, the damage was costly.

The Institute conducted another 10 mph crash test to show that the problem isn’t
confined to crashes between cars and SUVs. In this impact, the front of a Toyota
RAV4, a small SUV, hit the back of another RAV4, producing more damage than in any
of the car-into-SUV or SUV-into-car crashes.

“When one RAV4 struck the other, it didn’t engage the rear bumper because this SUV
doesn’t have a rear bumper. Instead the striking RAV4 hit the spare tire mounted on
the tailgate,” Lund says. “This spare tire was the ‘antibumper.’ It didn’t absorb
any energy. It didn’t prevent any damage. In fact, it caused most of the damage to
both vehicles. The spare damaged the hood and grille of the striking RAV4. It also
crushed the tailgate on the struck RAV4.”

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