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Status Report, Vol. 43, No. 5 | July 1, 2008 Subscribe

Bumper rules should extend to light trucks, Institute tells NHTSA

Fitting their gear into this SUV is a problem they can solve. A problem they probably don't even know about is the bumper. It's too high, and it's too flimsy. To address these shortcomings, the Institute has petitioned the federal government to regulate the bumpers on light trucks (SUVs, pickups, and vans) just as it regulates those on cars. In fact, apply the same bumper rules to all different kinds of passenger vehicles, the Institute says. After all, they're sharing the road, and there's no reason anymore, if there ever was a good reason, not to apply bumper rules across the board to cars and light trucks alike.

Federal rules in effect since the 1970s specify a zone for the heights of car bumpers and limit the amount of damage that's allowed beyond a car's bumper system in a low-speed collision. The idea is to ensure that the bumpers on colliding cars engage, absorb most of the energy of the impact, and thus keep damage away from expensive-to-repair parts like fenders, grilles, and lights.

What the Institute is asking

Car bumper rules don't apply to light trucks. 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. You can't have it both ways — good bumpers and light truck utility — the National Highway Traffic Safety Administration (NHTSA) says. Given this choice, the agency has sided with utility. It has refused to regulate light truck bumpers, let alone require bumpers that meet the same standards as those on cars.

The Institute counters that this isn't an either/or choice. Putting damage-resistant bumpers on light trucks needn't compromise utility. So the Institute is petitioning NHTSA to apply the same bumper rules to light trucks as cars. To buttress this request, the Institute cites new crash tests involving an SUV with bumpers that line up reasonably well with those on cars. This SUV does a better job than three others of resisting damage in low-speed crashes and minimizing damage to the vehicles with which it collides.

"There's no evidence that the relatively effective bumpers on this SUV compromise its off-road performance or its utility at loading ramps," says Institute senior vice president Joe Nolan. "We hope NHTSA considers this example, takes a hard look at the high costs consumers are paying to fix the damage that occurs day in and day out in low-speed collisions on U.S. roads, and then takes action to require light trucks to meet the same bumper requirements as cars."

New crash-test results

As part of the petition to NHTSA, the Institute details the results of low-speed crash tests involving four midsize SUVs striking the backs of stationary midsize cars, all Hyundai Sonatas. The front bumpers on 3 of the 4 SUVs — Hummer H3, Jeep Grand Cherokee, and Mitsubishi Endeavor — are higher than the 16 to 20 inches from the ground that's specified in federal regulations for the bumpers on cars. They're so high that all 3 SUVs overrode the Sonatas' bumpers in the Institute's 10 mph front-into-rear tests.

The result was damage to the Sonatas ranging from $3,891 to $4,737. Even the SUVs sustained more than $1,000 damage apiece. Such damage included broken taillights on the Sonata and cracked headlights on 2 of the 3 SUVs. Other safety-related components also were compromised.

Results were different for the fourth SUV the Institute tested, a Ford Explorer. It 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 4 SUVs, the H3. None of the damage to either the Explorer or Sonata involved safety-related components.

These results are consistent with those of tests the Institute conducted in 2004, which involved paired cars and SUVs from the same vehicle manufacturers (see "Huge cost of bumper mismatch: Cars and SUVs don't line up in crashes," Sept. 13, 2004). Once again, Fords turned in the best performances. When an Explorer hit a Taurus at 10 mph and then the Taurus hit the SUV at the same speed, damage was less than when 4 other pairs of cars and SUVs were tested.

Experience in real-world crashes is consistent. The 3 poor-performing SUVs in 2008 tests by the Institute had some of the highest insurance losses under property damage liability coverage during 2005-07. That is, they inflicted excess damage on the vehicles with which they collided. In contrast is the Explorer with its lower-than-average losses under the same insurance coverage during the same years.

"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," Nolan explains. Once engaged, the bumpers absorb a lot of the energy of the impact, protecting the vehicles from damage to sheet metal and safety parts that are expensive to repair.

Ford shows how to build an SUV with a lower bumper.


The Explorer's front bumper lines up with the rear bumper on the Hyundai Sonata.


Repair costs after the Explorer struck the back of a Sonata: $1,520 car and $866 SUV.

Other SUVs don't measure up when it comes to their bumpers.


Repair costs after the Mitsubishi Endeavor struck the back of a Sonata: $3,891 car and $1,129 SUV.


Repair costs after the Jeep Grand Cherokee struck the back of a Sonata:$4,633 car and $1,324 SUV.


Repair costs after the Hummer H3 struck the back of a Sonata:$4,737 car and $1,700 SUV.

These examples illustrate why NHTSA should go ahead and require light trucks to meet the same bumper requirements as cars. The Endeavor, Grand Cherokee and H3 show why new rules are needed for light trucks. The Explorer shows that applying the rules to light trucks won't compromise their utility. This is the reason NHTSA has cited for not applying uniform requirements to the bumpers on all kinds of passenger vehicles.

Survey of damage in real crashes

More evidence of the need for light truck bumpers that are as good as, or better than, the Explorer's comes from Institute surveys conducted during 2001-02 of damage patterns among vehicles at drive-in insurance claims centers. The cars at these centers were much more likely to exhibit evidence of underride if they collided with light trucks than if the collisions involved other cars.

Two of every 3 cars involved in collisions with SUVs and more than half of the cars that collided with pickup trucks underrode them. This compares with underride in only about 20-30 percent of crashes involving a car and either another car or a minivan. Damage repair costs also were higher for the cars that showed evidence of underriding.

Utility versus bumper height

The Explorer's performance in the Institute's 2004 and 2008 bumper tests isn't the only evidence that utilitarian vehicles can be equipped with car-compatible bumpers without compromising their usefulness for work purposes. In fact, light trucks used to have lower bumpers.

Those on models of the 1970-80s measured 19 inches from the ground or lower, and they still were used off road and at loading ramps. In contrast, many of today's light truck bumpers are measured at more than 20 inches tall.

"It's only an inch or so of difference in bumper height," Nolan points out, "but it's an important inch when you consider that car bumper heights have to be 16 to 20 inches from the ground. That's the federal rule, so anything taller than 20 inches won't line up with a car bumper — and most light truck bumpers today don't."

No more excuses

Even if NHTSA sticks to its stated policy "not to regulate bumper performance or elevation of these vehicles because of potential compromise to the[ir] utility," there's still room to apply car bumper standards to these vehicles. Technological means of raising and lowering ride height open up new options. Some Land Rover and Audi models, for example, have electronic air suspension systems that motorists can switch on to raise their vehicles for off-road use and lower them again when they go back on road to make the bumpers more compatible with those on cars.

If NHTSA isn't convinced by all this evidence of the need to regulate the bumpers on light trucks, the Institute points to yet another reason for such regulations. At NHTSA's own behest, auto manufacturers have been working since 2003 to improve the compatibility between cars and light trucks in front and side collisions that occur at higher speeds (see "Automakers' efforts reduce mismatch between cars and light trucks," Jan 28, 2006). This cooperative effort continues apace, and many light trucks already meet the design criteria the auto manufacturers agreed on to reduce injuries to people in cars that are struck by the heavier, higher riding passenger vehicles.

All light trucks built after Sept. 1, 2009, will meet the criteria to improve compatibility in serious crashes. Addressing bumper mismatch would help this effort.

"It's a win-win," Nolan says. "One program would complement the other, and the result could be to improve both occupant protection in high-speed crashes and resistance to vehicle damage in collisions at slower speeds. All NHTSA has to do is regulate light truck bumpers."

This isn't the first time NHTSA has been asked for similar action. Twice petitioners have requested light truck bumper regulations, and twice they have been refused, once in 1984 and again in 1991.

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