The problem of mismatched bumpers on cars and SUVs could be solved with some simple modifications, saving consumers thousands of dollars on repairs after low-speed collisions, Institute tests show.
In 2010, a series of low-speed tests involving SUVs and cars highlighted the expensive damage that results when bumpers don't line up (see "Bumper mismatch contributes to pricey damage," Dec. 2, 2010). Seven pairs of cars and SUVs from the same manufacturers were crashed into each other. Damage to both vehicles in each of the 10 mph collisions ranged from about $3,000 to nearly $10,000.
Now the Institute has teamed up with Tech-Cor, Allstate's auto-repair research center, to show how lowering SUV bumpers a few inches can reduce crash damage. Engineers picked 2 of the previously tested SUVs and modified their bumpers. The crashes were then repeated, resulting in big reductions in repair costs for both cars. In the case of a Ford Focus that was crashed into the back of a Ford Escape, the damage plummeted 84 percent to less than $1,000 after the Escape's rear bumper was lowered.
Bumpers generally consist of a reinforcement bar under a plastic cover. When it comes to limiting crash damage, it's what's hidden under the plastic that counts, and sometimes there isn't much. A federal standard requires cars to have bumpers that provide protection over a zone 16 to 20 inches off the ground. There are no such requirements for SUVs, pickups, or minivans. As a result, some of them have flimsy bumpers, and many others have bumpers much higher off the ground than those of cars.
The result is high repair costs for even minor crashes. When bumpers work as intended, they absorb most of the energy in a low-speed crash. When they don't line up, the vehicle body bears the brunt of the crash energy. Damage to headlights, grilles, radiators, and other parts adds up to big bills.
In the 2010 tests, the crash of the Focus into the Escape resulted in one of the highest damage totals. The lower edge of the Escape's rear bumper is 23 inches off the ground — the highest of all the SUVs tested — and the Focus' front bumper missed it by more than an inch. The result was that the Focus went under the Escape and ended up needing a new hood, headlights, air-conditioning condenser, and other parts for a total of $5,203. The Escape wasn't unscathed, either, with $2,208 worth of damage.
Crash damage before modification
Crash damage before modification
SUV/car test damage with original equipment and lowered SUV bumpers
Improving the placement of the Escape's rear bumper was straightforward. Tech-Cor engineers added bumper brackets from another SUV to the existing rear frame, then attached the bumper bar, bringing it down 3½ inches from its original location. When the vehicles were crashed again, the only damage to the Focus was to the bumper cover and grille — an $853 repair job. The damage to the Escape fell slightly as well, to $2,070.
The other SUV selected for modification was the Jeep Patriot, which had inflicted $3,095 worth of damage on the Dodge Caliber when it crashed into the Caliber's rear. Since the 2 vehicles share a platform, engineers were able to simply bolt the front bumper of a Caliber onto the Patriot. This lowered the SUV's bumper nearly 3 inches. The Patriot's new front bumper and the Caliber's rear bumper overlapped more than 3½ inches, compared with less than an inch of overlap for the original equipment.
Damage to the Caliber fell 40 percent to $1,847, and the change shaved $34 off the Patriot's $1,415 repair bill.
For both SUVs, the lower bumpers fit under the original covers, so the modified vehicles didn't look any different. Nor was there any change in approach or departure angles that could affect a vehicle's usefulness off-road and at loading ramps.
"This experiment shows just how easy it would be to design SUVs with effective bumpers," says Joe Nolan, the Institute's chief administrative officer. "By making simple tweaks, manufacturers could help consumers save on repairs and insurance premiums without compromising on styling or function."