Copyright 2000 The Washington Post
The Washington
Post
June 25, 2000, Sunday, Final Edition
SECTION: FINANCIAL; Pg. H01
LENGTH: 1777 words
HEADLINE:
Big vs. Little; Safety Experts, Carmakers Redesigning Behemoths, Small Vehicles
to Improve Unequal Odds of Survival
BYLINE: Frank
Swoboda , Washington Post Staff Writer
BODY:
Last year when Ford Motor Co. introduced the Excursion and
the Navigator, the largest of its sport-utility vehicles, the company made
heavy-duty trailer hitches standard equipment. The decision was made for safety.
It turns out the SUVs were so big, the below-the-bumper hitches kept smaller
cars from sliding under them in rear-end crashes.
"That's why we did
it," said Ford spokeswoman Sara Tachio. "We discovered the safety aspect during
crash testing."
The 300-horsepower, 5,722-pound Lincoln Navigator and
its corporate twin, the Ford Excursion, sum up the problem facing U.S. safety
engineers as they look for ways to change the geometry of cars to make these
behemoths less lethal in crashes with small cars, such as the new 1,900-pound
Honda Insight.
This is no easy task in a nation where nearly half the
family vehicles now produced are pickup trucks, minivans and SUVs--all of which
are considered light trucks. At the same time, the automakers continue to
produce millions of small cars each year to help meet federal
fuel-efficiency standards.
The automakers have a major
stake in promoting sales of light trucks: They are highly profitable, with gains
on some vehicles of more than $ 10,000. Those hefty profits help offset the thin
margins and even losses they absorb on slower-selling small cars. General Motors
Corp., for example, pushes each Cavalier, its best-selling small car, off the
lot at a loss of more than $ 1,000 per vehicle just to avoid the heavy fines
that would result from failing to meet federal mileage standards.
The
financial incentives for building light trucks are so great that GM officials
meeting in Europe last week admitted that the company's North American
operations have essentially become devoted to truck production, and that they
planned to keep it that way for some time to come.
The safety problem
arises from having all those big and small vehicles sharing the same roadways.
Inevitably, the large and the little collide, and the occupants of the latter
take more of the hit. So safety experts and auto engineers are working to
redesign both to reduce the harm.
Kim Hazelbaker, a senior vice
president for the Highway Loss Data Institute, says only half jokingly that if
you really want to make the highways safer, get rid of the small cars.
Hazelbaker crashes cars for a living to see just how safe they are.
Hazelbaker knows that the laws of physics are immutable. Mass kills.
In two-vehicle crashes involving cars and some other type of vehicle
(such as a truck, bus, minivan or SUV), more deaths occur in the cars, according
to a report by Brian O'Neill, president of the Insurance Institute for Highway
Safety.
Or, as Don Vander Lugt, engineering group manager at the GM
truck center, wrote in a paper prepared for the Society of Advanced Engineering
last year, "Fundamental physics and numerous field studies have clearly shown a
higher fatality risk for occupants in smaller and lighter vehicles when
colliding with heavier vehicles."
Still, nearly half of all highway
deaths occur in crashes involving cars hitting other cars, according to
government statistics. Therefore, "automakers should design their cars so
occupants are as safe as possible, without worrying about [the varying sizes of
the vehicles] in crashes," O'Neill wrote in the report. He argues that safety
improvements should be made in vehicles of all sizes.
Clarence Ditlow,
director of the Center for Auto Safety, a powerful safety watchdog group created
by consumer activist Ralph Nader, sees some hope in the fact that the truly
small cars--such as the early Toyota Corollas and Honda Civics--are beginning to
disappear from the market. "The really small car of the mid-1970s is basically
gone. The average small car has gotten bigger," Ditlow said.
Those were
cars with curb weights between 1,800 and 2,200 pounds, vehicles that wouldn't
stand much of a chance against one of today's 5,000-pound Chevrolet Suburbans or
5,700-pound Navigators. But even the newer small cars, such as the modern
Corollas and Civics, are 1,000 pounds lighter than the big Buicks and BMWs and
only half the weight of the big SUVs and pickups.
But the new
gasoline-and-electric hybrid cars, such as the Honda Insight, now weigh less
than 2,000 pounds as manufacturers strip as much weight as possible to achieve
fuel mileage upward of 70 miles a gallon.
Helen Petrauskas, vice
president for environmental and safety engineering at Ford, says the trick is to
keep small cars from getting any smaller and make the bigger vehicles lighter,
while still providing customers with what they want.
One goal for the
automakers is to redesign the big vehicles so they cause less damage and absorb
more of the impact in a crash. "Shape has become important. The geometry is
changing," says Pria Prasad, manager of safety research and development at Ford.
One way is to lower the bumpers of the bigger vehicles. Federal
crash-test regulations require car bumpers to be 16 inches to 20 inches off the
ground. There is no bumper requirement for SUVs and pickup trucks, which can be
as much as five inches higher, especially if they have four-wheel drive.
In a crash between a car and a light truck, the big vehicle's bumper is
like a battering ram. It's even more devastating in side-impact crashes than in
frontal crashes.
A paper prepared for the National Highway Traffic
Safety Administration last year shows the various points a bumper would hit in a
side-impact crash using a 1997 Honda Accord as the test car being hit. A
mid-size Chevrolet Lumina would hit the Accord just above the door sill, the
strongest point of protection on the side of the car. The bumper of a Ford
Explorer, a mid-size SUV, would hit the Accord at just about the lower spine of
the Honda driver. Not only does the Explorer hit the Accord higher on the side,
it also weighs nearly 600 pounds more.
At Ford, the new geometry
involves both the simple and the difficult in vehicle design. The simple
involves such things as the trailer hitch on the big SUVs; the more difficult
changes involve lowering the frames of the big SUVs and pickups while at the
same time making them less rigid so they will absorb more energy in a crash.
The frames on Ford's pickups and SUVs are notched at strategic points to
make them absorb some of that impact by crumpling on impact. It's much the same
as the crumple zones now used in passenger cars.
More important, Ford
has lowered the frame and put a rail across the front of it to further reduce
the possibility of the larger vehicle overriding the smaller one in a crash. But
the frame can be lowered only so much. The trucks and SUVs must clear what is
known as the ramp angle, the angle that allows the vehicle to back down a
loading ramp. To lower the frame, the company has reengineered the suspension
springs.
Some of the changes beginning to take place throughout the
industry are represented in the new Ford Escape, scheduled to go on the market
in the fall. The Escape is a mini-SUV in the same class as the Honda CRV and the
Toyota RAV4. The designers of these vehicles recognize that very few SUVs
actually go off road. Vehicles of this new breed--dubbed "sport-cutes" by some
in the industry--are all-wheel-drive and have no rigid frames. While other SUVs
are built on a truck platform, these share the same unibody construction as most
passenger cars, which are designed to crumple in a crash.
Because of the
unibody construction, a first for Ford SUVs, the Escape is wider and therefore
harder to tip over.
"The intent of this vehicle is not a work truck,"
said Leonard Shaner, the vehicle crash supervisor for the Escape.
In
addition to the unibody frame, the Escape also has high-strength steel-alloy
door frames, a steering column that moves away from the driver as a crash
begins, a structural front beam to avoid override, knee bolsters and optional
side air bags.
"When you have a blank sheet of paper to design the
architecture, you get a less aggressive vehicle," said Shaner, describing how
the Escape was less of a threat to other vehicles than the conventional SUVs.
"We think it's the whole package."
Ford isn't the only manufacturer
dealing with the issue. At the General Motors truck center in Pontiac, Mich.,
engineers have redesigned the frames of the company's large pickups and SUVs to
allow them to collapse in a crash. They have also lowered the frame rails and
put a bar on the front to help prevent the big vehicles from overriding smaller
ones in a crash.
Instead of notching the frame to make it more
collapsible, GM is using a modular three-piece frame and frame rails that are
formed under high water pressure into shapes that allow it to collapse more
easily in a crash. But while the methods are different, the goal is the same: to
make the frames less lethal in a collision.
Like Ford, GM is lowering
the frame and the bumpers as much as possible and adding a tubular structure
across the front of the frame to prevent override and help absorb the energy of
the impact. Vander Lugt, the GM engineer, calls it a "progressive crush."
"A lot of our business is trying to balance a bunch of different
imperatives," he said.
While some engineers focus on the big vehicles,
others are working to provide more protection for the occupants of the smaller
cars, particularly in the case of side-impact crashes. Among the improvements
are side-impact air bags and high-strength alloys around the door frame. Right
now the stiffest point of a car in side-impact crashes is the door sill, well
below the impact point in many collisions.
To help reduce deaths and
injuries in frontal crashes, automakers are putting additional angled supports
under the car hood to help divert the energy of a crash.
The government
is not providing any regulatory guidance to automakers. The government's ratings
of vehicles' performance in frontal crashes apply only to collisions with other
vehicles in the same weight class.
The Center for Auto Safety's Ditlow
sees hope for improving the safety of small cars. And he is encouraged by the
changes he sees in the bigger vehicles, particularly the SUVs. "In the
beginning," Ditlow said, "manufacturers were just taking trucks and converting
them to SUVs."
Asked to grade the auto industry's efforts to deal with
the problems of crashes between vehicles of different sizes, Ditlow gives the
industry a B-plus for awareness and a D-plus for what they're doing about it.
"The real challenge is not that you recognize the problem. The real challenge is
what are you going to do about it," he said.
LOAD-DATE: June 25, 2000
