스포티지, 투싼 지붕강도 시험 결과 최하위... IIHS - small SUV roof strength test
by 3sun2009. 3. 25.
미국 고속도로안전보험협회(IIHS)는 24일 소형 스포츠다목적차량(SUV) 16개 모델을 상대로 한 지붕강도 시험의 결과를 발표했다.
지붕이 5인치 찌그러지기 전까지 차체 지붕이 차량 무게의 4배를 견디면 '우수'(Good), 3.25배를 버티면 '적합'(Acceptable), 2.5배를 견디면 '한계'(Marginal), 그 이하면 '미흡'(Poor) 등급이 주어졌다.
IIHS는 이번 평가가 SUV의 경우 전복 사고에서 차체 지붕이 탑승객의 안전을 위협할 가능성이 커 새롭게도입된 것이라고 설명했다. 미국에서 연간 1만 명 이상이 전복사고로 숨지며 특히 SUV 차량의 사망사고 중 59%는 전복과 연관이 있다고 밝혔다.
IIHS는 기본적으로 2009년 모델 차량을 대상으로 검사를 실시했지만, 스포티지와 엘레멘트에 대해서는 차체 지붕이 2009년형과 동일한 2008년형을 사용했다고 밝혔다.
한국 현대자동차의 투싼과 기아자동차의 스포티지는 4단계 등급 중
최하위였다. 기아자동차 미국 법인의 알렉스 페도락 대변인은 이번 평가에 대해 "IIHS 자체적인 것으로써 복잡한 상황에서 차량이
승차자의 안전을 보호하는 능력을 완전히 평가하지 못했다"며 2005년 이래 모든 스포티지 차량에 차체자세제어장치(ESC,
Electronic Stability Control)를 기본적으로 장착하고 있다말했다.
[1500파운드(680kg)의 무게로 눌렀을 때 변형정도 비교. 왼쪽 스포티지, 오른쪽 티구안]
Roof strength is focus of new rating system;
4 of 12 small SUVs evaluated earn top marks
ARLINGTON,
VA — The Insurance Institute for Highway Safety is launching a new roof
strength rating system to help consumers pick vehicles that will help
protect them in rollover crashes. Twelve small SUVs are the first to be
put to the test. Only 4 earn the top rating of good. The Volkswagen
Tiguan has the strongest rated roof, and the Kia Sportage has the
weakest among the 2008-09 models evaluated.
This
new rating system is based on Institute research showing that occupants
in rollover crashes benefit from stronger roofs. Vehicles rated good
must have roofs that are more than twice as strong as minimum federal
safety standards require.
The Tiguan, Subaru
Forester, Honda Element, and Jeep Patriot earn good ratings. The Suzuki
Grand Vitara, Chevrolet Equinox, Toyota RAV4, Nissan Rogue, and
Mitsubishi Outlander are rated acceptable. Roofs on the Honda CR-V and
Ford Escape are marginal, and the Kia's is poor.
"We
anticipate that our roof strength test will drive improved rollover
crash protection the same way our frontal offset and side impact
consumer test programs have led to better protection in these kinds of
crashes," says Institute president Adrian Lund.
Institute
research indicates that roofs have gotten stronger during the past few
years. Part of the reason is that manufacturers have made structural
improvements to earn better front and side ratings in Institute crash
tests. Strong A and B pillars help prevent intrusion in these types of
crashes and also help hold up the roof.
"It's not
surprising that Volkswagen and Subaru earn good ratings in our new roof
test because these automakers were among the first to ace our front and
side tests," Lund points out.
More than 10,000 people a
year are killed in rollovers. When vehicles roll, their roofs hit the
ground, deform, and crush. Stronger roofs crush less, reducing the risk
that people will be injured by contact with the roof itself. Stronger
roofs also can prevent occupants, especially those who aren't using
safety belts, from being ejected through windows, windshields, or doors
that have broken or opened because the roof has deformed. Roofs that
don't collapse help keep people inside vehicles as they roll.
Any
vehicle can roll in a crash, but the problem is worse in some kinds of
vehicles than others. About 25 percent of occupant deaths in crashes of
cars and minivans involve rolling over. For SUVs, this proportion jumps
to 59 percent.
The best way to prevent the deaths is to
keep vehicles from rolling over in the first place. Electronic
stability control is significantly reducing rollovers, especially fatal
single-vehicle ones. When vehicles do roll, side curtain airbags help
protect the people inside. Belt use is essential.
How roofs are evaluated:
In the Institute's roof strength test, a metal plate is pushed against
1 side of a roof at a constant speed. To earn a good rating, the roof
must withstand a force of 4 times the vehicle's weight before reaching
5 inches of crush. This is called a strength-to-weight ratio. For an
acceptable rating, the minimum required strength-to-weight ratio is
3.25. A marginal rating value is 2.5. Anything lower than that is poor.
The ratings depend on vehicle weight, which in turn
depends on options like engine size and 2-wheel versus 4-wheel drive.
The Institute bases its ratings on a typical small SUV, which tends to
be 4-wheel drive and comes with a 4-cylinder engine and automatic
transmission. Heavier and lighter versions of these vehicles are
available, and their actual rollover injury risk would vary by small
amounts. The ratings provide an indication of the relative risk of
similarly equipped vehicles.
The small SUVs that did
well have roofs that are 2.5 to 3.5 times stronger than the minimum
federal safety standard for roof strength. The National Highway Traffic
Safety Administration proposes a new standard but not as tough as the
Institute recommends. The agency has argued that upgrading the
requirements would have only a limited effect on rollover deaths and
injuries. Institute research indicates otherwise.
"Our
research shows that a strength-to-weight ratio of 4 reflects an
estimated 50 percent reduction in the risk of serious and fatal injury
in single-vehicle rollover crashes compared with the current federal
standard of 1.5," Lund explains.
Cars have been built
to meet the same roof crush standard, Federal Motor Vehicle Safety
Standard 216, since 1973. The rule was extended in 1994 to include all
passenger vehicles up to a gross weight rating of 6,000 pounds. Many
SUVs and pickups are heavier, so they're exempt. In 2005, the
government proposed an upgrade to cover these larger vehicles and
require the roofs on all passenger vehicles to have a
strength-to-weight ratio of 2.5. Many vehicles already meet this ratio
and would earn only a marginal rating in the Institute's new roof
strength test. A final rule is still pending.
Roof ratings added to award criteria: A good roof strength rating will be a new requirement to earn the Institute's Top Safety Pick
award for 2010. This is the second time criteria for this award have
been tightened since the first winners were announced in 2005.
Availability of electronic stability control became a requirement
starting with 2007s.
"Adding Top Safety Pick
criteria means we'll see fewer winners in 2010," Lund says. A record 73
vehicles have qualified for the 2009 award so far, and 8 of the 2009
winners are among the 12 small SUVs the Institute just tested for roof
strength. However, only 3 of the 8 — the Tiguan, Forester, and Element
— have the roof strength to qualify for next year's award. Next the
Institute will assess roof strength of minicars and midsize cars.
