2006 Subaru B9 Tribeca front crash test
2006 Subaru B9 Tribeca front crash test. Photo: NHTSA

By Tony Whitney

New vehicle shoppers are showing increasing interest in crash-test ratings and how the next vehicle they plan to buy performs in such tests. Part of this curiosity comes from automakers’ advertising campaigns built up around a specific vehicle’s ability to withstand a serious collision.

Bear in mind that today’s new vehicles are designed from the start for crash resistance. Compared to vehicles of years ago, modern cars, SUVs, minivans and pickups feature a multitude of “crush zones” and impact capable structures – not to mention air bags, state-of-the-art seat belts, active head restraints and so on.

The most respected source of occupant safety testing, regardless of where the vehicle is built, is the U.S. National Highway Traffic Safety Administration, commonly known as “NHTSA.” It’s not that Canada doesn’t carry out vehicle crash tests – it does at the Blainville test centre in Quebec. It’s just that the NHTSA tests have become a North American industry benchmark recognized by all automakers marketing their wares on this continent. The tests are independently conducted under stringent and independent conditions. Automakers conduct their own crash-tests, of course, but the NHTSA ratings are regarded as the “gold standard” and highly respected.

2006 Subaru B9 Tribeca
2006 Subaru B9 Tribeca. Photo: Subaru. Click image to enlarge

To cite an example of a highly-rated vehicle and what its maker did to earn a high NHTSA rating, we’ll look at the 2006 Subaru B9 Tribeca. The Tribeca was recently awarded the highest rating NHTSA can give – five stars – in four occupant safety tests. The Tribeca earned top scores for protecting driver and passengers in front impact (driver); front impact (passenger); side impact (front seat) and side impact (rear seat).

The NHTSA estimates that a five-star rating in the 35 mph “front impact” categories means a 10 per cent or less chance of serious injury to a vehicle’s occupants in the event of a crash. In the “side impact” categories you get those five stars for a less than five per cent chance of serious injury to occupants in the event of an impact.

Different automakers have varying techniques for crash proofing their products, though many of them follow similar paths to come up with high NHTSA ratings. These days, the technology involves body structure, seat belts, head restraints and air bags in various locations.

2006 Subaru B9 Tribeca side crash test
2006 Subaru B9 Tribeca side crash test. Photo: NHTSA

Subaru has a philosophy of active and passive safety, with the “active” side of the equation coming from the company’s Symmetrical All-Wheel Drive system that helps avoid accidents in the first place by giving the driver better control over the vehicle. As far a passive safety goes, Subaru uses a combination of body structure and drive-train engineering along with a lengthy roster of safety features that protect the occupants if the worst happens.

The Tribeca’s “Ring Frame Reinforced” body structure disperses collision energy in three directions. According to Subaru, a series of “rings” around the passenger compartment provide protection in collisions of various types. Side impact protection is enhanced by the use of hydroformed centre pillars used along with rugged side door beams. Hydroforming is a process that uses water to form steel body members without creating stress points where failure might occur.

2006 Subaru B9 Tribeca
2006 Subaru B9 Tribeca. Photo: Subaru. Click image to enlarge

Subaru’s horizontally-opposed or “boxer” engine also helps to provide more crush room in front and side impacts. The entire powertrain is designed to slide under the vehicle in a serious collision. Even the spare tire is located so that it won’t intrude into the passenger compartment in a serious rear-ender.

Inside the B9 Tribeca, there are two front “second generation” air bags that don’t deploy at the maximum rate in relatively mild collisions. There are front seat side impact air bags for thorax-area protection and side curtain air bags for protecting the heads of front and middle row occupants. Since the front seat side impact bags are mounted on the seats themselves, they provide protection regardless of how the seat is positioned. The side curtain bags deploy from the headliner. Various sequences of bag deployment are determined by sensors positioned around the vehicle.

Also helping gain top NHTSA ratings are active front head restraints that contribute towards avoiding whiplash injuries, and a safety brake pedal system and driver’s footrest that minimizes lower leg injuries in a head-on crash.

For details of how these tests are conducted and how various products scored, the NHTSA website is www.safercar.gov. Also, see the Insurance Institute for Highway Safety’s (IIHS) web-site www.hwysafety.org. The IIHS conducts 40 mph frontal offset crash-tests.

Connect with Autos.ca