Crushing results of IIHS small pickup truck roof strength test

Most small pickup trucks showed weakness in the latest roof-crush tests performed by the Insurance Institute for Highway Safety (IIHS), with performance trailing small cars and SUVs previously evaluated.

The stringent new roof-crush test from the IIHS measures how far a roof is deformed by a metal plate placed at the right front corner, which presses down with a multiple of the vehicle's weight. The ratings are based on a strength-to-weight ratio, with Good equating to withstanding four times the vehicle's weight before deforming five inches. Out of five 2010-model small pickups evaluated, only one earned the top rating of Good--the Nissan Frontier, which is also sold as the Suzuki Equator.

Roof-crush tests are often characterized as rollover tests, although many organizations, including Consumers Union, have long argued that roof-crush isn't a very good predictor of rollover resistance. Nevertheless we believe that stronger roof structures can still save lives.

IIHS rollover protection ratings:

• Good: Nissan Frontier
• Acceptable: Ford Ranger
• Marginal: Dodge Dakota, Toyota Tacoma
• Marginal: Chevrolet Colorado (also sold as GMC Canyon). The Colorado is also rated Poor in IIHS side-crash test even with standard curtain air bags.

Benefits from a stronger vehicle roof might make some rollover crashes more survivable as well as benefit vehicle structure for other types of crashes. According to the IIHS, a Good rating here reflects an estimated 50 percent reduction in serious or fatal injury risk in single-vehicle rollover crashes.

The IIHS estimates that every year almost 10,000 people are killed in rollover crashes, and rollovers are much more common in SUVs and pickup trucks than in regular passenger cars. In 2008 almost half the occupants killed in pickup crashes were in a truck that rolled over.

To earn a Top Safety Pick accolade from IIHS, vehicles now have to earn a Good rating in the new roof crush test, besides performing well in side, front, and rear crash tests and offer stability control. This change in Ratings requirements resulted in several vehicles getting knocked off the Top Safety Pick list. Currently, no pickup trucks remain Top Safety Picks.