Most small cars aren’t economical for crash repairs, says a news release from the Insurance Institute for Highway Safety. To assess and compare bumper performance in low-speed impacts, the Institute conducted a series of four crash tests — full front and rear, plus front and rear corner impacts.

While the purpose of a bumper is to absorb the energy of a low-speed collision and slow the vehicles before there’s damage to expensive-to-repair parts like fenders and hoods, modern front-end styling results in bumper designs that can either slide under the bumpers of other vehicles or that simply don’t have enough room to absorb the energy of a low-speed crash. What this means is that even a small impact can cost you big when it comes to new small cars.

The Institute’s findings:

The front bumper of the Ford Focus is tall enough to do a reasonably good job in the full-width test. Repairs cost less than $600. In contrast, damage to the Hyundai Elantra of nearly $5,000 in the same test is equal to almost one-third of the car’s sales price.

Underride is a frequent cause of significant damage in the tests, just like in real-world crashes. For example, the front bumpers of the Volkswagen Rabbit and Honda Civic underrode the barrier in the front full-width test resulting in damage to their grilles, hoods, fenders and air-conditioning condensers. Similarly, the Toyota Prius sustained nearly $4,000 damage in the rear full-width test because its bumper is mounted too low to be in position to protect the vehicle’s tailgate, rear body panel and taillights.

In the front corner test of the right side of the Prius, damage was much less, about $1,200, involving the fender and headlight. But had the test been conducted on the left side, the barrier would have crushed a coolant tank which costs more than $1,000 to replace, not including labor.

You can read the full report here.

Photo courtesy of Ford

The redesigned 2009 Acura TSX, a midsize luxury car, wins the Insurance Institute for Highway Safety’s Top Safety Pick award. Winners afford superior overall crash protection among the vehicles in their classes. To qualify, a vehicle must earn the highest rating of good in the Institute’s front, side, and rear tests and be equipped with electronic stability control. The new TSX improved in the side test from acceptable to good and in the rear test from poor to good, compared with the previous model.

“This is the third Acura and the eighth model from Honda to earn our top award,” says Institute president Adrian Lund. “Frontal crashworthiness has improved dramatically for all cars in recent years, but there still are significant differences in how vehicles perform in our side and rear tests.”

In 2007 the Institute made the criteria to earn Top Safety Pick tougher by adding a requirement — winners must be equipped with electronic stability control. Known by different names and called vehicle stability assist on the TSX, ESC helps drivers maintain control in the worst situation — loss of control at high speed — by engaging automatically when it senses vehicle instability and helping to bring a vehicle back in the intended line of travel. ESC lowers the risk of a fatal single-vehicle crash by about half. It lowers the risk of a fatal rollover crash by as much as 80 percent.

“You don’t know what kind of crash you’re going to be in,” Lund says, “so it’s important to choose a vehicle that will protect you in all kinds of crashes.”

You can read the full story at the Insurance Institute for Highway Safety Web site.

The Acura TSX sports a 16-valve, DOHC, 2.4-liter, i-VTEC inline four-cylinder, pumping out 201 horsepower and 172 pound-feet of torque. EPA mileage estimates are 21 miles per gallon city and 30 mpg highway. Its starting price is $28,960.

If you’re thinking of trading in a gas-guzzler for a small — really small — car with better gas mileage and if you’re considering the Smart ForTwo, there’s good news for you today: The Smart ForTwo earned the top rating of good for front and side crash protection from the Insurance Institute for Highway Safety.

“The big question from consumers is, ‘How safe is it?’”, says Institute president Adrian Lund. “All things being equal in safety, bigger and heavier is always better. But among the smallest cars, the engineers of the Smart did their homework and designed a high level of safety into a very small package.”

To read the full review and watch a video of IIHS’s tests, click here.