The Insurance Institute for Highway Safety (IIHS) recentlytested four minivans for protection in small overlap front crashes,and only one vehicle's performance was "acceptable."

The small overlap test replicates what happens when the frontcorner of a vehicle collides with another vehicle or an object likea tree or utility pole. In the test, 25% of a vehicle's front endon the driver side strikes a rigid barrier while traveling at 40mph.

According to IIHS, this type of crash bypasses a vehicle's mainenergy-absorbing structure. Crashes like these are difficult forminivans to handle because they are typically built on carplatforms, but are wider than cars -- meaning more of the vehicleis located outside the main structure.

Vehicles tested can earn a "Good," "Acceptable," "Marginal," or"Poor" rating overall and in six different categories, includingseverity of injury to crash test dummies.

The test performed by IIHS recreated some of the worst possibleoutcomes for small overlap front crashes, and three of the minivanstested earned "Poor" ratings.

Click through to see the best and worst minivans for safety insmall overlap front crashes, as ranked by IIHS.

1. Honda Odyssey

IIHS tested the Honda Odyssey last year. The van earned a "Good"rating in the small overlap crash test, making it one of IIHS' TopSafety Pick+ award winners.

Vehicles with "Good" or "Acceptable" small overlap ratings,along with "Good" ratings in the moderate overlap front, side, roofstrength, and head restraint tests, qualify for the Top Safety Pickaward. Vehicles that meet those criteria and also earn a basic orhigher rating for front crash prevention qualify for the Top SafetyPick+ award.

(AP Photo/American Honda Motor Co., Inc.)

2. Toyota Sienna

The Toyota Sienna is the only vehicle tested this year to earn arating comparable to the Honda Odyssey. But it's not all goodnews.

Toyota modified the front structure of the 2015 model of theSienna in an attempt to improve small overlap protection. Despitethis, the Sienna didn't hold up well in the test. Intrusionmeasured 5-1/2 inches at the upper door hinge pillar and instrumentpanel. In the crash, the dummy's head contacted the front air bag,but then immediately slid off the left side. The seat belt alsoallowed the dummy to move too far forward.

However, what helped Sienna achieve its "Acceptable" rating wasthe side curtain airbag, which deployed and had sufficient forwardcoverage to protect the dummy's head from intruding parts of thestructure. Measures taken from the dummy showed that the risk ofany injuries would be low in a crash of this severity.

3. Chrysler Town & Country

The Chrysler Town & Country earned an overall "Poor" rating,with poor marks in structure damage as well as hip and thigh andlower leg and foot injuries.

In the crash, Town & Country's structure collapsed aroundthe dummy. Intrusion measured 15 inches at the lower hinge pillarand the instrument panel.

The skin on the dummy's left lower leg was gouged by theintruding parking brake pedal, and its left knee skin was torn by asteel brace under the instrument panel. The head barely contactedthe front airbag before sliding off and hitting the instrumentpanel, as the steering column moved to the right. The door sill andthe steering column both moved in toward the driver. The sidecurtain airbag deployed but lacked sufficient forward coverage.

Measures taken from the dummy indicate that injuries to the lefthip, left knee, and left lower leg would be likely in a crash ofthis severity.

4. Dodge Grand Caravan

Results for the Chrysler Town & Country also apply to theDodge Caravan, its twin.

The Caravan received the same overall "Poor" rating, with "Poor"ratings in structure and left hip and thigh and lower leg and footinjuries.

5. Nissan Quest

The Nissan Quest was the most unsafe minivan tested by IIHS inthe small overlap front crash test, despite earning "Good" ratingsfor restraints and kinematics.

The Quest's structure was pushed in nearly two feet at the lowerhinge pillar, and the parking brake pedal moved 16 inches towardthe driver. As a result, the dummy's left leg was trapped betweenthe seat and instrument panel, and its right foot was caughtbetween the brake pedal and toe pan. IIHS technicians had to cutthe entire seat out and then use a crowbar to free the rightfoot.

The Quest's "Good" rating for restraints and kinematics isdeceiving. This rating measures how well the seat belt and airbagswork to control the dummy's movement. In the Quest, the dummy washeld in place by the intruding structure, and the airbag was shovedinto its face, keeping the measured risk of head injury low.

The forces measured all along the dummy's left leg, from thethigh to the foot, were very high, in some cases exceeding thelimits of the sensors. According to IIHS, a real person in thiscrash would be lucky to ever walk normally again. A broken rightfemur also would be possible.

(AP Photo/Nissan, Mike Ditz)