A trio of minivans earned mixed ratings in recent crash tests by the Insurance Institute for Highway Safety, although two models earned the institute's Top Safety Pick award.

IIHS recently put the vehicles through its passenger-side small overlap crash test. This test is designed to see how well a vehicle can protect passengers when the front corner of a vehicle collides with another vehicle or a stationary object such as a tree or utility pole. Driver-side small overlap tests began at IIHS in 2012, and passenger-side tests were later added to encourage automakers to add equal protection for both front seat occupants.

Researchers tested the 2018-2019 model years of the Honda Odyssey, Chrysler Pacifica, and Toyota Sienna. Vehicles were ranked in a number of categories on a scale that included good, acceptable, marginal, and poor ratings.

The Odyssey earned a good rating overall, while the Pacifica had an overall ranking of acceptable. The Sienna fell short of the requirements for a Top Safety Pick award, earning only a marginal rating overall.

"In our latest passenger-side tests, we didn't find any performance issues with safety belts or airbags like we did when we evaluated small and midsize SUVs earlier this year and midsize cars last year," said David Zuby, chief research officer at IIHS. "Instead, we saw some structural deficiencies on the right side that still need addressing."

Both the Odyssey and Pacifica had good ratings for driver-side crashworthiness and occupant protection, while the Sienna was rated as acceptable. However, none of the minivans earned a good rating for the passenger-side structure. The Pacifica was rated marginal and the Sienna poor.

IIHS said that while Toyota updated the Sienna in the 2015 model year to improve driver-side protection in small overlap crashes, it did not extend this protection to the passenger side. In the crash tests, the structure on the passenger side crumpled as far as 20 inches into the vehicle cabin.

"The intruding structure crumpled around the test dummy's legs," said Zuby. "A real right front passenger would sustain possible injuries to the right hip and lower leg in a crash of this severity."

Structural intrusion was also a problem on the Pacifica, although sensors on the test dummy indicated that it presented a low risk of injury. The Odyssey's structure held up well enough for it to earn an acceptable rating.

Vehicles must have good ratings in all crashworthiness tests except the passenger-side test to qualify for a Top Safety Pick award. A good or acceptable rating in this test is necessary to qualify for IIHS's top award of Top Safety Pick+.

All three minivans earned good ratings for passenger restraints and kinematics, with the Odyssey and Pacifica getting good ratings across the board. The Sienna was rated good for head and neck as well as chest protection, although the structural intrusion issue lowered the ratings on hip and thigh as well as lower leg and foot protection to acceptable.

IIHS also tested the minivans' LATCH system, or Lower Anchors and Tethers for Children. This system is designed to work with child restraints to simplify the process of adding car seats and booster seats in the back seat.

"Since minivans often serve as family haulers, parents in the market for a new one also should keep in mind where their kids will sit, especially if more than one needs a child restraint," said Zuby.

The LATCH ratings established by IIHS are based on how easy the system is to use, since an easier system will minimize the possibility of mistakes. The Odyssey earned a good+ rating, since it met the criteria for a good rating while also providing additional seating positions with LATCH hardware. The Sienna's LATCH system was rated acceptable, while the Pacifica had a marginal rating.

"The Odyssey is a good example of the steady improvements we have seen in LATCH ratings in just three years," said Zuby. "Honda factored in LATCH when redesigning the Odyssey for 2018, boosting the minivan's rating from acceptable to good+ by making the second-row tether anchors easy to find and the lower anchors easy to maneuver around. In addition, the Odyssey model we tested has two good LATCH seating positions in the second row and two acceptable positions in the third row."

The Dodge Grand Caravan and Kia Sedona were also included in the LATCH testing. Both models earned acceptable ratings.

IIHS noted that the LATCH rating doesn't necessarily influence child safety, since this is determined more by whether the child restraint is properly installed. However, it was more difficult to properly install a child restraint in a vehicle that scored lower in LATCH testing.