Crew cab pickups are more popular than ever for their practicality and ability to haul families. However, just because they can fit more people, doesn’t mean they can protect them in an accident, new research from the Insurance Institute for Highway Safety (IIHS) finds.

The safety organization subjected the 2023 Ford F-150, Chevrolet Silverado, Ram 1500, and Toyota Tundra to its updated “moderate overlap front” crash test and its side crash test. While the large pickups performed well in the latter test (all received “good” ratings but the Silverado, which got an “acceptable” rating), they struggled in the former.

The Toyota Tundra Crew Cab was the best performing in the group, receiving a “marginal” rating in the moderate overlap front crash test. However, the American pickups all received “poor” ratings, because of their lack of protection for rear seat passengers.

Read: Minivans Are Big On Space, But Not Safety, IIHS Finds

All four pickups managed to protect their front seat passengers, but in the back the trucks struggled to keep a small dummy’s head, neck, and chest safe. The biggest problem for the dummy (which is designed to simulate a 12-year-old) was “submarining,” according to the IIHS.

All four pickups received “poor” ratings in the rear passenger restraint and kinematics portion of the test, because they allowed the dummies to slide down and forward, which is called submarining. In addition, the belt forces were too high in the American pickups.

While the tests aren’t great, pickups aren’t the only vehicles struggling in the updated IIHS test. Previously, the organization (and others) only tested for front seat safety, which naturally encouraged automakers to invest time and effort into focusing on those occupants.

However, in recent IIHS research, it determined that as front seat safety has improved, rear seat safety has lagged behind, prompting it to now perform crash tests that consider the first and second rows of a vehicle.

In order to receive the organization’s “Top Safety Pick” award, a vehicle must perform well all around, not just in the front. As a result, none of the pickups mentioned above are eligible for the award. However, the IIHS warns that despite the results of these tests, the rear seat is still the safest place for small children, who could be injured by airbags. In addition, the test does not look at car seat safety.