Diono Car Seats Allow Parents to Fit Three in the Backseat

When baby makes three kids in the backseat, it’s often time for parents to start looking for a larger car. However, there are some who instead look for a way to fit three child-safety seats across their current car’s bench seat. Car-seat manufacturer Diono offers two lineups of convertible/booster seats that not only fit three across some cars, but these seats also fit kids who weigh as little as 5 pounds to as much as 120 pounds.

Related: Which Cars Fit Three Car Seats?

The Diono Radian lineup — the R100, R120 and RXT — is the company’s flagship car-seat line. The well-known Radians are just 17 inches wide, which makes it easier for parents to fit three car seats across a backseat.

Introduced earlier this summer, the Diono Olympia, Rainier and Pacifica car seats improve on the Radian lineup’s design, though at 18 inches, they’re slightly wider than their predecessors.

“Generally, the Radian Convertible+Booster needs approximately 51 inches to fit three across,” Allana Pinkerton, Diono’s child passenger safety advocate, said in an email.

Besides the slight difference in width, the Olympia, Rainier and Pacifica convertibles have deeper sidewalls for better side-impact crash protection and higher weight limits for rear- and forward-facing positions, Pinkerton said. These seats also have a longer expiration date of 12 years from the date of manufacture, which Pinkerton says is a car-seat industry first. The Radian car seats have a 10-year expiration date.

We put the Pacifica, Olympia and Radian RXT to the test at our Chicago headquarters; we installed them in our long-term test cars and had staffers try them out at home with their children.

Tests

Before installing Diono’s car seats, we tried to install the three car seats we normally use in our Car Seat Checks across both of our long-term test cars, the 2014 Jeep Cherokee, a compact crossover, and our 2014 Chevrolet Impala, a full-size sedan. Neither car could fit our three normal-sized seats across its backseat. While the results didn’t surprise us with the Cherokee, some might question why a full-size sedan can’t manage to fit three car seats. In its 2014 redesign, the Impala’s rear-seat hip room shrunk by 3.1 inches from 57.2 inches in the 2013 Impala to 54.1 inches in the current model.

Using the combination of Diono’s car seats, we had much better luck fitting three seats across our test cars. In the Impala, we were able to easily fit the three Dionos in the forward-facing position across its backseat.

At 49.9 inches, the 2014 Cherokee has significantly less rear hip room than the Impala. That’s no surprise. What is surprising is we were able to fit the three Dionos into the Cherokee’s backseat. It was a tight squeeze, but they all fit. We used a combination of seat belts and Latch systems to get all three seats installed. We might have had even better luck had we had three of the 17-inch-wide Radian car seats.

We also performed the ultimate test with these car seats: We had our kids ride in them.

Managing editor David Thomas, a father of two, found the Radian RXT to be sturdy and made of good-quality materials.

“I would put it right on par with the Britaxes we’ve bought in terms of quality, if not a step above, which makes the high prices ‘worth’ it,” Thomas said, who also appreciated that the narrow seat allowed him to fold down the backseat armrest between his kids’ car seats.

“This is a heavy car seat to lug around, but I appreciated its substantial overall construction,” said Mike Hanley, research editor, about the Olympia car seat his son tested. “I especially liked the Diono’s cinching system, which made it easy to get the harness tight but also easy to release and loosen when it was time to get out. The padded strap covers and buckles seemed like they’d be able to take the repeated abuse car seats get.”

I used the Diono Pacifica as a booster seat for my 7-year-old. He wasn’t thrilled about sitting in a high-back booster seat (he uses a backless booster), but once coaxed into it, I found that it fit him well and the seat belt was properly positioned on him.

One thing that Hanley, Thomas and I agreed on is the Diono car seats are incredibly heavy.

Hanley also found it difficult to tightly cinch the Diono Olympia’s Latch strap. “Unlike our Britax seat, which has Latch anchors that you tighten individually, the Diono system has Latch anchors attached to a strap that you cinch. This system made it harder to secure the seat; I felt like there was more movement than with our Britax seat.”

Even with the drawbacks, the Diono car seats could be just what parents of three children need. While the car seats are pricey, they’re a lot cheaper than a new car.

Cars.com photos by Evan Sears and David Thomas