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New Diono child car seat claims to be the ultimate Group 0-2 seat

Which? looks at the claims behind the car seat

Diono Radian 5 child car seat

Diono says the new Radian 5 child car seat is a unique Group 0-2 child car seat

Child car seat manufacturer Diono has launched a new and unique extended rear-facing child car seat with a five point harness. 

The new child car seat from Diono, the Radian 5, is an extended child car seat that is designed to last your child from birth until they are seven years old. 

It’s the first of its kind to have a five point harness when the child is both rearward and forward facing. A five-point harness can help spread the force of a crash across your child’s body to help reduce injury, and also helps keep the shoulder straps in place.

We’ve tested child car seats from a huge range of brands, including Diono, Britax, Chicco, BeSafe, Babystyle and Graco. Our child car seat reviews reveal 11 Don’t Buy child car seats we believe you should avoid.

Extended child car seats

Diono claims that the Radian 5 is suited for children from birth to 25kg, which is around seven years old. 

Children change a great deal between these ages, so an extended child car seat needs to protect them in different ways throughout this time. That’s why our tests have uncovered a number of very poor Group 0/1/2 car seats.

With the new Diono you can keep your child rear-facing until they grow out of the seat. Keeping your child rear-facing for as long as possible is the safest option, so this is a great bonus. 

Another key feature of the new Radian 5 is that it’s one of the only child car seats that allows you to use a five point harness when facing forward, until your child is 25kg.

Child car seat safety

Made of a unique steel frame and metal side walls, Diono claims that the seat is ultra-strong, durable and protective. We haven’t tested this car seat in our unique lab tests, but we will do as soon as possible. 

Although this steel frame could be a benefit, it does make it extremely heavy and large, although that is the case with many extended child car seats.

Like many Group 2 child car seats, the Radian 5 is secured to the car using a seat belt instead of Isofix. This is because Isofix connectors are not strong enough to hold car seats with larger children in place, so on a group 2/3 seat are mainly there to help keep the seat in place when it’s not being used. 

Also, our tests have found many Best Buy child car seats that use Isofix. 

More on this…

  • See our expert advice on choosing the best child car seat
  • Find out how we go further than the standard to test child car seats
  • Get the best for you and your baby with a Best Buy pushchair
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