Britax Rӧmer ADVANSAFIX i-Size Review

Quick Summary: We are big fans of Britax Rӧmer and the great child car seats that they design and make, all in-house in Germany. The ADVANSAFIX i-Size is a great addition to their range, tested to the newer i-Size regulation. It lasts a great amount of time from 15 months up to when your child no longer needs a car seat, even surpassing the 135cm law, up to 150cm. It's a great price when you think how long it will actually last you, meaning you could only need two car seats during their childhood. It has lots of safety features to keep the child safe and comfortable, including the built in SICT and clever SecureGuard. It is easy to install and can also be used in cars without ISOFIX when in high back booster mode. Our only negative point is the maximum height when used with the harness!

Things we love…

The Britax Rӧmer ADVANSAFIX i-Size is based on the ADVANSAFIX IV R, but has been updated and approved to the new i-Size regulation. To do this, it has had to have more safety features to pass. It is suitable for use from 76 to 150cm, which is from approx. 15 months until 12 years old. We are pleased that the newest version of the ADVANSAFIX, as a forward facing only seat, is suitable from 15 months as a minimum, as rear facing is much safer for younger children.

The ADVANSAFIX i-Size is fitted in the car with ISOFIX and top tether when used with the harness from 76-102cm. It is easy to do by pulling the strap at the back to extend the arms and then connecting to your ISOFIX points. The top tether hook attaches to the top tether anchor in your car, which is usually on the back of the seat, accessed from the boot, and then needs tightening until you can see green at the top. Installation when used as a high back booster from 100-150cm can be done with ISOFIX and the vehicle seat belt or just the vehicle seat belt. Handy if you are travelling in a car without ISOFIX!

It's also important to remember to adjust the SICT (side impact cushion technology) after installing. Working in a screw action, you just unscrew the cap at the side closest to the door until it fills the gap between the door and the seat. This reduces the impact of a side collision and absorbs some of the energy that could otherwise be going into the side of the seat and your little one.

As with all Britax Rӧmer car seats, the ADVANSAFIX is designed with the safety of the child at the forefront, so includes lots of features to protect them. The XP-PAD, SecureGuard and SICT all come with this seat. Britax Rӧmer also do the ADVANSAFIX M i-Size that is slightly cheaper and doesn't come with the XP-PAD or SICT. 

The ADVANSAFIX i-Size is suitable from 76cm, which is your average 15 month old. The i-Size regulation means that you can not forward face before 15 months old as a minimum, so this car seat cannot be used before that age. The harness is to be used up to 102cm, and has a higher weight limit of 21kg. This is brilliant for children that are higher weight centile, like our two year old tester at nearly 18kg! Our only issue is that the height of 102cm is not quite up to the height of other car seats that last to 105cm or around 4 years old and 18kg maximum weight. So it could be outgrown in height even if they have weight left.

The harness pads are soft and supportive and covered in neoprene, the same as used in wet suits. This stops the harness from slipping in a collision. The harness height moves up and down smoothly with the headrest, when you press the button at the back. We just wish there were a couple more positions in the height. The headrest is designed in a ‘V' shape to keep their heads safely in the headrest protection, instead of rolling around too much in a collision.

We have been testing with a 2 year old, 5 year old and 8 year old. All children have been comfortable in the seat and supported at the sides and under their legs. With it being a combination seat, we love that you can use the recline right from 15 months up to an older 12 year old child. Our testers all nap on longer journeys, so it's great that the car seat offers an optimum position for them all.

Once the child reaches the maximum height of 102cm or weight of 21kg, it's time for them to change over to using the vehicle seat belt to restrain them in the car. We would always recommend to keep them harnessed for as long as possible. It's easy to put the harness away by tucking it into the inside of the car seat. Great that nothing needs to be removed and potentially lost for future use! You also need to press a button at the back of the seat to enable the headrest to move up into the higher positions. The green belt guides help you place the vehicle seat belt in the correct position over the child. These were formally red, but now green on the i-Size regulation.

The SecureGuard comes into play once you are using the seat as a high back booster. The FLIP&GROW function allows you to turn the harness buckle upside down to reveal the SecureGuard. The SecureGuard adds an extra contact point for the 3-point belt to pass through which helps keep it in the best position over the child's pelvic bones instead of slipping up over their abdominal area.

The XP-PAD is a shock-absorbing foam pad that fits over the horizontal part of the vehicle seat belt when you are using the seat as a high back booster. It is stored in the pouch at the back of the seat when you need it. It is designed to protect the child's neck in a frontal impact and prevents their chin from impacting on their chest. During the review time, our 5 and 8 year old tester found the pad quite a novelty and looked comfortable in the seat, with the edges of the seat belt cushioned.

The car seat can be used for longer as a high back booster, up to 150cm, even though the law is up to 135cm. This extension is great and offers protection for the child longer if you choose. In some European countries, the law is 150cm anyway so allows you to legally travel there too.

The Britax Rӧmer ADVANSAFIX i-Size is quite a slim seat measuring 44cm in width. This is great for people trying to fit three car seats along the back seat for their children.

As a new seat, the ADVANSAFIX i-Size is yet to go through the ADAC testing, but we are keen to see how it does and if it beats the ADVANSAFIX IV R's score of 2.3! We will update our review accordingly once it has.

Things to look out for…

Although we are happy that the newest version of ADVANSAFIX i-Size is tested to the i-Size R129 regulation and so can only be used forward facing from 15 months, we would also advise that it is safer for any child to be rear-facing for as long as possible.

We also wished that even though the harness has a higher weight limit of 21kg, the height guide for the harness is only 102cm, so actually lower than other car seats that can only be used to 18kg or 105cm. A taller slimmer child may have to move from the harness sooner, but a shorter stockier child would last longer.

Our verdict

We are big fans of Britax Rӧmer and the great child car seats that they design and make, all in-house in Germany. The ADVANSAFIX i-Size is a great addition to their range, tested to the newer i-Size regulation.

It lasts a great amount of time from 15 months up to when your child no longer needs a car seat, even surpassing the 135cm law, up to 150cm. It's a great price when you think how long it will actually last you, meaning you could only need two car seats during their childhood.

It has lots of safety features to keep the child safe and comfortable, including the built in SICT and clever SecureGuard. It is easy to install and can also be used in cars without ISOFIX when in high back booster mode. 

Our only negative point is the maximum height when used with the harness!