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Five things you didn’t know about child car seats

Handle bars, car seat fitting, ISOfix and more...

Girl in Maxi-Cosi car seat

Five simple car seat facts that could help protect your little one in a crash

Do you strap your child car seat in without giving it a second thought? Even if you’ve been using car seats for many years, read on to discover five things you probably don’t know about this essential piece of baby and child safety kit.

Which? has been testing car seats for nearly 50 years. We crash tests every car seat we review in two specially designed crash scenarios, to uncover the best and worst. 

Find out which we rate child car seat Best Buys and those we’ve labelled Don’t Buy child car seats

1) Not all car seats fit in all cars

Despite car seats being labelled as ‘Universal’ or ‘Semi-Universal’, it’s still vital to check that any car seat you want to buy will fit in your car, as not all car seats fit in every car. Don’t part with any cash until you are sure the car seat is suitable not only for your car, but all cars you plan to use the seat in. 

Most car seat manufacturers will have a fitting list somewhere on their websites, and your car manufacturer should know which seats can be used with your particular model of car. 

How to fit a child car seat – our exclusive video fitting guides show you how.

dad fitting baby into car seat

Keep your baby rearward facing for as long as possible

2) When to change your seat

Don’t be tempted to change your car seat too early, It’s better to be heavier in the lower group car seat (but no heavier than the weight limit), than to move your baby up to the next stage seat too early.

Babies need different levels of protection to toddlers and older children and they’re particularly vulnerable to injuries caused by impact and uncontrolled movements of their head.

It’s for this reason that we also recommend you keep your baby rear facing until at least 15 months in their baby car seat. Group 1 seats are approved for use from 9kg, but this is very young to be turned forward facing. 

When we surveyed almost 1,500 parents in 2015, almost half (48%) of our respondents weren’t aware it’s safest for a child to travel rearward facing for as long as possible.

The best child car seats for babies – read more on why it’s best to keep babies rearward facing. 

3) What to do with the baby car seat handle

Did you know the carry handle on your baby car seat needs to be locked into a specific position before you set off on a car journey? 

If you’ve been setting this handle neatly out the way before you head off, check your car seat instructions and see what position it needs to be in.  

Some car seat manufacturers also state that the sun shade, when used, can help protect babies from debris in an accident.  

Our car seat reviews include how clear and easy the instructions and warning labels on each seat are to understand. 

maxicosi tobi 2014

Check your headrest and harness is adjusted properly to fit your child

4) Check the height adjustable harnesses/head rests before you buy a new seat

Does your toddler’s car seat seem snug? Is the harness looking like it’s too tight? Before you start to think about a new car seat, check to see if you’ve adjusted the head rest and harness height properly. Most car seats have adjustable head rests and multiple harness height settings so you can adjust the seat as your little one grows. 

The best car seats have harnesses that are automatically adjusted when you pull up on the head rest. This means you don’t have to unthread the harness to adjust it, then do it back up again. This can be fiddly and introduces the risk that you don’t put the harness back correctly, which could reduce the seat’s effectiveness in a crash.  

10 essential car seat fitting checks – check your seat today to keep your little one safe.

5) How ISOFIX on Group 2/3 seats works differently

ISOfix connectors are designed to make installing a car seat much easier, which lowers the risk of getting it wrong. Even a Best Buy car seat won’t offer full protection in a crash if it’s not been installed properly. 

The Isofix connectors on a Group 2/3 seat (15 – 36kg, that’s around three-and-a-half/four to 12 years old) don’t work in the same way as they do for a Group 0+ or Group 1 seat. 

Generally the ISOfix connectors on a Group 2/3 seat are not designed as a path for the forces of a car crash. They’re used to mainly keep the seat in place when it’s not in use, so that it doesn’t fly forward and hit you if you had to brake suddenly. It’s the adult seat belt in a group 2/3 seat that helps distributes the force of a crash away from a child’s body. 

But that said, our car seat crash test results do show that ISOfix on Group 2/3 car seats can sometimes help improve a seat’s safety score.

Best child car seats for toddlers and older children – how to protect older children in cars.

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