Car seat for tall, slim baby

[LiveFatsDieYoGnu]

I'm new to the world of car seats and I'm hoping someone knowledgeable can confirm whether I'm right about our options. DS is nearly 6 months old and a long, thin baby! He's only just over 7 kg (25th centile) but nearly 70 cm tall (91st centile). Clearly he is not going to be ready for a group 1/2 car seat any time soon but his head is starting to approach the top of his current car seat. Am I right in thinking that our best option is to get a group 0+/1 car seat and suck up the fact that we'll probably have to replace it for a group 2 sooner than we might like?

Have a look at 25kg rear facing seats. Some are suitable from 6 months, some closer to 12 months. They will last until at least 4-5 years and then you could buy a high back booster (could be around £40-£50).

Thanks for the suggestion @teaandbiscuitsforme
I hadn't realised there were 25 kg seats that were suitable from so young. I've had a look now and seen the Axkid Minikid, Diono Radian 5 or BeSafe iZi Plus X1 might be suitable. I'll look more into each of them now but would you recommend any of these in particular?

He may surprise you with his growth - he is safe in his infant seat until his head goes above the seatback. He may do more growing in his legs. Also check often seatback extends (mine did, and I didn't realise til I started worrying about dd outgrowing it really young). Also take out any infant boosters bits under the bum, and pull his crotch right towards the crotch buckle.

I would keep him in the infant seat for now and you'll probably find that he'll have another couple of months in it. Is it an i-size one with a height limit or is it just the shell you're worried about? They can grow a bit slower than you would assume. Also do not forget to shimmy him down in the seat a bit - you can gain a whole inch or so from doing this. PP has a good point about checking for newborn wedges under the bum, too.

Of the three you mention I am less keen on the Diono, it's also outgrown by height fairly early (about 122cm compared to 125-128 for most 25kg seats)

The Minikid is supposed to be suitable from birth, but his shoulders do need to meet the lowest harness slot which is generally around 80cm height. Besafe is defo OK from 6 months ish, but it's massive and a pain to install in small cars.

Lastly don't totally panic! DS2 was off the scale for height/length when he was younger but now seems to have caught down a bit and is more between the 90th and 75th centiles so I think he will be OK in the Joie 360 which is what we have for a while longer. He seemed to race up the earlier headrest settings but has been on the same one for nearly a year now and is only just getting snug so I will move it up (to the fourth of six) soon. I went for the Joie 360 as it is a bit taller than most other 18kg seats. I'd avoid an i-size one with a limit of 105cm if you've got a tall baby. The Joie Spin Safe has better side impact protection without the height limit.

If you think you'll have another baby within a couple of years, it's not always a disaster to get an 18kg seat for the first baby as you can move them into a 25kg one and move the younger sibling into the 18kg seat. By the time DC2 needs the larger one, DC1 should be ready for a booster.

Thanks BertieBotts and Bernadette for your advice our current seat isn't an iSize, it's just that his head is approaching the top of the shell - though I've just clicked that his cloth nappy is probably contributing somewhat! I will check for a newborn wedge but I'm pretty sure there isn't one.

To be honest, I don't love our current seat - it was a gift from a family member who bought it for her DD but then for various reasons didn't use it so passed it on to us. Very generous but now I know more about car seats I realise it's not the best, so I'm inclined to replace it with a group 0+/1 anyway. The Joie Spin Safe looks like it will fit our requirements well.