The basics, for dummies :) Is this:
The current standards are broken into several stages called "Groups". Groups are broken up by weight.
Group 0 is 0-10kg, (0-9 months) and Group 0+ which is 0-13kg. (0-15 months)
These are your baby seats with handle, which usually attach to a pushchair. 99% on the market today are G0+ rather than G0. You might find a 0-10kg seat if you're looking at the totally lie-flat type of infant seats, such as the Britax Babysafe.
Group 1 is 9-18kg. (9 months - 4 years) This is typically a forward facing seat with a 5-point harness, but you can also get rear facing seats in this age bracket (called ERF or extended rear facing) or seats with an impact shield cushion which is a different restraint system.
Groups 2 and 3 are booster seats, from 15kg-36kg. (3.5 years+) They don't have a harness at all and use the adult belt. Group 2 is high backed booster whereas Group 3 is low booster, but most cover both groups.
Then you have combinations:
Group 0/1 seats cover roughly birth - 4 years. They start off rear facing and then turn forward facing later. Check the weight limit for rear facing. Some only rear face for Group 0 so up to 10kg. Most rear face for Group 0+ so to 13kg. A few rear face until 18kg, but this is not always clear - check the documentation carefully.
Group 0/1/2 seats do exist but in two markets: The ultra-cheap "bargain bin" seat makers, which I wouldn't recommend at all, and the top range ERF seats which rear face right to the end of Group 2 which is 25kg, or rear face to 18kg and then harness after that. (Most group 2 seats are not harnessed.)
Group 1/2/3 seats are booster seats with an integral removeable harness which is typically removed at 18kg. Sometimes they have a booster cushion instead of a harness.
i-size is the new legislation, which is currently running alongside the R44/04 "Group" system. I-size seats do not have weight classes but are classified on height and they are all rated individually. There aren't many i-size seats on the market at the moment, so I wouldn't worry overly about it. If you buy an i-size infant seat, then you must legally rear face until 15 months. With the Group system, you can turn your child forward facing any time after they hit 9kg (which could be around 6 months). However, it's very unsafe to do so and it's recommended you wait as long as possible to switch to forward facing.
So currently you need to look at options for Group 0 or infant seats. You've got three options to look at.
- Your "typical" bucket seat with handle which can attach to a pushchair.
I'd say the best option for most people, especially if you get a base so you can easily click it in and out. You can bring the sleeping baby into the house, you can put them on the pushchair for quick trips, it's just easy, hassle free and no issues.
- A lie-flat seat which goes sideways in the car.
A good option if you plan to spend lots of time driving as it's better for babies' spines to lie flat. Not an issue if you don't plan on spending more than 2 hours in the car at a time. Also an option for parents who have lots of money, because these are really pricey. Also, they tend to only be Group 0, so you'll need to look at ERF or turn your baby forward facing early, which seems strange when the focus with these is safety. These might be benificial for premature or low birth weight babies.
- A convertible seat which is FF for group 1 or an ERF seat which is suitable from birth.
A good option if you don't care about being able to take the seat out of the car, if you want to use ERF later and the ERF seat you like is suitable from birth, if you want to maximise rear facing time without investing in a more expensive ERF seat, if you only plan on having one child or a large gap (because this seat will be in use for 4 years, as opposed to the other types which are used for about a year and a half max.)
A note on the FamilyFix base - while this might seem like a good deal, it's only a good deal if you're already totally sold on the Pearl as a second seat. (There are two versions, BTW - the 2way Pearl, which is an ERF seat, and the normal Pearl, which is a forward facing Group 1 seat). If you change your mind on the Group 1 seat, then you've effectively wasted money on the base. And again, worth considering whether you plan to have another child within the next four years, because you can't use one base for two seats at once, so potentially you need to buy a second base anyway. I think it's a rather clever marketing trick by Maxi Cosi to make you think you're saving money, when you're not necessarily (and you've also effectively locked yourself into buying their Group 1 seat, because why would you get another when you have a base for that one already?)
With brands - you can pay out for the Which? report, or look it up in your local library, or you can look at the German site ADAC which tests all car seats for safety. If you have Google Chrome you can right click after the page loads and "Translate to English", or just look without it being English - you can choose from the brand in a drop down list near the bottom under "Hersteller auswahren". Roemer is Britax and Peg Perego is Mamas and Papas and the other brands are the same. They show a green-red rating for safety.
Maxi Cosi and Britax have the best reputation, I think Maxi Cosi capitalise on this a bit and overcharge, but their infant seat is very versatile in terms of how many pushchairs it fits on. For infant seats I'd look for nice deep "wings" and overall flatness of seat.
Good luck! :)