Car seats that harness above 40lbs

[usernametaken]

Are there any UK car seats that will keep a child in a 5 point harness above 40lbs?

We have Britax First Class si that will do until 40lbs (fast approaching). We'd like to keep DD in a 5 point harness for far longer.

I've seen US seats that will harness to 85lbs, but they dont seem to be available here and all use some sort of Latch system...no idea what that is....guessing it is similar to isofix (which we dont have)!

Many thanks

I seem to remember from when I was investigating car seats for my very tall sons who I wanted to keep in harnesses (!) longer, that the weight of the child is very important in whether you use a harness. A child over 40lbs would be too heavy to be restrained by a harness in the event of an impact and is far safer in a normal seat belt and high back booster.
I didn't find any harness seats that were recommended for over 40lbs in the UK, and I looked quite hard as DS2 will be in a normal seat belt in high back booster on his 2nd birthday at his current rate of growth.
When he outgrew the Britax seat (humpf show me a child who is still in one of those at 4 like the label says!) we put him in a high back booster/seat that has a harness and then converts to using the normal seatbelt, but again the harness is only recommended till 40lbs.
DS1 was in a normal seat belt with high back booster from 2.3yo and is fine with it btw.

britax used to do one called an elite that used a harness above standard weight limits.

the other option is SN seats.

elite