As babies mature---especially as they get close to a year +, they no longer need teh 45 degree recline that a newborn does to keep their airway open.
When you switch to a
convertible seat, you can install the seat a bit more upright. Most
convertibles take up less space
RF than the infant only seats that were in the same place.
Also--you don't want to turn your child
FF until they have outgrown the limits of the
convertible RF.
RF is the safest way to ride---I wish I could do it!
Susan