At what age is it ok to decrease the car seat angle? I keep reading that "for older babies" you don't need the 45 degree angle. The situation I'm in is that I have a 2.5 year old rear facing on the passenger side outboard position, and a 4 month old on the driver side outboard position. (I originally had DS2 in the middle, but DS1 was messing with him when he cried, so I had to move the baby outboard.) DS2 is 4 months and 19.5 pounds. He'll outgrow the bucket probably in 2 or 3 months. I don't think my other convertible car seat will fit outboard at a 45 degree angle. Is it ok to have a 6 or 7 month old in a car seat that's not at a 45 degree angle?
Also, my bucket goes to 22 lbs. Does that mean when baby weighs 22.1 lbs he's too heavy, or just as long as he's not 23?
As soon as the baby can hold his head up, its ok to have it more upright. Its newborns where the angle is an issue because they cant lift their head if it flops too much so they cant breathe.
You can put it more upright and as long as his head is ok even when he sleeps, its fine.
If you can fit an infant seat, you can fit a convertible. Many convertibles take up LESS space than an infant seat (they look bigger, but take up less space front to back). Infant seats must be at 45 degrees but convertibles install more upright.
Rearfacing seats are outgrown when they reach the weight limit (if it says 22lbs, then when he hits 22lbs he is too big), OR if they have less than 1" of plastic shell above the head, whichever comes first.