Ever wonder how much safer or less safe a car seat placed in its base vs a car seat placed in the seat and lap-belted in are? I was and started doing a little research on the thing. The short answer is that if you’ve done it correctly, the lap belt is slightly safer than the base. However, most people do not do it 100% correctly.
However, the slightly safer belt assumes you lap belt them perfectly every time, which also involves checking that the angle of the seat is proper, every time, and insure that the lap belt is latched and ratcheted down, every time, and using the correct belting method (over the lap, around the back if your carrier supports it,) every time.
With a base, once you’ve got it installed, you’ve got the angle correct and placing an infant in can be done just by listening for the clicks. Without a base you place them in, angle, attach the seatbelt, lock the seatbelt, ratchet down, and then insure that the car seat is still angled correctly. Give it a wiggle and you’re set.
Physics tends to indicate that a lower to the seat car seat will get less sheering forces than 20 or so pounds placed on three inches of plastic. Imagine holding a 10 pound dumbbell on your shoulder vs arm’s length if this is not clicking for you. This can be argued against based on the center point of a given car in a rollover situation, but that will vary by car so it’s not something particularly generalizable.
The difference is so little it more comes down to just pick what you want to do and go with it. If one of the parents has a compelling reason to not want to have base in car, that’s fine as long as they’re the one buckling up baby every time and will do it right every single time. Remember, this involves making sure the tilt is correct and that the belt is going on properly (I can’t stress enough that if you think it just goes over the lap you need to research whether you can do the European method).
Crash tests indicate, from what I can tell, that properly done the belt is slightly safer. This doesn’t give the whole picture though as after impact you have to remove the car seat and may have to quickly. If you’ve ever fought with a seatbelt before you’ll know where this is probably going. They can be nightmares to remove when they get jammed. You might need a seatbelt cutter or a knife in that situation. Seconds wasted could be the difference between life and death.
Alternately, the shearing impact of a crash breaks the car seat free from the base, or you didn’t click it in well enough, and the infant seat becomes a projectile. Or your sweat or bloodied hands can’t grip the plastic release to remove the seat from the base.
All fun nightmare scenarios. You’re probably more likely to have to contemplate cutting the belt though than anything else. If you travel with a seatbelt cutter in a reachable location or a knife on your person, that probably minimizes that.
But in the end, it’s whatever you’re comfortable with and can do correctly every time as far as I can tell. There’ll be someone disagree, and then someone else will disagree because it’s the internet, but it’s not something that worrying about is going to change that there’s really not much difference and different impact scenarios will play out differently.
For further research:
- CPSafety (belt is safer)
- Mothering forum (both are safe)
- Base is just for convenience (as long as you can strap them in right)
- Car-Seat.org forums (both are safe)
- Honestly just google it and read people arguing for days
Something to note however is there are several references to 90% of seatbelt installs being done incorrectly. Make sure you know the difference between using seatbelt only and seatbelt and shoulder strap install (European method,) and you should be good to go.
Car seat in base vs no base conclusions
Do whatever you want, you can’t predict what type of crash you might be in (40% side, 60% front or rear,) your only control here is placing them in correctly whatever way you do it and having a plan to get them out in the event something malfunctions.
You can, however, make up your own reasons why someone using one or the other methods of securing their infant is a horrible parent, which seems to be a fairly popular thing to do on the internets these days.