Have a look at this link. Maybe it should shed some more light on what I typed earlier.
https://www.healthychildren.org/English ... ilies.aspxdogg wrote:
If only the car's seatbelts are holding down the booster seat, in the event of an accident, wouldn't it's considerable weight press against the child's bday if there's nothing else tethering it?
A booster seat is not that heavy. Typically a dedicated booster seat is 10 or less pounds in weight. They key to using booster seat with vehicle seat belts is proper placement of the shoulder strap and the lap strap. That is why good booster have a specific path to route the vehicle's seat belt so that the shoulder strap is properly positioned across the child once he/she is seated. This is where the height of the child is important.
I use a Britax Parkway for my 10 year old. In addition to the shoulder positioning route, there is also a crotch loop to ensure that the lap belt is properly positioned on the child.
You can glean that if a child is transitioned too early to a booster seat, there is a real risk of improper restraint in the event of an accident and even the real possibility of the child slipping out of the seat and well....
However, once the child is properly seated in the booster seat and the vehicle's set belts are properly routed, then in impact, the seat belt restrains itself and the effect is the same as that on an adult. I cannot see any added risk of crushing but as with everything else, the momentum of the vehicle in the crash is transferred to the body during impact. So the greater the momentum the greater the chance of some injury or bruising due to being restrained in an impact. Truth be told, I don't think any car seat manufacturer would ever allow a seat to be sold or used if any of your concerns were realised. Remember the booster seat sits on the vehicle seat and the vehicle seat belt restrains the child in the booster seat.
If however you are using a forward facing 5 point harness, then either latch (or isofix) and top tether OR the vehicles seat belt and top tether is used to secure the seat to the vehicle and then the 5 point harness of the car seat secures the child to the seat.
Never use a forward facing 5 point harness car set without top tether, unless the manufacturer specifically advises so.
dogg wrote:
And just the seatbelts hold it in place when its not in use?
When not is use, remove the seat from the car or put in the trunk. if not possible, then yes, secure the booster in place with the vehicle set belt to prevent it from becoming a projectile in a collision. The Britax Parkway I have has clips that attach to the latch (or isofix) anchors in the vehicle for the sole purpose of securing the seat whilst not in use and to prevent it from becoming a projectile. When my 10 year old is seated, the vehicle's seat belts are used.
Dogg, I'd really advise that unless your 5 year old is either very tall or a bit hefty, you stick to the 5 point harness in forward facing mode. I read through the manual you sent and there's really no need to rush to transition to a booster seat, I'd also advise that when you are ready to transition to a booster seat that you get the dedicated booster that is much lighter and less cumbersome to work with.
Remember also that the car seats also have a life and this is really due to the plastic becoming weaker due to use and exposure to the sunlight and heat. PTN - have you ever seen what PVC pipe gets like if left exposed for a length of time in the weather? The pipe becomes brittle and will crack or deform when cut. This is the same concept that applied to the plastics in a car seat and why its advised to replace after a few years. Yeah I know that it could also be a marketing gimmick in order to boost sales of car seats, yada yada. But as I said a while ago, I won't risk being frugal when it comes to the safety of my lil ones in what is the greatest and most deadly weapon of all times (i.e. the vehicle).